Egress Windows and Home Inspections in Denver
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Buying or selling a home with a basement bedroom? Check its window against the code numbers: at least 5.7 sq ft net clear, 24 in. high, 20 in. wide, and a sill no higher than 44 in. (IRC R319 in Denver's 2025 code). If it falls short, we cut the opening, install the window and set the well. (2025 Denver Building Code)
Informational only. This is not legal or real estate advice. Your building department makes the final call.
What to measure before listing or closing
- Net clear opening: at least 5.7 sq ft. This applies to every egress opening, including those at or below grade.
- Net clear height at least 24 in.; net clear width at least 20 in.
- Sill no higher than 44 in. above the floor.
- Window well: at least 9 sq ft, with horizontal projection and width each at least 36 in., and the window must open fully inside it.
- Well deeper than 44 in.: a ladder is required, and it may not encroach more than 6 in. into the well.
Section: R319 in Denver (2025 Denver Building Code) and the other 2024-IRC jurisdictions (Arvada, Thornton, Littleton, Englewood, unincorporated Jefferson and Adams counties); R310 where the 2021 IRC still applies (Aurora, Lakewood, Centennial, Douglas and unincorporated Arapahoe counties). Figures are the base IRC numbers in our verified code file (ICC). Local amendments outside Denver, Douglas County and Centennial have not been verified, so confirm with your building department.
Existing windows in Denver
Denver's 2025 Residential Code adds item 3 to R319.5: an existing operable window must provide at least 4 sq ft net clear, 22 in. high and 20 in. wide. Where a change of occupancy requires egress, Appendix BO108.8.3 accepts an existing window at that size, or a replacement at that size that is the manufacturer's largest standard size fitting the existing opening (2025 DBC). Confirm with Denver CPD how this applies to your house.
Was the basement finish permitted?
Adding or enlarging a window opening in Denver requires a permit (CPD). Ask the seller for the permit record for the basement finish and the egress work.
Related
Services: Egress window installation · Window well installation · Basement egress cutting Guides: Egress window cost guide · Permit guide · Egress code guide · Egress window check Cities: Denver · Aurora · Lakewood · Arvada · Centennial
Frequently asked questions
What egress size should a basement bedroom have?
For new openings: at least 5.7 sq ft net clear, 24 in. high, 20 in. wide, with a sill no higher than 44 in. (IRC R319 / R310).
Does Denver accept a smaller existing basement window?
Denver's 2025 code (R319.5 item 3) sets an existing operable window at 4 sq ft net clear, 22 in. high and 20 in. wide. Confirm with Denver CPD for your house.
Does a window well count in the inspection?
Under the code, the well must be at least 9 sq ft with 36 in. projection and width, the window must open fully inside it, and wells deeper than 44 in. need a ladder.
Can an egress window be added before closing?
It needs a permit in Denver (CPD). Timing depends on the permit office and the job, so plan early.