Egress windows in Denver

Updated October 2026 · 6 public sources cited

If your basement finish includes a bedroom, the egress window is often the hardest part. In Denver it always needs a permit, and in historic districts it also needs design approval.¹²

Permits

Denver requires permits for new egress windows and for adding or resizing any window opening.¹ Denver's 2022 building code, which adopts the International Residential Code with Denver amendments, sets the egress rules your plan reviewer will check.⁴

The standard size rules

Under the International Residential Code, an egress opening needs:³

• at least 5.7 square feet of net clear opening,
• at least 20 inches of clear width and 24 inches of clear height,
• a sill no more than 44 inches above the finished floor, and
• if the sill is below ground, a window well of at least 9 square feet, with a permanent ladder when the well is deeper than 44 inches.

These are the same figures the Pikes Peak Regional Building Department lists for Colorado Springs.⁵ Confirm with Denver plan review, since Denver amends the IRC.⁴

Historic districts and landmarks

Denver's Landmark Preservation staff review egress windows on every individual landmark and every property in a historic district. Applications go through e-permits as a "Landmark Certificate of Appropriateness" and must include labeled photos, site plans, elevations, detailed sections at the window and window well, and a window schedule.² Plan extra time, and expect design questions about where the window and well can go.

What drives the price

• Foundation type. Cutting poured concrete takes longer and costs more than cutting block.³
• Digging. Below-grade windows need excavation for the well; tight lots may mean hand digging.³
• Drainage. A drainage system for the well runs $1,000 to $4,000 nationally.³
• Permits. HomeGuide puts egress permits at $200 to $500 or more nationally; Denver's fee depends on valuation (see the Denver cost page).³⁶

Back to basement finishing in Denver.

General information summarized from the public sources listed below. It isn't professional, engineering or legal advice. Codes and programs change; confirm current requirements with your local building department or utility before you start.