Code Requirements for Residential Construction (2000 International Residential Code) Note: This section approximately follows the NFPA 5000 code for one- and two-family dwellings. Use the following checklist for residences.
The IRC applies to one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories in height with a separate means of egress,and their accessory structures.
Location on lot:
Openings must be 3 Feet from property line. Walls less than 3 Feet must be 1-hour construction. Windows not allowed in exterior walls with a fire separation distance of less than 3 Feet to the closest interior lot line (usually with parapet).
Separation between abutting dwelling units must be a minimum of 1 hour construction (1.2 hour, if protected by a sprinkler system).
Windows and ventilation:
Habitable rooms must have natural light and ventilation by exterior windows with area of at least 8% of floor area and 4% must be capable of being opened. Bath and laundry-type rooms must have ventilation by operable exterior windows with area of not less than 3 SF (1.2 to be capable of being opened.). In lieu of natural ventilation and light, mechanical ventilation and artificial lighting may be used.
Any room may be considered as a portion of an adjoining room when at least 1.2 of area of the common wall is open and provides an opening of at least 1.10 of floor area of interior room, but not less than 25 SF.
- At least one room shall have at least 120 SF.
- Other habitable rooms, except kitchens, shall have at least 70 SF.
- Kitchens shall be 50 SF, min.
- Habitable rooms shall be 7 Feet minimum.
- Ceiling heights 7 Feet min.
- Where exposed beams not less than 4 Feet apart, bottoms may be at 6 Feet-6 Inches.
- Basements, 6 Feet-8 Inches min. (6 Feet-4)