Common Code Provisions Applicable to Residential Construction

This page is a summary of common residential code requirements organized by topic. This document was prepared as an in-house checklist, but may be a useful summary for builders as well. Based on 2009 International Residential Code. Please contact the Building Department for more specific information.


  1. Hazardous glazing locations - tempered glass required if windows within 24" of either edge of a door, windows within 60" vertically above a bathtub drain, or individual panes greater than 9 square feet in area and within 18" of the floor must be tempered glass, or glass within five feet horizontally of a stairway or landing and which is less than 60 inches above a walking surface.
  2. All wood in contact with concrete must be pressure treated.
  3. If girders are less than 12" from earth, or if joists are less than 18" from earth, the entire subfloor and supporting structure must be of wood which is pressure treated or naturally resistant to decay.
  4. In dwelling units, a smoke detector shall be installed in each sleeping room and at a point centrally located in the corridor or area giving access to each separate sleeping area. When the dwelling unit has more than one story and in dwellings with basements, a detector shall be installed on each story and in the basement.
  5. Heating room occupancy separation: one-hour fire-resistive construction is required to separate this room from the rest of the structure. Combustion air must be supplied through ducts or openings sized depending on the Btu rating of the furnace and the "tightness" of the structure.
  6. Chimney termination must be 2 feet higher than the ridge or roof within 10 feet of the top of the stack.
  7. "Metalsbestos" chimney must be 2" clear of all combustible materials, including gypsum wall board.
  8. A minimum 6 mil vapor barrier is required on the inner face of all exterior walls and the top floor ceiling. Also under house against ground or under slab.
  9. To meet passive ventilation requirements: In habitable space, openings in the exterior walls must be provided that are equal to or greater than 1/20 of the floor area served. To meet natural light requirements, there must be windows equal to 1/10 of the floor area served. (Kitchens may be provided with artificial light.)
  10. Hot water tank must be secured to prevent movement in an earthquake.
  11. When a building permit is issued for the alteration of a residence and the project value exceeds $1000.00 smoke detectors must be installed throughout the dwelling in accordance with present day code.
  12. All wood left exposed to the weather must be pressure treated or be naturally resistant to rot and decay. This provision applies to the exposed ends of structural members as well as siding, fascia, etc. These may be protected with flashing.
  13. Most homes require a carbon monoxide detector (by State regulation).
  14. Arc-fault circuit interrupter protection is required for most branch circuits.


  1. Exterior entry light required.
  2. Gutters and downspouts required.
  3. Minimum of two exterior GFI- protected outlets required.
  4. Minimum one frost-free hose bibb with integral backflow prevention required.


  1. Code requires a minimum of one square foot net clear ventilation per every 150 square feet of under floor area or attic area.
  2. Attic / roof space must be ventilated. Maintain 1" (2" recommended) minimum air space between roof deck and insulation.
  3. Switched light required within ready reach of space access panel or door.
  4. Attic scuttle minimum size: 22" X 30", with minimum 30" headroom at access. (No scuttle required if less than 30" maximum vertical height in attic.) Must be located in "hallway or corridor or other readily accessible location."
  5. Crawl space access minimum size: 18" X 24", unobstructed by pipes, ducts, etc.


  1. Egress window required for each bedroom: min. net clear opening-5.7 square feet. (Grade floor windows only - 5.0 square feet.) Min. width---------------20" Min. height--------------24" Max. sill height---------44"
  2. Required egress windows with a finished sill height below the adjacent ground elevation shall have a window well as follows: The well will allow the window to be fully opened with a minimum accessible net clear opening of 9 square feet, with a minimum dimension of 36". Wells with a depth of more than 44" shall be equipped with a ladder built to certain specifications. See Building Dept. for details.
  3. Smoke detectors required - hard wired with battery backup.


  1. One-hour fire-resistive construction required between dwelling and garage; door must be min. 20 minute rated or 1 3/8' thick solid core wood , self-closing device required in either case.
  2. All garage outlets must be GFI-protected.
  3. All source of glow, spark, or flame must be 18" min. above garage slab.
  4. Garage floors must be non-combustible and non-absorbent (i.e., concrete).
  5. Smoke detector required if garage is heated or tempered.


  1. Toilet rooms must be mechanically ventilated with a system capable of 5 air changes per hour, and with duct termination a minimum of 3' from any building opening, or be provided with opening windows with an area equal to or greater than 1/20 of the floor area of the room, with a minimum of 1½ square feet.
  2. Bathroom outlets serving counter top surfaces must be GFI protected.
  3. Hot is on the left.


  1. Minimum of one GFI-protected outlet located within 12" of island or peninsula surface required.
  2. All outlets serving a kitchen counter top surfaces must be GFI protected.


  1. Handrail must terminate in a post or a return to wall, both ends.
  2. Handrail required when four or more risers, regardless if "30"-above-grade" standard for guardrails is exceeded.
  3. Maximum riser height 7 3/4", minimum tread width 10". Tread lengths must be within 3/8" of each other, and riser heights must be within 3/8" of each other.
  4. Landing at top of ramp must extend 5' minimum in direction of travel.
  5. Stair handrail height must be between 34-38" above tread nosing.
  6. Guardrails required when a walking surface is 30" or more above adjacent grade. Min residential guardrail height is 36". (Commercial min is 42".)
  7. For both guardrails and handrails all spaces below top rail must of a size that a sphere no larger than 4" can pass through.
  8. Headroom above stairs must be minimum 6'8", measured vertically from the sloped plane adjoining the tread nosings.


  1. The National Electric Code requires that occupants of a given space have constant ready access to the overcurrent protection devices for the circuits in that space. Therefore a separate electrical panel is required for each living unit.
  2. Attic access openings, 22"x30" minimum, must be provided for each dwelling unit.
  3. One hour separation between dwelling units is required. A draft stop must be installed in the attic space above and in line with the walls separating the individual dwelling units. If the draft stop is constructed as for one-hour construction, the access hatches may be unrated. If the draft stop is not of one hour construction, the access hatches must be of one-hour fire resistive construction. Contact Building Department for details.