Basement Building Code Checkers
Start with the escape window, the item most often missed in basement bedrooms.
Your result
Enter your numbers and press the button.
Egress rules at a glance
| Requirement | Minimum or maximum | IRC section |
|---|---|---|
| Net clear opening | 5.7 sq ft (5.0 sq ft at grade floor) | R310 |
| Clear opening height | 24 in minimum | R310 |
| Clear opening width | 20 in minimum | R310 |
| Sill height above floor | 44 in maximum | R310 |
| Window well area | 9 sq ft minimum | R310 |
| Well width and projection | 36 in minimum each | R310 |
| Well deeper than 44 in | Permanently attached ladder or steps | R310 |
Subsection numbers differ between IRC editions; the values are the same in the 2012–2021 city handouts cited below.
Ceiling heights (IRC R305)
| Space | Minimum |
|---|---|
| Habitable rooms and hallways | 7 ft |
| Bathrooms, toilet rooms, laundry rooms | 6 ft 8 in |
| Basement areas without habitable space | 6 ft 8 in |
| Under beams, girders, ducts in basements | 6 ft 4 in |
Where basement inspections usually fail
- Bedroom windows that are too small or too high, especially sliders and double-hungs measured by the frame instead of the opening.
- Window wells under 36 in deep from the wall, or deeper than 44 in with no ladder.
- Ceilings that dip under 6 ft 4 in at a duct or beam once drywall and flooring go in.
- Stairs with a short top or bottom riser after new flooring changes the floor levels.
- Missing fire blocking at the top of furred walls and around soffits.
Many cities publish one-page handouts on these items, like the St. Paul, Boise and Des Moines sheets cited on this site. Ask for your city's version before you frame.
Before you call for an inspection
- Measure every egress opening with the sash open and write the numbers on the frame.
- Measure ceiling height at the lowest duct or beam after the ceiling material is up.
- Check riser heights top and bottom after flooring.
- Leave insulation and vapor details visible until the insulation inspection if your town does one.
- Have the permit card and approved plans on site.
Codes this site uses
The checkers use the International Residential Code as printed in city and county handouts, and the 2021 International Energy Conservation Code for insulation. Most U.S. states adopt the IRC with local amendments, and adoption years differ. Where a state amendment is known to change a number, such as Minnesota's 6 ft 4 in allowance for existing basements, the page says so.
Sources
- https://www.stpaul.gov/sites/default/files/Media%20Root/Safety%20&%20Inspections/DSI.Bldg_EgressWindow.pdf
- https://www.cityofboise.org/media/3924/434-irc-code-section-r305-ceiling-height.pdf