Inspection Glossary

A

Access (To)

That which enables a device, an appliance or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel, door or similar obstruction.

Accessory Structure

A structure that is accessory to and incidental to that of the dwelling(s) and that is located on the same lot.

Addition

An extension or increase in floor area, number of stories or height of a building or structure.

Adhered Stone or Masonry Veneer

Stone or masonry veneer secured and supported through the adhesion of an approved bonding material applied to an approved backing.

AFCI

AFCI is a type of circuit breaker designed to prevent electrical fires by detecting arc faults, which are unintended electrical discharges that can occur in wiring. These breakers automatically shut off the electrical circuit when an arc fault is detected, enhancing safety in homes and commercial properties.

Aid Admittance Valve

A one-way valve designed to allow air into the plumbing drainage system where a negative pressure develops in the piping. This device shall close by gravity and seal the terminal under conditions of zero differential pressure (no flow conditions) and under positive internal pressure.

Air Admittance Valve

Air Break (Drainage System)

An arrangement where a discharge pipe from a fixture, appliance or device drains indirectly into a receptor below the flood-level rim of the receptor and above the trap seal.

Air Circulation, Forced

A means of providing space conditioning utilizing movement of air through ducts or plenums by mechanical means.

Air Conditioner

A system that cools indoor air by removing heat and humidity, typically using refrigerants and a compressor. It helps maintain a comfortable temperature in homes and commercial spaces, especially during hot weather.

Air Filter

An air filter is a device that removes particles such as dust, pollen, and allergens from the air in a heating, ventilation, and air conditioning (HVAC) system, helping to improve indoor air quality and protect the system from damage.

Air Gap, Drainage System

The unobstructed vertical distance through free atmosphere between the outlet of a waste pipe and the flood-level rim of the fixture or receptor into which it is discharging.

Air Gap, Water-Distribution System

The unobstructed vertical distance through free atmosphere between the lowest opening from a water supply discharge to the flood-level rim of a plumbing fixture.

Air-Conditioning System

A system that consists of heat exchangers, blowers, filters, supply, exhaust and return-air systems, and shall include any apparatus installed in connection therewith.

Air-Impermeable Insulation

An insulation having an air permanence equal to or less than 0.02 L/s-m2 at 75 Pa pressure differential as tested in accordance with ASTM E283 or E2178.

Alternating Tread Device

A device that has a series of steps between 50 and 70 degrees (0.87 and 1.22 rad) from horizontal, usually attached to a center support rail in an alternating manner so that the user does not have both feet on the same level at the same time.

Anchored Stone Or Masonry Veneer

Stone or masonry veneer secured with approved mechanical fasteners to an approved backing.

Antisiphon

A term applied to valves or mechanical devices that eliminate siphonage.

Appliance

A device or apparatus that is manufactured and designed to utilize energy.

Asbestos

A naturally occurring mineral that was commonly used in building materials for insulation and fireproofing. Exposure to asbestos fibers can lead to serious health issues, including lung disease and cancer. It is important to have materials tested and properly managed if asbestos is suspected in a property.

Asphalt Shingles

Asphalt shingles are a type of roofing material made from a fiberglass or organic mat coated with asphalt and granules. They are popular for their durability, affordability, and ease of installation, providing effective protection against weather elements while enhancing the aesthetic appeal of a building.

Attic

The unfinished space between the ceiling assembly and the roof assembly.

Attic Access

An opening or hatch that allows entry into the attic space of a building, typically located in a ceiling or wall. This access point is essential for inspecting insulation, ventilation, and structural components within the attic.

Attic Ventilation

Attic ventilation refers to the system that allows air to flow in and out of the attic space, helping to regulate temperature and moisture levels. Proper ventilation prevents heat buildup in the summer and reduces the risk of ice dams in winter, ultimately protecting the roof and extending its lifespan.

Attic, Habitable

A finished or unfinished habitable space within an attic.

Awning Window

An awning window is a type of window that is hinged at the top and opens outward from the bottom, allowing for ventilation while keeping rain out. This design is often used in areas where you want to let in fresh air without compromising protection from the elements.

B

Backflow Preventer

A backflow prevention assembly, a backflow prevention device or other means or method to prevent backflow into the potable water supply.

Backflow Preventer, Reduced-Pressure-Zone Type

A backflow-prevention device consisting of two independently acting check valves, internally force loaded to a normally closed position and separated by an intermediate chamber (or zone) in which there is an automatic relief means of venting to atmosphere internally loaded to a normally open position between two tightly closing shutoff valves and with means for testing for tightness of the checks and opening of relief means.

Backflow, Drainage

A reversal of flow in the drainage system.

Backflow, Water Distribution

The flow of water or other liquids into the potable water-supply piping from any sources other than its intended source. Backsiphonage is one type of backflow.

Backpressure

Pressure created by any means in the water distribution system that by being in excess of the pressure in the water supply mains causes a potential backflow condition.

Backpressure, Low Head

A pressure less than or equal to 4.33 psi (29.88 kPa) or the pressure exerted by a 10-foot (3048 mm) column of water.

Backsiphonage

The flowing back of used or contaminated water from piping into a potable water-supply pipe due to a negative pressure in such pipe.

Backwater Valve

A device installed in a drain or pipe to prevent backflow of sewage.

Balanced Ventilation

Any combination of concurrently operating mechanical exhaust and mechanical supply whereby the total mechanical exhaust airflow rate is within 10 percent of the total mechanical supply airflow rate.

Balanced Ventilation System

A ventilation system where the total supply airflow and total exhaust airflow are simultaneously within 10 percent of their averages. The balanced ventilation system airflow is the average of the supply and exhaust airflows.

Baseboard

A baseboard is a narrow board that runs along the bottom of a wall, covering the joint between the wall and the floor. It serves both decorative and functional purposes, helping to protect the wall from damage and providing a finished look to a room.

Basement

A story that is not a story above grade or a crawl space.

Bathroom Group

A group of fixtures, including or excluding a bidet, consisting of a water closet, lavatory, and bathtub or shower. Such fixtures are located together on the same floor level.

Bay Window

A bay window is a protruding window structure that extends outward from the main walls of a building, typically consisting of a central window flanked by two angled side windows. This design allows for more natural light and creates additional interior space, often enhancing the aesthetic appeal of a room.

Beam

A beam is a structural element that supports loads and spans across spaces, typically made of wood, steel, or concrete. It helps distribute weight from the roof, floors, or other structures to the supports below, ensuring stability and strength in a building.

Bend

A drainage fitting, designed to provide a change in direction of a drain pipe of less than the angle specified by the amount necessary to establish the desired slope of the line (see "Elbow" and "Sweep").

Boiler

A self-contained appliance from which hot water is circulated for heating purposes and then returned to the boiler, and that operates at water pressures not exceeding 160 pounds per square inch gage (psig) (1102 kPa gauge) and at water temperatures not exceeding 250°F (121°C).

Bond Beam

A horizontal grouted element within masonry in which reinforcement is embedded.

Braced Wall Line

A straight line through the building plan that represents the location of the lateral resistance provided by the wall bracing.

Braced Wall Line, Continuously Sheathed

A braced wall line with structural sheathing applied to all sheathable surfaces including the areas above and below openings.

Braced Wall Panel

A full-height section of wall constructed to resist in-plane shear loads through interaction of framing members, sheathing material and anchors. The panel's length meets the requirements of its particular bracing method, and contributes toward the total amount of bracing required along its braced wall line.

Branch

Any part of the piping system other than a riser, main or stack.

Branch Interval

A vertical measurement of distance, 8 feet (2438 mm) or more in developed length, between the connections of horizontal branches to a drainage stack. Measurements are taken down the stack from the highest horizontal branch connection.

Branch, Main

A water-distribution pipe that extends horizontally off a main or riser to convey water to branches or fixture groups.

Branch, Vent

A vent connecting two or more individual vents with a vent stack or stack vent.

Brick Veneer

A type of exterior wall construction where a single layer of brick is used as a facing over a structural frame, providing aesthetic appeal and some insulation while not serving as a load-bearing element.

Btu/H

The listed maximum capacity of an appliance, absorption unit or burner expressed in British thermal units input per hour.

Building

Any one- or two-family dwelling or townhouse, or portion thereof, used or intended to be used for human habitation, for living, sleeping, cooking or eating purposes, or any combination thereof, or any accessory structure.

Building Code

Building codes are regulations that set the standards for construction and safety in buildings. They ensure that structures are built to withstand environmental factors and are safe for occupancy.

Building Drain

The lowest piping that collects the discharge from all other drainage piping inside the house and extends 30 inches (762 mm) in developed length of pipe, beyond the exterior walls and conveys the drainage to the building sewer.

Building Line

The line established by law, beyond which a building shall not extend, except as specifically provided by law.

Building Permit

A building permit is an official approval issued by a local government agency that allows construction or renovation work to begin on a property. It ensures that the project complies with zoning laws, building codes, and safety regulations.

Building Sewer

That part of the drainage system that extends from the end of the building drain and conveys its discharge to a public sewer, private sewer, individual sewage-disposal system or other point of disposal.

Building-Integrated Photovoltaic Product

A building product that incorporates photovoltaic modules and functions as a component of the building envelope.

Building-Integrated Photovoltaic Roof Panel (Bipv Roof Panel)

A photovoltaic panel that functions as a component of the building envelope.

Built-Up Roof Covering

Two or more layers of felt cemented together and surfaced with a cap sheet, mineral aggregate, smooth coating or similar surfacing material.

C

Cap Plate

The top plate of the double top plates used in structural insulated panel (SIP) construction. The cap plate is cut to match the panel thickness such that it overlaps the wood structural panel facing on both sides.

Capillary Break

A capillary break is a barrier that prevents moisture from moving through porous materials by capillary action, helping to keep water from penetrating into building materials and causing damage.

Carbon Monoxide Alarm

A single- or multiple-station alarm intended to detect carbon monoxide gas and alert occupants by a distinct audible signal. It incorporates a sensor, control components and an alarm notification appliance in a single unit.

Carbon Monoxide Detector

A device with an integral sensor to detect carbon monoxide gas and transmit an alarm signal to a connected alarm control unit.

Carport

A carport is a covered structure used to provide shelter for vehicles, typically consisting of a roof supported by posts or columns, but without fully enclosed walls. It offers protection from the elements, such as rain and snow, while allowing for easy access to the vehicle.

Casement Window

A casement window is a type of window that is hinged on one side and opens outward, typically operated by a crank. This design allows for better ventilation and unobstructed views, making it a popular choice in both residential and commercial properties.

Catch Basin

A catch basin is a drainage structure designed to collect and manage stormwater runoff, preventing flooding and directing water into a drainage system. It typically features a grate on top to filter debris and allows water to flow into an underground pipe system.

Cathedral Ceiling

A cathedral ceiling is a type of ceiling that is characterized by its high, sloping design, which often follows the roofline. This architectural feature creates a spacious and airy feel in a room, enhancing natural light and providing a sense of openness.

Ceiling Height

The clear vertical distance from the finished floor to the finished ceiling.

Cellar

A basement constructed prior to 1990 that does not meet the minimum ceiling height requirements and does not contain living space.

Cement Plaster

A mixture of Portland or blended cement, Portland cement or blended cement and hydrated lime, masonry cement or plastic cement and aggregate and other approved materials.

Certificate of Occupancy

A Certificate of Occupancy is an official document issued by a local government agency that certifies a building's compliance with building codes and other regulations, allowing it to be occupied.

Chimney

A primary vertical structure containing one or more flues, for the purpose of carrying gaseous products of combustion and air from a fuel-burning appliance to the outside atmosphere.

Chimney Cap

A chimney cap is a protective cover placed on top of a chimney to prevent rain, snow, and debris from entering the flue. It also helps to reduce downdrafts and can prevent animals from nesting inside the chimney.

Chimney Connector

A pipe that connects a fuel-burning appliance to a chimney.

Chimney Crown

A chimney crown is the top part of a chimney that protects it from water damage. It is typically made of concrete or masonry and is sloped to direct water away from the chimney structure, preventing moisture from seeping into the chimney and causing deterioration.

Chimney Flue

A chimney flue is a duct or pipe that allows smoke and gases from a fireplace, stove, or furnace to escape safely to the outside. It helps prevent the buildup of harmful fumes inside the home and ensures proper ventilation for combustion appliances.

Chimney Liner

A chimney liner is a protective layer inside a chimney that helps direct smoke and gases from a fireplace or stove safely outside. It also prevents heat transfer to combustible materials surrounding the chimney, reducing the risk of fire and improving the efficiency of the heating system.

Circuit Breaker

A circuit breaker is a safety device that automatically stops the flow of electricity in a circuit when it detects an overload or short circuit, preventing potential electrical fires and damage to appliances.

Circuit Vent

A vent that connects to a horizontal drainage branch and vents two traps to not more than eight traps or trapped fixtures connected into a battery.

Circulating Hot Water System

A specifically designed water distribution system where one or more pumps are operated in the service hot water piping to circulate heated water from the water-heating equipment to fixtures and back to the water-heating equipment.

Cladding

The exterior materials that cover the surface of the building envelope that is directly loaded by the wind.

Cleanout

An access opening in the drainage system utilized for the removal of obstructions. Types of cleanouts include a removable plug or cap, and a removable fixture or fixture trap.

Closet

A small room or chamber used for storage.

Clothes Dryer

A clothes dryer is a household appliance that uses heat and airflow to remove moisture from wet clothing after washing. It typically operates by tumbling clothes in a rotating drum while blowing hot air through them, allowing for efficient drying.

Collapsible Soils

Soils that exhibit volumetric reduction in response to partial or full wetting under load.

Collection Pipe

Unpressurized pipe used within the collection system that drains on-site nonpotable water or rainwater to a storage tank by gravity.

Combination Waste And Vent System

A specially designed system of waste piping embodying the horizontal wet venting of one or more sinks, lavatories or floor drains by means of a common waste and vent pipe adequately sized to provide free movement of air above the flow line of the drain.

Combustible Material

Any material not defined as noncombustible.

Combustion Air

The air provided to fuel-burning equipment including air for fuel combustion, draft hood dilution and ventilation of the equipment enclosure.

Common Vent

A single pipe venting two trap arms within the same branch interval, either back-to-back or one above the other.

Compressible Soils

Soils that exhibit volumetric reduction in response to the application of load even in the absence of wetting or drying.

Condensate

The liquid that separates from a gas due to a reduction in temperature; for example, water that condenses from flue gases and water that condenses from air circulating through the cooling coil in air conditioning equipment.

Condensing Appliance

An appliance that condenses water generated by the burning of fuels.

Conditioned Air

Air treated to control its temperature, relative humidity or quality.

Conduit

A conduit is a tube or channel used to protect and route electrical wiring in a building. It helps prevent damage to the wires and ensures safety by keeping them organized and secure.

Construction Documents

Written, graphic and pictorial documents prepared or assembled for describing the design, location and physical characteristics of the elements of a project necessary for obtaining a building permit. Construction drawings shall be drawn to an appropriate scale.

Contamination

A high-hazard or health-hazard impairment of the quality of the potable water that creates an actual hazard to the public health through poisoning or through the spread of disease by sewage, industrial fluids or waste.

Continuous Waste

A drain from two or more similar adjacent fixtures connected to a single trap.

Control, Limit

An automatic control responsive to changes in liquid flow or level, pressure, or temperature for limiting the operation of an appliance.

Control, Primary Safety

A safety control responsive directly to flame properties that senses the presence or absence of flame and, in event of ignition failure or unintentional flame extinguishment, automatically causes shutdown of mechanical equipment.

Convector

A system incorporating a heating element in an enclosure in which air enters an opening below the heating element, is heated and leaves the enclosure through an opening located above the heating element.

Core

The lightweight middle section of a structural insulated panel, composed of foam plastic insulation, that provides the link between the two facing shells.

Corrosion Resistance

The ability of a material to withstand deterioration of its surface or its properties where exposed to its environment.

Court

A space, open and unobstructed to the sky, located at or above grade level on a lot and bounded on three or more sides by walls or a building.

Crawl Space

A crawl space is a narrow, unfinished area beneath a building, typically between the ground and the first floor, allowing access to plumbing, electrical wiring, and insulation. It helps with ventilation and moisture control but can also be prone to issues like mold and pests if not properly maintained.

Crawl Space Encapsulation

Crawl space encapsulation is the process of sealing off a crawl space from the outside environment, typically using a vapor barrier and insulation. This helps to prevent moisture buildup, mold growth, and pest infestations, improving air quality and energy efficiency in the home.

Crawl Space Vent

A crawl space vent is an opening in the foundation of a building that allows air to circulate in the crawl space area. Proper ventilation helps to reduce moisture buildup, which can prevent mold growth and improve air quality in the home.

Cripple Wall

A framed wall extending from the top of the foundation to the underside of the floor framing of the first story above grade plane.

Cripple Wall Clear Height

The vertical height of a cripple wall from the top of the foundation to the underside of floor framing above.

Cross Connection

Any connection between two otherwise separate piping systems that allows a flow from one system to the other.

Cross-Laminated Timber

A prefabricated engineered wood product consisting of not less than three layers of solid-sawn lumber or structural composite lumber where the adjacent layers are cross-oriented and bonded with structural adhesive to form a solid wood element.

Crown Molding

A decorative trim that is installed at the junction where walls meet the ceiling, often used to enhance the aesthetic appeal of a room. It can vary in style, size, and material, adding character and elegance to both residential and commercial spaces.

Curtain Wall

A curtain wall is a non-structural exterior wall that is typically made of lightweight materials such as glass or metal. It is designed to protect the building from weather elements while allowing natural light to enter, without bearing any of the building's weight.

D

Dalle Glass

A decorative composite glazing material made of individual pieces of glass that are embedded in a cast matrix of concrete or epoxy.

Damper

A damper is a device used in heating, ventilation, and air conditioning (HVAC) systems to regulate airflow. It can be manually or automatically adjusted to control the amount of air entering or leaving a space, helping to maintain comfortable temperatures and improve energy efficiency.

Damper, Volume

A device that will restrict, retard or direct the flow of air in any duct, or the products of combustion of heat-producing equipment, vent connector, vent or chimney.

Dead Loads

The weight of the materials of construction incorporated into the building, including but not limited to walls, floors, roofs, ceilings, stairways, built-in partitions, finishes, cladding, and other similarly incorporated architectural and structural items, and fixed service equipment.

Deck

A deck is an outdoor structure, typically made of wood or composite materials, that extends from a building and is used for recreational purposes, such as dining, lounging, or entertaining. It is often elevated above the ground and may include railings, stairs, and various design features.

Decorative Glass

A carved, leaded or Dalle glass or glazing material with a purpose that is decorative or artistic, not functional; with coloring, texture or other design qualities or components that cannot be removed without destroying the glazing material; and with a surface, or assembly into which it is incorporated, that is divided into segments.

Developed Length

The length of a pipeline measured along the center line of the pipe and fittings.

Diameter

The nominal diameter as designated by the approved material standard.

Diaphragm

A horizontal or nearly horizontal system acting to transmit lateral forces to the vertical resisting elements. Where the term "diaphragm" is used, it includes horizontal bracing systems.

Dilution Air

Air that enters a draft hood or draft regulator and mixes with flue gases.

Direct System

A solar thermal system in which the gas or liquid in the solar collector loop is not separated from the load.

Direct-Vent Appliance

A fuel-burning appliance with a sealed combustion system that draws all air for combustion from the outside atmosphere and discharges all flue gases to the outside atmosphere.

Dishwasher

A dishwasher is a kitchen appliance designed to automatically clean dishes, utensils, and cookware by spraying hot water and detergent, followed by rinsing and drying.

Door Frame (Jamb)

A door frame, also known as a jamb, is the structural component that surrounds a door, providing support and stability. It consists of vertical pieces (the side jambs) and a horizontal piece (the head jamb) at the top, creating a frame that holds the door in place and allows it to swing open and closed.

Dormer

A dormer is a structural element that protrudes from the slope of a roof, typically containing a window. It is used to create additional space or light in an upper level or attic, enhancing both the aesthetic appeal and functionality of the building.

Double-Hung Window

A type of window that consists of two vertically sliding sashes, allowing for both the top and bottom sections to be opened independently. This design enhances ventilation and makes cleaning easier, as the sashes can tilt inward.

Downspout

A downspout is a vertical pipe that directs rainwater from a roof's gutter system down to the ground or drainage system, helping to prevent water damage to the building's foundation and surrounding areas.

Draft

The pressure difference existing between the appliance or any component part and the atmosphere, that causes a continuous flow of air and products of combustion through the gas passages of the appliance to the atmosphere. Induced draft. The pressure difference created by the action of a fan, blower or ejector, that is located between the appliance and the chimney or vent termination. Natural draft. The pressure difference created by a vent or chimney because of its height, and the temperature difference between the flue gases and the atmosphere.

Draft Hood

A device built into an appliance, or a part of the vent connector from an appliance, that is designed to provide for the ready escape of the flue gases from the appliance in the event of no draft, backdraft or stoppage beyond the draft hood; prevent a backdraft from entering the appliance; and neutralize the effect of stack action of the chimney or gas vent on the operation of the appliance.

Draft Regulator

A device that functions to maintain a desired draft in the appliance by automatically reducing the draft to the desired value.

Draft Stop

A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor-ceiling assemblies, roof-ceiling assemblies and attics.

Drain

Any pipe that carries soil and waterborne wastes in a building drainage system.

Drain-Back System

A solar thermal system in which the fluid in the solar collector loop is drained from the collector into a holding tank under prescribed circumstances.

Drainage Fitting

A pipe fitting designed to provide connections in the drainage system that have provisions for establishing the desired slope in the system. These fittings are made from a variety of both metals and plastics. The methods of coupling provide for required slope in the system.

Drop Ceiling

A drop ceiling is a secondary ceiling that is suspended below the main ceiling, typically used to hide ductwork, plumbing, or electrical wiring. It consists of a grid system that holds lightweight panels, allowing for easy access to the space above for maintenance and repairs.

Drywall

A panel made of gypsum plaster pressed between two thick sheets of paper, commonly used to create interior walls and ceilings. It is lightweight, easy to install, and can be finished with paint or wallpaper.

Duct System

A continuous passageway for the transmission of air that, in addition to ducts, includes duct fittings, dampers, plenums, fans and accessory air-handling equipment and appliances.

Ductwork

Ductwork refers to the system of ducts used to transport air throughout a building for heating, ventilation, and air conditioning (HVAC). Properly installed and maintained ductwork ensures efficient airflow, which is essential for maintaining comfortable indoor temperatures and good air quality.

Dwelling

Any building that contains one or two dwelling units used, intended, or designed to be built, used, rented, leased, let or hired out to be occupied, or that are occupied for living purposes.

Dwelling Unit

A single unit providing complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation.

Dwv

Abbreviated term for drain, waste and vent piping as used in common plumbing practice.

E

Easement

A legal right to use someone else's land for a specific purpose, such as accessing utilities or pathways, without owning the land. This can affect property value and usage.

Eaves

The lower edges of a roof that overhang the walls of a building, designed to direct rainwater away from the structure and protect the walls and foundation from water damage.

Effective Opening

The minimum cross-sectional area at the point of water-supply discharge, measured or expressed in terms of diameter of a circle and if the opening is not circular, the diameter of a circle of equivalent cross-sectional area. (This is applicable to air gap.)

Egress

Egress refers to a safe and accessible exit from a building, typically required by building codes to ensure that occupants can escape in case of an emergency. It often includes doors, windows, or other openings that provide a clear path to the outside.

Egress Window

An egress window is a specially designed window that provides a safe exit from a building in case of an emergency. It must meet specific size and accessibility requirements to ensure that occupants can easily escape and that emergency responders can enter.

EIFS

A type of exterior wall system that consists of a synthetic stucco finish applied over insulation board, which is then attached to a water-resistant barrier. EIFS is designed to provide an energy-efficient and aesthetically pleasing exterior, but it can be susceptible to moisture issues if not properly installed or maintained.

Elbow

A pressure pipe fitting designed to provide an exact change in direction of a pipe run. An elbow provides a sharp turn in the flow path.

Electrical Panel

An electrical panel is a metal box that houses circuit breakers or fuses, distributing electricity throughout a building. It serves as the main control point for electrical systems, allowing for the safe management of electrical circuits and providing protection against overloads and short circuits.

Emergency Escape And Rescue Opening

An operable exterior window, door or other similar device that provides for a means of escape and access for rescue in the event of an emergency.

Energy Storage Systems (Ess)

One device or multiple devices, assembled together, capable of storing electrical energy to be supplied at a future time.

Engineered Wood Rim Board

A full-depth structural composite lumber, wood structural panel, structural glued laminated timber or prefabricated wood I-joist member designed to transfer horizontal (shear) and vertical (compression) loads, provide attachment for diaphragm sheathing, siding and exterior deck ledgers and provide lateral support at the ends of floor or roof joists or rafters.

Equipment

Piping, ducts, vents, control devices and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings.

Equivalent Length

For determining friction losses in a piping system, the effect of a particular fitting equal to the friction loss through a straight piping length of the same nominal diameter.

Essentially Nontoxic Transfer Fluids

Fluids having a Gosselin rating of 1, including propylene glycol; mineral oil; polydimethy oil oxane; hydrochlorofluorocarbon, chlorofluorocarbon and hydrofluorocarbon refrigerants; and FDA-approved boiler water additives for steam boilers.

Essentially Toxic Transfer Fluids

Soil, water or graywater and fluids having a Gosselin rating of 2 or more including ethylene glycol, hydrocarbon oils, ammonia refrigerants and hydrazine.

Evaporative Cooler

A device used for reducing air temperature by the process of evaporating water into an airstream.

Excess Air

Air that passes through the combustion chamber and the appliance flue in excess of what is theoretically required for complete combustion.

Exhaust Hood, Full Opening

An exhaust hood with an opening not less than the diameter of the connecting vent.

Expansive Soils

Soils that exhibit volumetric increase or decrease (swelling or shrinking) in response to partial or full wetting or drying under load.

Exterior Insulation And Finish Systems (Eifs)

EIFS are nonstructural, nonload-bearing exterior wall cladding systems that consist of an insulation board attached either adhesively or mechanically, or both, to the substrate; an integrally reinforced base coat; and a textured protective finish coat.

Exterior Insulation And Finish Systems (Eifs) With Drainage

An EIFS that incorporates a means of drainage applied over a water-resistive barrier.

Exterior Wall

An above-grade wall that defines the exterior boundaries of a building. Includes between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable end walls, walls enclosing a mansard roof and basement walls with an average below-grade wall area that is less than 50 percent of the total opaque and nonopaque area of that enclosing side.

Exterior Wall Covering

A material or assembly of materials applied on the exterior side of exterior walls for the purpose of providing a weather-resistive barrier, insulation or for aesthetics, including but not limited to, veneers, siding, exterior insulation and finish systems, architectural trim and embellishments such as cornices, soffits, and fascias.

F

Facing

The wood structural panel facings that form the two outmost rigid layers of the structural insulated panel.

Factory-Built Chimney

A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer's instructions and the conditions of the listing.

Factory-Built Fireplace

A listed and labeled fireplace and chimney system composed of factory-made components, and assembled in the field in accordance with manufacturer's instructions and the conditions of the listing.

Factory-Made Air Duct

A listed and labeled duct manufactured in a factory and assembled in the field in accordance with the manufacturer's instructions and conditions of the listing.

Fascia

A horizontal board that runs along the edge of a roof, often used to support the bottom of the roof's shingles and to provide a finished look. It also helps to protect the roof and the underlying structure from water damage.

Fenestration

Products classified as either vertical fenestration or skylights and sloped glazing, installed in such a manner as to preserve the weather-resistant barrier of the wall or roof in which they are installed. Fenestration includes products with glass or other transparent or translucent materials.

Fenestration, Vertical

Windows that are fixed or movable, opaque doors, glazed doors, glazed block and combination opaque and glazed doors installed in a wall at less than 15 degrees (0.26 rad) from vertical.

Fiber Cement Siding

A type of exterior cladding made from a mixture of cement, sand, and cellulose fibers, fiber cement siding is known for its durability and resistance to rot, insects, and fire. It can mimic the appearance of wood, stucco, or masonry, making it a versatile choice for both residential and commercial buildings.

Fiber-Cement (Backerboard, Siding, Soffit, Trim And Underlayment) Products

Manufactured thin section composites of hydraulic cementitious matrices and discrete nonasbestos fibers.

Fire Door

A fire door is a specialized door designed to resist the spread of fire and smoke between different areas of a building. It is typically made of materials that can withstand high temperatures and is equipped with self-closing mechanisms to ensure it remains closed during a fire, helping to protect escape routes and limit damage.

Fire Wall

A fire wall is a specially designed wall that is constructed to prevent the spread of fire between different sections of a building. It is typically made of non-combustible materials and extends from the foundation to the roof, providing a barrier that helps protect occupants and property by containing flames and smoke within a designated area.

Fire-Retardant-Treated Wood

Wood products that, when impregnated with chemicals by a pressure process or other means during manufacture, exhibit reduced surface burning characteristics and resist propagation of fire. Other means during manufacture. A process where the wood raw material is treated with a fire-retardant formulation while undergoing creation as a finished product. Pressure process. A process for treating wood using an initial vacuum followed by the introduction of pressure above atmospheric.

Fireblocking

Building materials or materials approved for use as fireblocking, installed to resist the free passage of flame to other areas of the building through concealed spaces.

Firebox

A firebox is the part of a fireplace where the fire is contained. It is typically made of fire-resistant materials and is designed to withstand high temperatures while allowing for proper ventilation of smoke and gases.

Fireplace

An assembly consisting of a hearth and fire chamber of noncombustible material and provided with a chimney, for use with solid fuels.

Fireplace Stove

A free-standing, chimney-connected solid-fuel-burning heater designed to be operated with the fire chamber doors in either the open or closed position.

Fireplace Throat

The opening between the top of the firebox and the smoke chamber.

Fixture Branch, Drainage

A drain serving two or more fixtures that discharges into another portion of the drainage system.

Fixture Branch, Water-Supply

A water-supply pipe between the fixture supply and a main water-distribution pipe or fixture group main.

Fixture Drain

The drain from the trap of a fixture to the junction of that drain with any other drain pipe.

Fixture Group, Main

The main water-distribution pipe (or secondary branch) serving a plumbing fixture grouping such as a bath, kitchen or laundry area to which two or more individual fixture branch pipes are connected.

Fixture Supply

The water-supply pipe connecting a fixture or fixture fitting to a fixture branch.

Flame Spread

The propagation of flame over a surface.

Flame Spread Index

A comparative measure, expressed as a dimensionless number, derived from visual measurements of the spread of flame versus time for a material tested in accordance with ASTM E84 or UL 723.

Flexible Air Connector

A conduit for transferring air between an air duct or plenum and an air terminal unit, an air inlet or an air outlet. Such conduit is limited in its use, length and location.

Flight

A continuous run of rectangular treads or winders or combination thereof from one landing to another.

Flood-Level Rim

The edge of the receptor or fixture from which water overflows.

Floor Covering

A floor covering is a material applied over a floor structure to provide a walking surface. Common types include carpet, tile, hardwood, laminate, and vinyl, each offering different aesthetics, durability, and maintenance requirements.

Floor Drain

A plumbing fixture for recess in the floor having a floor-level strainer intended for the purpose of the collection and disposal of wastewater used in cleaning the floor and for the collection and disposal of accidental spillage to the floor.

Floor Furnace

A self-contained furnace suspended from the floor of the space being heated, taking air for combustion from outside such space, and with means for lighting the appliance from such space.

Floor Joist

A floor joist is a horizontal structural component that supports the floor of a building. It spans the space between walls or beams, providing stability and strength to the flooring system. Properly installed floor joists help distribute weight evenly and prevent sagging or bouncing in the floors above.

Flow Pressure

The static pressure reading in the water-supply pipe near the faucet or water outlet while the faucet or water outlet is open and flowing at capacity.

Flue Collar

The portion of a fuel-burning appliance designed for the attachment of a draft hood, vent connector or venting system.

Flue Gases

Products of combustion plus excess air in appliance flues or heat exchangers.

Flue, Appliance

The passages within an appliance through which combustion products pass from the combustion chamber to the flue collar.

Flush Valve

A device located at the bottom of a flush tank that is operated to flush water closets.

Flushometer Tank

A device integrated within an air accumulator vessel that is designed to discharge a predetermined quantity of water to fixtures for flushing purposes.

Flushometer Valve

A flushometer valve is a device that discharges a predetermined quantity of water to fixtures for flushing purposes and is actuated by direct water pressure.

Foam Backer Board

Foam plastic used in siding applications where the foam plastic is a component of the siding.

Foam Plastic Insulation

A plastic that is intentionally expanded by the use of a foaming agent to produce a reduced-density plastic containing voids consisting of open or closed cells distributed throughout the plastic for thermal insulating or acoustic purposes and that has a density less than 20 pounds per cubic foot (320 kg/m3) unless it is used as interior trim.

Foam Plastic Interior Trim

Exposed foam plastic used as picture molds, chair rails, crown moldings, baseboards, handrails, ceiling beams, door trim and window trim and similar decorative or protective materials used in fixed applications.

Footing

A footing is a structural element that supports the foundation of a building, typically made of concrete. It distributes the weight of the structure evenly to prevent settling or shifting, ensuring stability and integrity over time.

Foundation

Foundation settlement is when a building's foundation sinks or shifts unevenly, potentially causing cracks in walls and floors. This can occur due to soil erosion, moisture changes, or inadequate support, leading to structural issues if not addressed.

Framing

Framing is the structural framework of a building, typically made of wood or metal, that supports the walls, roof, and floors. It provides the shape and strength of the structure, allowing for the installation of insulation, drywall, and other finishing materials. Proper framing is essential for the overall stability and safety of a building.

French Drain

A French drain is a type of drainage system that consists of a trench filled with gravel or rock, containing a perforated pipe at the bottom. It is designed to redirect surface water and groundwater away from an area, helping to prevent flooding and water accumulation around foundations.

Fuel Cell Power System, Stationary

A stationary energy generation system that converts the chemical energy of a fuel and oxidant to electric energy (DC or AC electricity) by an electrochemical process. Field-fabricated fuel cell power system. A stationary fuel cell power system that is assembled at the job site and is not a preengineered or prepackaged factory-assembled fuel cell power system. Preengineered fuel cell power system. A stationary fuel cell power system consisting of components and modules that are produced in a factory, and shipped to the job site for assembly. Prepackaged fuel cell power system. A stationary fuel cell power system that is factory assembled as a single, complete unit and shipped as a complete unit for installation at the job site.

Fuel-Piping System

All piping, tubing, valves and fittings used to connect fuel utilization equipment to the point of fuel delivery.

Full-Open Valve

A water control or shutoff component in the water supply system piping that, where adjusted for maximum flow, the flow path through the component's closure member is not a restriction in the component's through-flow area.

Fullway Valve

A valve that in the full open position has an opening cross-sectional area that is not less than 85 percent of the cross-sectional area of the connecting pipe.

Furnace

A vented heating appliance designed or arranged to discharge heated air into a conditioned space or through a duct or ducts.

Fuse

A fuse is a safety device that protects electrical circuits from overloads by breaking the circuit when the current exceeds a certain level, preventing potential damage or fire hazards.

G

Garage

A garage is a covered structure designed to store vehicles, tools, and other equipment. It can be attached to a home or stand alone and often includes features like doors for security and ventilation to prevent moisture buildup.

Garage Door

A garage door is a large door that opens and closes to allow vehicles to enter and exit a garage. It can be operated manually or automatically, often using a remote control, and is designed to provide security and protection for vehicles and stored items.

Garage Door Opener

A device that automatically opens and closes a garage door, typically operated by a remote control or a wall switch. It enhances convenience and security for homeowners by allowing easy access to the garage without manual effort.

Garage Door Spring

A garage door spring is a crucial component that helps lift and lower the garage door. It stores energy when the door is closed and releases it to assist in opening the door, making it easier to operate. There are two main types: torsion springs, which are mounted above the door, and extension springs, which are located on either side. Proper maintenance of these springs is essential for safe and efficient garage door operation.

Garbage Disposal

A garbage disposal is a device installed under a kitchen sink that grinds food waste into small particles, allowing it to be easily washed away through the plumbing system.

Gas Line

A gas line is a pipe that transports natural gas or propane from a supply source to appliances such as stoves, heaters, and water heaters. Proper installation and maintenance are crucial to ensure safety and prevent leaks.

GFCI

A GFCI is a safety device that protects against electrical shock by shutting off power when it detects an imbalance in electrical current. It is commonly installed in areas where water and electricity may come into contact, such as kitchens and bathrooms.

Glass Mat Gypsum Panel

A gypsum panel consisting of a noncombustible core primarily of gypsum, surfaced with glass mat partially or completely embedded in the core.

Glazing Area

The interior surface area of all glazed fenestration, including the area of sash, curbing or other framing elements, that enclose conditioned space. Includes the area of glazed fenestration assemblies in walls bounding conditioned basements.

Grade

The finished ground level adjoining the building at all exterior walls.

Grade Floor Emergency Escape And Rescue Opening

An emergency escape and rescue opening located such that the bottom of the clear opening is not more than 44 inches (1118 mm) above or below the finished ground level adjacent to the opening.

Grade Plane

A reference plane representing the average of the finished ground level adjoining the building at all exterior walls. Where the finished ground level slopes away from the exterior walls, the reference plane shall be established by the lowest points within the area between the building and the lot line or, where the lot line is more than 6 feet (1829 mm) from the building between the structure and a point 6 feet (1829 mm) from the building.

Grading

Grading refers to the process of leveling or sloping the ground around a property to ensure proper drainage and prevent water accumulation near the foundation. Proper grading helps protect the structure from water damage and erosion.

Graywater

Waste discharged from lavatories, bathtubs, showers, clothes washers and laundry trays.

Gridded Water Distribution System

A water distribution system where every water distribution pipe is interconnected so as to provide two or more paths to each fixture supply pipe.

Gross Area Of Exterior Walls

The normal projection of all exterior walls, including the area of all windows and doors installed therein.

Ground-Source Heat Pump Loop System

Piping buried in horizontal or vertical excavations or placed in a body of water for the purpose of transporting heat transfer liquid to and from a heat pump. Included in this definition are closed loop systems in which the liquid is recirculated and open loop systems in which the liquid is drawn from a well or other source.

Grounding

Grounding is the process of connecting electrical systems to the earth, which helps prevent electrical shock and ensures safety by providing a path for excess electricity to dissipate.

Guard

A building component or a system of building components located near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to the lower level.

Guardrail

A guardrail is a safety barrier installed along the edge of elevated surfaces, such as stairs, balconies, or decks, to prevent falls and enhance safety for occupants.

Guestroom

Any room or rooms used or intended to be used by one or more guests for living or sleeping purposes.

Gutter

A gutter is a channel or trough that collects and directs rainwater away from a building's roof, helping to prevent water damage to the structure and its foundation.

Gypsum Board

The generic name for a family of sheet products consisting of a noncombustible core primarily of gypsum with paper surfacing.

Gypsum Panel Product

The general name for a family of sheet products consisting essentially of gypsum.

Gypsum Sheathing

Gypsum panel products specifically manufactured with enhanced water resistance for use as a substrate for exterior surface materials.

Gypsum Wallboard

A gypsum board used primarily as interior surfacing for building structures.

H

Habitable Space

A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.

Handrail

A horizontal or sloping rail intended for grasping by the hand for guidance or support.

Hardscape

Hardscape refers to the non-plant elements of landscaping, such as patios, walkways, retaining walls, and other structures made from materials like stone, concrete, or brick. These features provide functional spaces and enhance the aesthetic appeal of outdoor areas.

Hazardous Location

Any location considered to be a fire hazard for flammable vapors, dust, combustible fibers or other highly combustible substances.

Hearth

A hearth is the floor area in front of a fireplace, typically made of non-combustible materials like brick, stone, or tile, designed to protect the surrounding floor from heat and embers.

Heat Pump

A heat pump is a device that transfers heat from one place to another, often used for heating or cooling buildings. It works by extracting heat from the air, ground, or water and moving it indoors during winter, while in summer, it can reverse the process to cool the space by removing heat from inside and releasing it outside.

Height, Building

The vertical distance from grade plane to the average height of the highest roof surface.

Height, Story

The vertical distance from top to top of two successive tiers of beams or finished floor surfaces; and, for the topmost story, from the top of the floor finish to the top of the ceiling joists or, where there is not a ceiling, to the top of the roof rafters.

Hill

With respect to topographic wind effects, a land surface characterized by strong relief in any horizontal direction.

Homeowners Association

A homeowners association is an organization in a residential community that enforces rules and regulations for the properties within its jurisdiction, manages common areas, and collects fees from homeowners to maintain shared amenities and services.

Horizontal Branch, Drainage

A drain pipe extending laterally from a soil or waste stack or building drain, that receives the discharge from one or more fixture drains.

Horizontal Pipe

Any pipe or fitting that makes an angle of less than 45 degrees (0.79 rad) with the horizontal.

Hot Water

Water at a temperature greater than 120°F (49°C).

Hurricane-Prone Regions

Areas vulnerable to hurricanes, defined as the US Atlantic Ocean and Gulf of Mexico coasts where the ultimate design wind speed, Vult, is greater than 115 miles per hour (51 m/s), and Hawaii, Puerto Rico, Guam, Virgin Islands and America Samoa.

HVAC

Heating, ventilation, and air conditioning (HVAC) systems are essential for maintaining indoor comfort by regulating temperature, humidity, and air quality. These systems include components such as furnaces, air conditioners, heat pumps, and ventilation fans, working together to provide heating in winter and cooling in summer. Proper maintenance of HVAC systems is crucial for energy efficiency and longevity.

Hydrogen-Generating Appliance

A self-contained package or factory-matched packages of integrated systems for generating gaseous hydrogen. Hydrogen-generating appliances utilize electrolysis, reformation, chemical or other processes to generate hydrogen.

I

Ignition Source

A flame, spark or hot surface capable of igniting flammable vapors or fumes. Such sources include appliance burners, burner ignitions and electrical switching devices.

Impact Protective System

Construction that has been shown by testing to withstand the impact of test missiles and that is applied, attached, or locked over exterior glazing.

Indirect System

A solar thermal system in which the gas or liquid in the solar collector loop circulates between the solar collector and a heat exchanger and such gas or liquid is not drained from the system or supplied to the load during normal operation.

Indirect Waste Pipe

A waste pipe that discharges into the drainage system through an air gap into a trap, fixture or receptor.

Individual Sewage Disposal System

A system for disposal of sewage by means of a septic tank or mechanical treatment, designed for use apart from a public sewer to serve a single establishment or building.

Individual Vent

A pipe installed to vent a single fixture drain that connects with the vent system above or terminates independently outside the building.

Individual Water Supply

A supply other than an approved public water supply that serves one or more families.

Insulated Siding

A type of continuous insulation, with manufacturer-installed insulating material as an integral part of the cladding product, having a minimum R-value of R-2.

Insulated Vinyl Siding

A vinyl cladding product, with manufacturer-installed foam plastic insulating material as an integral part of the cladding product, having a thermal resistance of not less than R-2.

Insulating Concrete Form (Icf)

A concrete forming system using stay-in-place forms of rigid foam plastic insulation, a hybrid of cement and foam insulation, a hybrid of cement and wood chips, or other insulating material for constructing cast-in-place concrete walls.

Insulating Sheathing

A rigid panel or board insulation material having a thermal resistance of not less than R-2 of the core material with properties suitable for use on walls, floors, roofs or foundations.

Insulation

A material used to reduce heat transfer between the interior and exterior of a building, helping to maintain comfortable temperatures and improve energy efficiency. Insulation can be found in various forms, such as batts, rolls, foam boards, or spray foam, and is commonly installed in walls, attics, and floors.

J

Joist

A horizontal structural element that supports a ceiling or floor, typically spanning between walls or beams. Joists are crucial for distributing weight and providing stability to the structure above.

K

Kitchen

An area used, or designated to be used, for the preparation of food.

L

Label

An identification applied on a product by the manufacturer that contains the name of the manufacturer, the function and performance characteristics of the product or material, and the name and identification of an approved agency and that indicates that the representative sample of the product or material has been tested and evaluated by an approved agency.

Labeled

Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, approved agency or other organization concerned with product evaluation that maintains periodic inspection of the production of such labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose.

Lead Paint

A toxic substance found in many homes built before 1978, lead paint can pose serious health risks, especially to young children and pregnant women. It can deteriorate over time, creating lead dust or chips that can be ingested or inhaled, leading to lead poisoning. Proper testing and remediation are essential for safety.

Light-Frame Construction

Construction whose vertical and horizontal structural elements are primarily formed by a system of repetitive wood or cold-formed steel framing members.

Listed

Equipment, materials, products or services included in a list published by an organization acceptable to the code official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the equipment, material, product or service meets identified standards or has been tested and found suitable for a specified purpose.

Live Loads

Those loads produced by the use and occupancy of the building or other structure and do not include construction or environmental loads such as wind load, snow load, rain load, earthquake load, flood load or dead load.

Living Space

Space within a building utilized for living, sleeping, eating, cooking, bathing, washing and sanitation purposes. Garages, greenhouses, closets, storage spaces, and utility spaces are not considered living space.

Load-Bearing Wall

A load-bearing wall is a structural wall that supports the weight of the roof, floors, and other elements above it. Removing or altering this type of wall without proper support can compromise the building's stability and safety.

Local Exhaust

An exhaust system that uses one or more fans to exhaust air from a specific room or rooms within a dwelling.

Locking-Type Tamper-Resistant Cap

A cap designed to be unlocked by a specially designed tool or key to prevent removal of the cap by means of hand-loosening or by commonly available tools.

Lodging House

A one-family dwelling where one or more occupants are primarily permanent in nature, and rent is paid for guestrooms.

Lot

A measured portion or parcel of land considered as a unit having fixed boundaries.

Lot Line

The line that bounds a plot of ground described as a lot in the title to the property.

Low-E Glass

Low-E glass is a type of energy-efficient window glass that has a special coating to reflect infrared light, helping to keep heat inside during winter and outside during summer. This can lead to reduced energy costs and improved comfort in a building.

M

Macerating Toilet Systems

A system comprised of a sump with macerating pump and with connections for a water closet and other plumbing fixtures, that is designed to accept, grind and pump wastes to an approved point of discharge.

Main

The principal pipe artery to which branches may be connected.

Main Shutoff Valve

A main shutoff valve is a critical component in a plumbing system that allows homeowners to control the flow of water into their property. It is typically located near where the water line enters the building and can be turned off in case of a plumbing emergency or when repairs are needed.

Manifold Water Distribution Systems

A fabricated piping arrangement in which a large supply main is fitted with multiple branches in close proximity in which water is distributed separately to fixtures from each branch.

Mantel

A mantel is a decorative framework around a fireplace, often extending to form a shelf above the fireplace opening. It serves both aesthetic and functional purposes, providing a place to display items and helping to protect the surrounding wall from heat.

Manufacturer'S Designation

An identification applied on a product by the manufacturer indicating that a product or material complies with a specified standard or set of rules.

Manufacturer'S Installation Instructions

Printed instructions included with equipment as part of the conditions of their listing and labeling.

Mark

An identification applied on a product by the manufacturer indicating the name of the manufacturer and the function of a product or material.

Masonry Chimney

A field-constructed chimney composed of solid masonry units, bricks, stones or concrete.

Masonry Fireplace

A field-constructed fireplace composed of solid masonry units, bricks, stones or concrete.

Masonry Heater

A masonry heater is a solid fuel burning heating appliance constructed predominantly of concrete or solid masonry having a mass of not less than 1,100 pounds (500 kg), excluding the chimney and foundation. It is designed to absorb and store a substantial portion of heat from a fire built in the firebox by routing exhaust gases through internal heat exchange channels in which the flow path downstream of the firebox includes not less than one 180-degree (3.14-rad) change in flow direction before entering the chimney and that deliver heat by radiation through the masonry surface of the heater.

Masonry, Solid

Masonry consisting of solid masonry units laid contiguously with the joints between the units filled with mortar.

Mean Roof Height

The average of the roof eave height and the height to the highest point on the roof surface, except that eave height shall be used for roof angle of less than or equal to 10 degrees (0.18 rad).

Mechanical Draft System

A venting system designed to remove flue or vent gases by mechanical means, that consists of an induced draft portion under nonpositive static pressure or a forced draft portion under positive static pressure.

Mechanical Exhaust System

A system for removing air from a room or space by mechanical means.

Membrane Roofing

Membrane roofing is a type of roofing system that consists of a continuous layer of material, typically made from synthetic rubber, thermoplastic, or modified bitumen, which is applied to flat or low-slope roofs. This system is designed to provide a waterproof barrier, protecting the building from leaks and water damage.

Metal Roof Panel

An interlocking metal sheet having an installed weather exposure of not less than 3 square feet (0.28 m2) per sheet.

Metal Roof Shingle

An interlocking metal sheet having an installed weather exposure less than 3 square feet (0.28 m2) per sheet.

Mezzanine

An intermediate level or levels between the floor and ceiling of any story.

Microwave Oven

A microwave oven is a kitchen appliance that uses electromagnetic radiation to heat and cook food quickly. It operates by agitating water molecules in the food, generating heat through friction.

Modified Bitumen Roof Covering

One or more layers of polymer modified asphalt sheets. The sheet materials shall be fully adhered or mechanically attached to the substrate or held in place with an approved ballast layer.

Mold

Mold is a type of fungus that grows in damp, warm, and humid environments. It can appear as a fuzzy or discolored patch on surfaces and can cause health issues, including allergies and respiratory problems, if not properly managed.

Mulch

A protective layer of material, often made from organic materials like wood chips or bark, spread over soil to retain moisture, suppress weeds, and improve the appearance of garden beds and landscaping.

Multiple-Station Smoke Alarm

Two or more single-station alarm devices that are capable of interconnection such that actuation of one causes all integral or separate audible alarms to operate.

N

Nailable Substrate

A product or material such as framing, sheathing or furring, composed of wood or wood-based materials, or other materials and fasteners providing equivalent fastener withdrawal resistance.

Natural Draft System

A venting system designed to remove flue or vent gases under nonpositive static vent pressure entirely by natural draft.

Naturally Durable Wood

The heartwood of the following species with the exception that an occasional piece with corner sapwood is permitted if 90 percent or more of the width of each side on which it occurs is heartwood.

Nosing

The leading edge of treads of stairs and of landings at the top of stairway flights.

O

Occupied Space

The total area of all buildings or structures on any lot or parcel of ground projected on a horizontal plane.

Offset

A combination of fittings that makes two changes in direction, bringing one section of the pipe out of line and into a line parallel with the other section.

On-Site Nonpotable Water Reuse Systems

Water systems for the collection, treatment, storage, distribution, and reuse of nonpotable water generated on site, including but not limited to graywater systems. This definition does not include rainwater harvesting systems.

Outlet

An outlet is a point in an electrical system where electrical devices can be connected to receive power. It typically consists of a socket that allows for the insertion of plugs from appliances or equipment.

Oven/Range (Stove)

An oven/range is a kitchen appliance used for cooking food, typically consisting of a stove top for boiling and frying, and an oven for baking and roasting.

Owner

Any person, agent, firm or corporation having a legal or equitable interest in the property.

P

P-Trap

A P-Trap is a plumbing fixture that holds a small amount of water to create a seal, preventing sewer gases from entering a building. It is typically found under sinks, bathtubs, and other drainage systems.

Pan Flashing

Corrosion-resistant flashing at the base of an opening that is integrated into the building exterior wall to direct water to the exterior and is premanufactured, fabricated, formed or applied at the job site.

Panel Thickness

Thickness of core plus two layers of structural wood panel facings.

Partition Wall

A partition wall is a non-load-bearing wall that divides spaces within a building, providing privacy or separating different areas without supporting the structure above.

Party Wall

A party wall is a shared wall that separates two adjacent properties, typically found in semi-detached or terraced buildings. It is jointly owned by the property owners on either side and is subject to specific legal rights and responsibilities regarding maintenance and alterations.

Pellet Fuel-Burning Appliance

A closed combustion, vented appliance equipped with a fuel feed mechanism for burning processed pellets of solid fuel of a specified size and composition.

Pellet Vent

A vent listed and labeled for use with a listed pellet fuel-burning appliance.

Permit

An official document or certificate issued by the building official that authorizes performance of a specified activity.

Photovoltaic Module

A complete, environmentally protected unit consisting of solar cells, optics and other components, exclusive of a tracker, designed to generate DC power where exposed to sunlight.

Photovoltaic Panel

A collection of photovoltaic modules mechanically fastened together, wired, and designed to provide a field-installable unit.

Photovoltaic Panel System

A system that incorporates discrete photovoltaic panels that convert solar radiation into electricity, including rack support systems.

Photovoltaic Shingles

A roof covering that resembles shingles and that incorporates photovoltaic modules.

Picture Window

A large, fixed window that does not open, designed to provide an unobstructed view and allow maximum natural light into a room. Picture windows are often used in living rooms or areas where a scenic view is available, enhancing the aesthetic appeal of the space.

Pier and Beam Foundation

A type of foundation consisting of a series of vertical piers that support beams, which in turn hold up the structure above. This design allows for ventilation and access to plumbing and electrical systems beneath the building, making it easier to maintain and repair.

Pile Foundation

A type of foundation that consists of vertical columns or piles driven deep into the ground to support a structure. This method is often used in areas with weak soil or where the load-bearing capacity of the surface soil is insufficient. Pile foundations help distribute the weight of the building evenly and reduce the risk of settling or shifting.

Plaster

A material made from gypsum, water, and additives, used for coating walls and ceilings to create a smooth surface. It can also be used for decorative elements and is known for its fire-resistant properties.

Plastic Composite

A generic designation that refers to wood-plastic composites and plastic lumber.

Platform Construction

A method of construction by which floor framing bears on load bearing walls that are not continuous through the story levels or floor framing.

Plenum

A chamber that forms part of an air-circulation system other than the occupied space being conditioned.

Plumbing Appliance

An energized household appliance with plumbing connections, such as a dishwasher, food waste disposer, clothes washer or water heater.

Plumbing Appurtenance

A device or assembly that is an adjunct to the basic plumbing system and does not demand additional water supply or add any discharge load to the system. It is presumed that it performs some useful function in the operation, maintenance, servicing, economy or safety of the plumbing system. Examples include filters, relief valves and aerators.

Plumbing Fixture

A receptacle or device that is connected to a water supply system or discharges to a drainage system or both. Such receptacles or devices require a supply of water; or discharge liquid waste or liquidborne solid waste; or require a supply of water and discharge waste to a drainage system.

Plumbing Systems

Includes the water distribution pipes; plumbing fixtures and traps; water-treating or water-using equipment; soil, waste and vent pipes; and building drains; in addition to their respective connections, devices and appurtenances within a structure or premises; and the water service, building sewer and building storm sewer serving such structure or premises.

Polypropylene Siding

A shaped material, made principally from polypropylene homopolymer, or copolymer, that in some cases contains fillers or reinforcements, that is used to clad exterior walls or buildings.

Popcorn Ceiling

A textured ceiling finish that resembles popcorn, created by spraying a mixture of paint and a textured material. This style was popular in the mid-20th century for its ability to hide imperfections and reduce noise, but it can be difficult to clean and may contain asbestos in older homes.

Porch

A porch is a covered structure attached to the entrance of a building, typically featuring a roof and open sides. It serves as a transitional space between the outdoors and indoors, providing a sheltered area for relaxation or socializing.

Portable-Fuel-Cell Appliance

A fuel cell generator of electricity that is not fixed in place. A portable-fuel-cell appliance utilizes a cord and plug connection to a grid-isolated load and has an integral fuel supply.

Positive Roof Drainage

The drainage condition in which consideration has been made for the loading deflections of the roof deck, and additional slope has been provided to ensure drainage of the roof within 48 hours of precipitation.

Potable Water

Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming in bacteriological and chemical quality to the requirements of the public health authority having jurisdiction.

Precast Concrete

A structural concrete element cast elsewhere than its final position in the structure.

Precast Concrete Foundation Walls

Preengineered, precast concrete wall panels that are designed to withstand specified stresses and used to build below-grade foundations.

Press-Connect Joint

A permanent mechanical joint incorporating an elastomeric seal or an elastomeric seal and corrosion-resistant grip or bite ring. The joint is made with a pressing tool and jaw or ring approved by the fitting manufacturer.

Pressure Regulator

A pressure regulator is a device that controls the pressure of water or gas in a plumbing or gas system, ensuring that it remains at a safe and consistent level to prevent damage to pipes and appliances.

Pressure-Relief Valve

A pressure-actuated valve held closed by a spring or other means and designed to automatically relieve pressure at the pressure at which it is set.

Public Sewer

A common sewer directly controlled by public authority.

Public Water Main

A water-supply pipe for public use controlled by public authority.

Public Way

Any street, alley or other parcel of land open to the outside air leading to a public street, that has been deeded, dedicated or otherwise permanently appropriated to the public for public use and that has a clear width and height of not less than 10 feet (3048 mm).

Purge

To clear of air, gas or other foreign substances.

Push-Fit Fitting

A mechanical fitting that joins pipes or tubes and achieves a seal by mating the pipe or tube into the fitting.

Q

Quick-Closing Valve

A valve or faucet that closes automatically where released manually or controlled by mechanical means for fast-action closing.

R

R-Value

R-Value is a measure of thermal resistance used to determine how well a building material insulates against heat flow. The higher the R-Value, the better the material is at preventing heat loss or gain, which can lead to improved energy efficiency and comfort in a property.

Rafter

A rafter is a structural component of a roof that supports the roof's weight and helps shape its structure. Rafters are typically made of wood or metal and are installed at an angle from the ridge of the roof down to the eaves, forming the framework that holds up the roofing material.

Ramp

A walking surface that has a running slope steeper than 1 unit vertical in 20 units horizontal (5-percent slope).

Range Hood

A range hood is a device installed above a stove or cooktop that helps to ventilate cooking odors, smoke, and steam by drawing air through filters and expelling it outside or recirculating it back into the kitchen.

Ready Access (To)

That which enables a device, appliance or equipment to be directly reached, without requiring the removal or movement of any panel, door or similar obstruction.

Receptor

A fixture or device that receives the discharge from indirect waste pipes.

Reclaimed Water

Nonpotable water that has been derived from the treatment of wastewater by a facility or system licensed or permitted to produce water meeting the jurisdiction's water requirements for its intended uses. Also known as "recycled water."

Refrigerant

A substance used to produce refrigeration by its expansion or evaporation.

Refrigerant Compressor

A specific machine, with or without accessories, for compressing a given refrigerant vapor.

Refrigerating System

A combination of interconnected parts forming a closed circuit in which refrigerant is circulated for the purpose of extracting, then rejecting, heat. A direct refrigerating system is one in which the evaporator or condenser of the refrigerating system is in direct contact with the air or other substances to be cooled or heated. An indirect refrigerating system is one in which a secondary coolant cooled or heated by the refrigerating system is circulated to the air or other substance to be cooled or heated.

Refrigerator

A refrigerator is an appliance used to keep food and beverages cold by removing heat from the interior, typically using a refrigeration cycle. It helps preserve perishable items and maintain their freshness for longer periods.

Registered Design Professional

An individual who is registered or licensed to practice their respective design profession as defined by the statutory requirements of the professional registration laws of the state or jurisdiction in which the project is to be constructed.

Relief Valve, Vacuum

A device to prevent excessive buildup of vacuum in a pressure vessel.

Repair

The reconstruction, replacement or renewal of any part of an existing building for the purpose of its maintenance or to correct damage.

Reroofing

The process of recovering or replacing an existing roof covering.

Retaining Wall

A retaining wall is a structure designed to hold back soil and prevent erosion on sloped land. It provides support to vertical or near-vertical grade changes, helping to create level areas for landscaping, patios, or building foundations.

Return Air

Air removed from an approved conditioned space or location and recirculated or exhausted.

Ridge

The ridge is the highest point of a roof where two sloping sides meet, often serving as a structural element that helps to shed water and snow. It is crucial for maintaining the roof's integrity and preventing leaks.

Ridge Vent

A ridge vent is a type of ventilation system installed along the peak of a roof, allowing hot air and moisture to escape from the attic. This helps maintain a balanced airflow, reducing the risk of mold growth and improving energy efficiency in the building.

Riser (Plumbing)

A water pipe that extends vertically one full story or more to convey water to branches or to a group of fixtures.

Riser (Stair)

The vertical component of a step or stair.

Roof Assembly

A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly can include an underlayment, thermal barrier, ignition barrier, insulation or a vapor retarder.

Roof Coating

A fluid-applied, adhered coating used for roof maintenance or roof repair, or as a component of a roof covering system or roof assembly.

Roof Covering

The covering applied to the roof deck for weather resistance, fire classification or appearance.

Roof Deck

The flat or sloped surface not including its supporting members or vertical supports.

Roof Flashing

A protective barrier installed at joints and seams on a roof to prevent water leakage. It directs water away from critical areas, such as chimneys, vents, and walls, ensuring the roof remains watertight and reducing the risk of damage from moisture intrusion.

Roof Recover

The process of installing an additional roof covering over an existing roof covering without removing the existing roof covering.

Roof Repair

Reconstruction or renewal of any part of an existing roof for the purposes of its maintenance.

Roof Replacement

The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.

Rooftop Unit

A rooftop unit is a type of heating, ventilation, and air conditioning (HVAC) system that is installed on the roof of a building. It is designed to provide climate control for the entire building, often used in commercial properties, and can include both heating and cooling functions in a single unit.

Room Heater

A free-standing heating appliance installed in the space being heated and not connected to ducts.

Rough-In

The installation of the parts of the plumbing system that must be completed prior to the installation of fixtures. This includes DWV, water supply and built-in fixture supports.

Running Bond

The placement of masonry units such that head joints in successive courses are horizontally offset not less than one-quarter the unit length.

S

Sanitary Sewer

A sewer that carries sewage and excludes storm, surface and groundwater.

Scupper

An opening in a wall or parapet that allows water to drain from a roof.

Seismic Design Category (Sdc)

A classification assigned to a structure based on its occupancy category and the severity of the design earthquake ground motion at the site.

Septic System

A septic system is an underground wastewater treatment system that collects and treats sewage from a home or building. It typically consists of a septic tank, where solids settle and are broken down, and a drain field, where treated effluent is dispersed into the soil. Proper maintenance is essential to prevent backups and ensure effective operation.

Septic Tank

A watertight receptor that receives the discharge of a building sanitary drainage system and is constructed so as to separate solids from the liquid, digest organic matter through a period of detention, and allow the liquids to discharge into the soil outside of the tank through a system of open joint or perforated piping or a seepage pit.

Sewage

Any liquid waste containing animal matter, vegetable matter or other impurity in suspension or solution.

Sewage Pump

A permanently installed mechanical device for removing sewage or liquid waste from a sump.

Sewer Line

A sewer line is a pipe that carries wastewater and sewage from a building to a municipal sewer system or a septic tank. Proper functioning of the sewer line is crucial to prevent backups and maintain sanitation.

Sheathing

Sheathing is a layer of material, typically plywood or oriented strand board (OSB), that is applied to the exterior of a building's frame. It provides structural support, helps to insulate the building, and serves as a base for exterior finishes like siding or roofing.

Shingle Fashion

A method of installing roof or wall coverings, water-resistive barriers, flashing or other building components such that upper layers of material are placed overlapping lower layers of material to provide drainage and protect against water intrusion at unsealed penetrations and joints or in combination with sealed joints.

Single-Ply Membrane

A roofing membrane that is field applied using one layer of membrane material (either homogeneous or composite) rather than multiple layers.

Single-Station Smoke Alarm

An assembly incorporating the detector, control equipment and alarm sounding device in one unit that is operated from a power supply either in the unit or obtained at the point of installation.

Skylight

A skylight is a window installed in a roof or ceiling that allows natural light to enter a space, enhancing illumination and creating a more open atmosphere.

Skylight, Unit

A factory assembled, glazed fenestration unit, containing one panel of glazing material, that allows for natural daylighting through an opening in the roof assembly while preserving the weather-resistant barrier of the roof.

Skylights And Sloped Glazing

Glass or other transparent or translucent glazing material installed at a slope of 15 degrees (0.26 rad) or more from vertical. Unit skylights, tubular daylighting devices and glazing materials in solariums, sunrooms, roofs and sloped walls are included in this definition.

Slab-on-Grade

A type of foundation where a concrete slab is poured directly on the ground, providing a solid base for the structure. This method is often used in areas with minimal frost and is cost-effective, but it may be susceptible to cracking due to soil movement or moisture changes.

Sleeping Room

Any room used or intended to be used for sleeping purposes.

Sleeping Unit

A single unit that provides rooms or spaces for one or more persons, includes permanent provisions for sleeping and can include provisions for living, eating and either sanitation or kitchen facilities but not both. Such rooms and spaces that are also part of a dwelling unit are not sleeping units.

Sliding Window

A sliding window is a type of window that opens horizontally by sliding along a track, allowing for easy ventilation and access to natural light.

Slip Joint

A mechanical-type joint used primarily on fixture traps. The joint tightness is obtained by compressing a friction-type washer such as rubber, nylon, neoprene, lead or special packing material against the pipe by the tightening of a (slip) nut.

Slope

The fall (pitch) of a line of pipe in reference to a horizontal plane. In drainage, the slope is expressed as the fall in units vertical per units horizontal (percent) for a length of pipe.

Smoke Detector

A device that detects smoke as an indicator of fire, typically emitting an alarm to alert occupants. It is essential for enhancing safety in homes and commercial properties by providing early warning of potential fire hazards.

Smoke-Developed Index

A comparative measure, expressed as a dimensionless number, derived from measurements of smoke obscuration versus time for a material tested in accordance with ASTM E84 or UL 723.

Soffit

A soffit is the underside of a roof overhang or eave, often used to conceal structural elements and provide ventilation to the attic space. It can also enhance the aesthetic appeal of a building's exterior.

Soffit Vent

A soffit vent is a type of ventilation installed in the soffit area of a roof, allowing air to flow into the attic space. This helps to regulate temperature and moisture levels, preventing issues like mold growth and ice dam formation. Proper ventilation is essential for maintaining the health of a roof and the overall structure of a building.

Softscape

Softscape refers to the living elements of landscaping, such as plants, trees, shrubs, and flowers, as opposed to hardscape, which includes non-living features like patios, walkways, and walls. Softscape plays a crucial role in enhancing the aesthetic appeal of a property and can also contribute to environmental benefits like improved air quality and habitat for wildlife.

Soil Stack Or Pipe

A pipe that conveys sewage containing fecal material.

Solar Energy System

A system that converts solar radiation to usable energy, including photovoltaic panel systems and solar thermal systems.

Solar Thermal Collector

Components in a solar thermal system that collect and convert solar radiation to thermal energy.

Solar Thermal System

A system that converts solar radiation to thermal energy for use in heating or cooling.

Solid Masonry

Load-bearing or nonload-bearing construction using masonry units where the net cross-sectional area of each unit in any plane parallel to the bearing surface is not less than 75 percent of its gross cross-sectional area. Solid masonry units shall conform to ASTM C55, C62, C73, C145 or C216.

Spline

A strip of wood structural panel cut from the same material used for the panel facings, used to connect two structural insulated panels. The strip (spline) fits into a groove cut into the vertical edges of the two structural insulated panels to be joined. Splines are used behind each facing of the structural insulated panels being connected as shown in Figure R610.8.

Sprinkler System

A sprinkler system is an irrigation method that uses a network of pipes and sprinkler heads to distribute water evenly across a landscape or garden, ensuring proper hydration for plants and grass.

Stack

Any main vertical DWV line, including offsets, that extends one or more stories as directly as possible to its vent terminal.

Stack Bond

The placement of masonry units in a bond pattern is such that head joints in successive courses are vertically aligned.

Stack Vent

The extension of soil or waste stack above the highest horizontal drain connected.

Stair

A change in elevation, consisting of one or more risers.

Staircase

A staircase is a set of steps that allows people to move between different levels of a building. It typically consists of treads (the flat parts you step on) and risers (the vertical parts between each tread), and may include handrails for safety.

Stairway

One or more flights of stairs, either interior or exterior, with the necessary landings and connecting platforms to form a continuous and uninterrupted passage from one level to another.

Stairway, Spiral

A stairway with a plan view of closed circular form and uniform section-shaped treads radiating from a minimum-diameter circle.

Standard Truss

Any construction that does not permit the roof-ceiling insulation to achieve the required R-value over the exterior walls.

Stem Wall

A stem wall is a vertical wall that extends from the foundation of a building to support the structure above, often used to elevate the building above ground level and protect it from moisture and flooding.

Stone Veneer

A decorative layer of thin stone applied to the exterior of a building, providing the appearance of solid stone without the weight and cost. It is often used to enhance aesthetic appeal and can be made from natural or manufactured stones.

Storm Sewer, Drain

A pipe used for conveying rainwater, surface water, subsurface water and similar liquid waste.

Storm Shelter

A building, structure or portion thereof, constructed in accordance with ICC 500 and designated for use during a severe wind storm event, such as a hurricane or tornado.

Story

That portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above.

Story Above Grade Plane

Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is either of the following: 1. More than 6 feet (1829 mm) above grade plane. 2. More than 12 feet (3658 mm) above the finished ground level at any point.

Structural Insulated Panel (Sip)

A structural sandwich panel that consists of a lightweight foam plastic core securely laminated between two thin, rigid wood structural panel facings.

Structure

That which is built or constructed.

Stucco

A type of exterior finish made from a mixture of cement, sand, and lime, applied to walls to create a durable and weather-resistant surface. It can be textured or smooth and is often used for aesthetic purposes as well as protection against moisture and pests.

Subfloor

A subfloor is the layer of flooring that is installed directly on top of the floor joists and beneath the finished floor covering. It provides structural support and stability to the floor, helping to distribute weight and prevent sagging or bouncing.

Subsoil Drain

A drain that collects subsurface water or seepage water and conveys such water to a place of disposal.

Sump

A tank or pit that receives sewage or waste, located below the normal grade of the gravity system and that must be emptied by mechanical means.

Sump Pump

A sump pump is a device installed in the lowest part of a basement or crawl space that helps to remove accumulated water. It typically consists of a pump and a pit, or sump basin, where water collects. When the water level rises, the pump activates to discharge the water away from the property, preventing flooding and water damage.

Sunroom

A one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of the structure's exterior walls and roof.

Supply Air

Air delivered to a conditioned space through ducts or plenums from the heat exchanger of a heating, cooling or ventilating system.

Supports

Devices for supporting, hanging and securing pipes, fixtures and equipment.

Swale

A swale is a shallow, vegetated channel designed to manage water runoff, promote drainage, and reduce erosion. It helps direct water away from structures and can improve landscape aesthetics while supporting plant growth.

Sweep

A drainage fitting designed to provide a change in direction of a drain pipe of less than the angle specified by the amount necessary to establish the desired slope of the line. Sweeps provide a longer turning radius than bends and a less turbulent flow pattern.

T

Temperature- And Pressure-Relief (T And P) Valve

A combination relief valve designed to function as both a temperature-relief and pressure-relief valve.

Temperature-Relief Valve

A temperature-actuated valve designed to discharge automatically at the temperature at which it is set.

Thermostat

A device that regulates the temperature of a heating or cooling system by turning it on or off based on the desired temperature set by the user.

Threshold

A threshold is a strip of material that forms the bottom of a doorway, serving as a transition between two different flooring types or spaces. It helps to prevent drafts, water, and dirt from entering a room while providing a finished look to the doorway.

Trap

A fitting, either separate or built into a fixture, that provides a liquid seal to prevent the emission of sewer gases without materially affecting the flow of sewage or wastewater through it.

Trap Arm

That portion of a fixture drain between a trap weir and the vent fitting.

Trap Primer

A device or system of piping to maintain a water seal in a trap, typically installed where infrequent use of the trap would result in evaporation of the trap seal, such as floor drains.

Trap Seal

The trap seal is the maximum vertical depth of liquid that a trap will retain, measured between the crown weir and the top of the dip of the trap.

Tray Ceiling

A tray ceiling is a type of ceiling design that features a recessed area in the center, creating a step-like effect. This architectural detail adds depth and visual interest to a room, often enhancing its overall aesthetic appeal.

Trim

Picture molds, chair rails, baseboards, handrails, door and window frames, and similar decorative or protective materials used in fixed applications.

Truss

A truss is a structural framework typically made of wood or metal, designed to support a roof or bridge. It consists of interconnected elements that form triangular shapes, providing strength and stability while allowing for open spaces below.

Truss Design Drawing

The graphic depiction of an individual truss, that describes the design and physical characteristics of the truss.

Tubular Daylighting Device (Tdd)

A nonoperable fenestration unit primarily designed to transmit daylight from a roof surface to an interior ceiling via a tubular conduit. The basic unit consists of an exterior glazed weathering surface, a light-transmitting tube with a reflective interior surface, and an interior-sealing device such as a translucent ceiling panel. The unit may be factory assembled, or field assembled from a manufactured kit.

Type L Vent

A listed and labeled vent conforming to UL 641 for venting oil-burning appliances listed for use with Type L vents or with gas appliances listed for use with Type B vents.

U

Underlayment

One or more layers of felt, sheathing paper, nonbituminous saturated felt, or other approved material over which a roof covering, with a slope of 2 units vertical in 12 units horizontal (17-percent slope) or greater, is applied.

V

Vacuum Breaker

A device that prevents backsiphonage of water by admitting atmospheric pressure through ports to the discharge side of the device.

Valley

A valley is a V-shaped channel formed by the intersection of two sloping roof surfaces, designed to direct water runoff to the gutters. Proper drainage in valleys is crucial to prevent water pooling and potential leaks.

Vapor Barrier

A vapor barrier is a material used to prevent moisture from passing through walls, floors, and ceilings, helping to protect structures from water damage and mold growth.

Vapor Diffusion Port

An assembly constructed or installed within a roof assembly at an opening in the roof deck to convey water vapor from an unvented attic to the outside atmosphere.

Vapor Permeable

The property of having a moisture vapor permeance rating of 5 perms (2.9 × 10-10kg/Pa × s × m2) or greater, where tested in accordance with Procedure A or Procedure B of ASTM E96. A vapor permeable material permits the passage of moisture vapor.

Vapor Retarder Class

A measure of the ability of a material or assembly to limit the amount of moisture that passes through that material or assembly. Vapor retarder class shall be defined using the desiccant method with Procedure A of ASTM E96 as follows: Class I: ≤ 0.1 perm rating Class II: > 0.1 to ≤ 1.0 perm rating Class III: > 1.0 to ≤ 10 perm rating

Vent

A passageway for conveying flue gases from fuel-fired appliances, or their vent connectors, to the outside atmosphere.

Vent Connector

That portion of a venting system that connects the flue collar or draft hood of an appliance to a vent.

Vent Damper Device, Automatic

A device intended for installation in the venting system, in the outlet of an individual, automatically operated fuel-burning appliance and that is designed to open the venting system automatically where the appliance is in operation and to close off the venting system automatically where the appliance is in a standby or shutdown condition.

Vent Gases

Products of combustion from fuel-burning appliances, plus excess air and dilution air, in the venting system above the draft hood or draft regulator.

Vent Stack

A vertical vent pipe installed to provide circulation of air to and from the drainage system and that extends through one or more stories.

Vent System

Piping installed to equalize pneumatic pressure in a drainage system to prevent trap seal loss or blowback due to siphonage or back pressure.

Ventilation

The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, any space.

Venting

Removal of combustion products to the outdoors.

Venting System

A continuous open passageway from the flue collar of an appliance to the outside atmosphere for the purpose of removing flue or vent gases. A venting system is usually composed of a vent or a chimney and vent connector, if used, assembled to form the open passageway.

Vertical Pipe

Any pipe or fitting that makes an angle of 45 degrees (0.79 rad) or more with the horizontal.

Vertical Rebar

Vertical rebar refers to steel bars that are installed vertically within concrete structures, such as walls or columns, to provide reinforcement and increase the structure's strength and stability.

Vinyl Siding

A shaped material, made principally from rigid polyvinyl chloride (PVC), that is used to cover exterior walls of buildings.

W

Wainscoting

A decorative wall treatment that typically consists of wooden panels installed along the lower portion of a wall, often used to enhance the aesthetic appeal of a room while also providing protection against wear and tear.

Wall, Retaining

A wall not laterally supported at the top, that resists lateral soil load and other imposed loads.

Walls

Load-bearing wall. A wall supporting any vertical load in addition to its own weight. Nonbearing wall. A wall which does not support vertical loads other than its own weight.

Washing Machine (Washer)

A washing machine is an appliance used for cleaning laundry, such as clothes and linens, by agitating them in water mixed with detergent. It typically has various settings for different fabric types and soil levels, allowing users to customize the wash cycle for optimal cleaning results.

Waste

Liquidborne waste that is free of fecal matter.

Waste Pipe Or Stack

Piping that conveys only liquid sewage not containing fecal material.

Waste Receptor

A floor sink, standpipe, hub drain or a floor drain that receives the discharge of one or more indirect waste pipes.

Water Distribution System

Piping that conveys water from the service to the plumbing fixtures, appliances, appurtenances, equipment, devices or other systems served, including fittings and control valves.

Water Heater

Any heating appliance or equipment that heats potable water and supplies such water to the potable hot water distribution system.

Water Main

A water supply pipe for public use.

Water Outlet

A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of the supply system.

Water Service Pipe

The outside pipe from the water main or other source of potable water supply to the water distribution system inside the building, terminating at the service valve.

Water Supply System

The water service pipe, the water-distributing pipes and the necessary connecting pipes, fittings, control valves and appurtenances in or adjacent to the building or premises.

Water-Resistive Barrier

A material behind an exterior wall covering that is intended to resist liquid water that has penetrated behind the exterior covering from further intruding into the exterior wall assembly.

Weatherstripping

A material used to seal gaps around doors and windows, preventing air leaks and improving energy efficiency in a building. Proper weatherstripping can help reduce heating and cooling costs by keeping conditioned air inside and outside air from entering.

Wet Vent

A vent that receives the discharge of wastes from other fixtures.

Whole-House Mechanical Ventilation System

An exhaust system, supply system, or combination thereof that is designed to mechanically exchange indoor air for outdoor air where operating continuously or through a programmed intermittent schedule to satisfy the whole-house ventilation rate.

Windborne Debris Region

Areas within hurricane-prone regions located in accordance with one of the following: 1. Within 1 mile (1.61 km) of the mean high water line where an Exposure D condition exists upwind at the water line and the ultimate design wind speed, Vult, is 130 mph (58 m/s) or greater. 2. In areas where the ultimate design wind speed, Vult, is 140 mph (63 m/s) or greater; or Hawaii.

Winder

A tread with nonparallel edges.

Window Muntins

These are the narrow strips of wood or metal that divide the panes of glass in a window. They can enhance the aesthetic appeal of a window and are often found in traditional or decorative window designs.

Window Sash

A window sash is the part of a window that holds the glass panes in place and can be moved up and down or side to side. It typically consists of a frame that may include one or more panels of glass, and it is essential for the window's operation and insulation.

Wood Siding

Wood siding is a type of exterior cladding made from natural wood, used to protect and enhance the appearance of a building. It can come in various styles, such as shingles, boards, or panels, and requires regular maintenance to prevent rot, warping, and insect damage.

Wood Structural Panel

A panel manufactured from veneers; or wood strands or wafers; bonded together with waterproof synthetic resins or other suitable bonding systems. Examples of wood structural panels are plywood, orientated strand board (OSB) or composite panels.

X

Xeriscaping

A landscaping method that reduces or eliminates the need for irrigation by using drought-resistant plants and efficient design techniques. It focuses on conserving water while maintaining an attractive outdoor space.

Y

Yard

An open space, other than a court, unobstructed from the ground to the sky, on the lot on which a building is situated.

Z

Zoning

Zoning refers to the regulations that dictate how land can be used in specific areas, including the types of buildings allowed, their height, and their purpose (residential, commercial, industrial, etc.). These rules help ensure that land use is organized and compatible with surrounding properties.