1. Provide disability accessibility features as required by the International Building Code for Group R-3 occupancy when at least () 4 dwelling or sleeping units are located in one building. This means that one and two-family homes and townhomes with fewer than (<) four units in one building need not have disability accessibility features.

Bathroom Light and Ventilation

Bathroom Light and Ventilation

1. Provide outdoor light and ventilation to bathrooms, toilet rooms, and similar areas using windows or doors containing glazing. Provide a total glazing area of at least () 3 square feet

with atleast () 1 ½ square feet operable. Open the glazing directly on to a street, public alley, or on to a yard or court located on the same lot. Read the full Topic

Deflection (Bending) of Structural Components

Limitations of the Material in this Section

Most readers should not deal with bending of structural components such as floors, walls, ceilings, and roofs. Leave this to qualified engineers and contractors. Because “spongy” floors and rattling walls are common complaints, this section explains some basic concepts involved in deflection and helps you understand when deflection may be excessive.

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Draftstopping helps limit the movement of air in floor framing and in floor/ceiling assemblies. Draftstopping may also be used as part of a fire separation measure in the

attic of a two-family dwelling. Draftstopping is most often required when using open web (metal plateconnected) floor trusses and when a ceiling is suspended under a floor. Do

not confuse draftstopping with fireblocking. Fireblocking occurs in wall assemblies. Read the full Topic

Emergency Escape Openings

Escape Opening Locations and General Requirements

1. Provide at least () one escape opening in every bedroom including bedrooms above, at, and below ground level. This escape opening is not required if the building is

equipped with an automatic fire sprinkler system. Read the full Topic

Exterior Doors

Egress Door Definition

Egress door: The egress door is a door to the outside that meets all egress door requirements. Every dwelling must have at least one egress door. The egress door is usually the

front door. Other exterior doors need not comply with the egress door requirements. Read the full Topic

Fire Seperation Between Buildings

Fire Separation Distance Definition

Fire separation distance: The fire separation distance is the horizontal distance between the

home’s exterior wall (the face of the building) and a fire separation line. The fire separation distance

is measured between the fire separation line and the exterior wall at a right angle to the

exterior wall. The fire separation line is usually the property line between lots. In urban settings

where buildings are close together and close to streets and sidewalks, the fire separation distance

may also be measured to the center line of a street, alley, or public sidewalk as determined by the

local building official. For two-family dwellings and townhouses, the fire separation line is an

imaginary line between dwellings. When two or more dwellings are attached, the fire separation

distance is zero. Read the full Topic

Fire Sprinkler System

1. Install an approved automatic fire sprinkler system in new one and two-family homes according to NFPA 13D or IRC Section P2904. Note that adoption of this provision may vary by jurisdiction. Verify local adoption with the local building official. Read the full Topic


Fireblocking:  Fireblocking (also called firestopping) limits the spread of fires vertically between

stories in concealed wood-framed walls and horizontally in long concealed areas such as double

walls, framed openings, and drop soffits above cabinets. Concealed vertical spaces in woodf ramed

walls can act like a chimney providing fire an easy and rapid path between stories. Lack

of fireblocking increases the chance of property damage and loss of life during a fire.

Do not confuse fireblocking with draftstopping. Draftstopping limits the horizontal movement of

air in concealed areas such as floor/ceiling assemblies. Read the full Topic

Flood Resistant Construction

1. Use flood-resistant construction in designated flood hazard areas. Verify with the local building official if the area is in a flood hazard area. Flood-resistant construction involves elevating the lowest floor level of the structure above the flood level, installing mechanical, electrical, and plumbing components above the flood level, and reinforcing the foundation to withstand forces from water and wave action. Refer to the IRC for more information about flood-resistant construction requirements.

Foam Plastic Insulation and Trim

Foam Plastic Products Definition

Foam plastic: Foam plastic products addressed in this section include: (a) extruded polystyrene sheet insulation from manufacturers such as Dow® and Owens Corning®, and (b) spray-applied polyisocyanurate foam products such as Great Stuff ® and spray-applied foam insulation that is now available for insulating wall cavities and for insulating around rafters in semi-conditioned attics, and (c) flexible interior trim moldings such as crown and base moldings. Read the full Topic


Guards Definition

Guard: A guard is a barrier that protects occupants from falling from a raised surface such as a stairway, deck, or balcony. Guards are often call guardrails when the guard also

serves as a handrail; however, guards need not be an open rail. A guard may be a partial height solid wall, a partial height wall containing safety glazing, or any other structure that

complies with IRC requirements. Read the full Topic

Habitable Rooms and Ventilation

Habitable Rooms Definition

Habitable rooms Habitable rooms (also called habitable spaces) are living, sleeping, eating, and cooking rooms. Bathrooms, toilet rooms, closets, hallways, storage and utility rooms are not habitable rooms. Habitable rooms have special size, ceiling height, heating, lighting, and ventilation, requirements. Rooms that are not considered habitable do not have those requirements. Habitable Rooms Light and Ventilation

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Hallway Dimensions

1. Build each hallway with a minimum finished width of at least () 36 inches. Read the full Topic



1. Provide a handrail on at least () one side of every continuous flight of stairs with four or more risers.

Height Read the full Topic

Insulation Clearance to Heat Producing Devices

Insulation Clearance Requirements

1. Provide at least () 3 inches clearance between combustible insulation and heat-producing devices such as recessed lighting fixtures and fan motors. Most insulation used in modern homes is considered combustible.

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Outdoor Air Intake Openings

Outdoor Air Intake Openings

1. Provide at least () 10 feet horizontal separation between all mechanical and gravity outdoor air intake openings and gas and oil vents, chimneys, plumbing vents, streets,

alleys, and similar contaminant sources. Gravity outdoor air intake openings include: (a) openings for makeup air and combustion air, and (b) attic eave vents, and (c) windows,

doors, and similar openings. Mechanical outdoor air intake openings include air intakes connected to furnaces and air handlers and powered air exchange ventilation systems. Read the full Topic

Penetrations in Fire-Resistive Walls and Ceilings

Summary of Penetration Requirements

1. Refer to the IRC Commentary for more information about fire-resistive wall and ceiling penetration requirements and exceptions. Most readers of this should not deal with this

complex subject. The following is a summary of the basic provisions. Read the full Topic

Plumbing Fixture Minimum Clearances and Requirements

Required Plumbing Fixtures

1. Provide every home with at least () one toilet, and one bathroom sink, and one tub or shower, and one kitchen sink.

Read the full Topic

Room Size and Ceiling Height Requirements

Habitable Rooms Dimensions

1. Provide every home with at least () one habitable room that has an area of at least () 120 square feet. Read the full Topic

Safety Glazing

Safety Glazing Labeling

1. Label every pane of glazing in a hazardous location with a permanent marking that identifies the type of glazing (usually tempered) and the safety glazing standard with which it

complies. This includes inside, outside, and any middle panes in a multiple-pane window or door. The glazing manufacturer usually etches this label into a corner of the glazing. See #2

below for the safety glazing standards that should appear on the label. Read the full Topic

Seismic and Wind Design Areas

Seismic Design Areas

1. Provide increased strength and structural integrity for foundations, walls, roofs, gas pipes and appliances, and other components in seismic design areas. Refer to the IRC and consult a qualified engineer or other qualified professional when building in seismic design areas.

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Site Address

1. Install approved building address numbers or letters that are clearly legible from the road fronting the property. This is so emergency responders can quickly locate the property. Make the letters or numbers Arabic type that are at least () 4 inches tall and at least () ½ inch wide. Make the letters and/or numbers contrast with the background.

Skylights and Sloped Glazing

Sloped Glazing Definition

Sloped glazing, including skylights, is any glazing material installed with a slope of at least () 15 degrees from vertical. The glazing may be on a roof or in a wall. If the glazing slopes at least () 15 degrees from vertical, it is sloped glazing.

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Smoke and Carbon Monoxide Alarms

Smoke Alarm Required Locations

1. Locate a smoke alarm: (a) in every bedroom, and (b) outside all bedroom areas in the immediate vicinity (usually about 10 feet) of all bedrooms, and (c) on every level in the home,

including basements and habitable attics. Read the full Topic

Stairway Lighting

Interior Stairway Light Locations

1. Locate a light fixture near each stairway landing, including the top, bottom, and any intermediate landings. You may locate a light fixture directly over each stairway section instead of near each landing. The light must be capable of illuminating treads and landings of interior stairs to at least () 1 foot-candle.

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Stairway Definitions

Landing: A landing is a flat surface at the top and bottom of a stairway. Landings may also occur at points within a stairway. A landing must be at least () as wide as the stairway and at least () 36 inches deep.

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Termite Protection

1. Provide protection against termite damage in areas subject to termites. These areas include almost all of the continental United States except areas in the far north. You may use any

approved protection method including: Read the full Topic


Townhouse Construction

1. Build townhouses as structurally independent buildings. The foundation and a 2 hour fire resistive common wall need not be structurally independent. Read the full Topic

Two Family Dwellings

Fire Separation of Two Dwelling Units in One Building

1. Separate two-family dwelling units that are built side-by-side in one building by building at least () a 1 hour fi re-resistive common wall between the dwellings. Build the common wall continuous between the foundation and the underside of the roof sheathing. Make the common wall tight against the foundation and the roof sheathing.

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Wood on Concrete and Masonary, Wood in he Ground, Wood Exposed to the Weather

Treated and Decay Resistant Wood Definitions

Treated wood: Treated wood (also called pressure treated) is wood into which chemicals have been forced under pressure. The chemicals help the wood resist insects and decay. Note that the cut ends, holes, and notches in treated wood are not insect and decay resistant. Cuts, holes, and notches must be field treated to restore resistance. Note that smaller dimensions of treated wood (such as 2×4) may not be suitable for direct ground contact. Verify ground contact rating of treated wood with the wood supplier.

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