What is a Basement Egress Window?
A basement egress window is a larger-than-normal window designed to serve as a safe emergency exit from below-grade rooms. Unlike standard basement windows, egress windows must meet specific size requirements and have a clear path to the outside. They're installed in window wells that allow occupants to exit quickly during a fire or other emergency.
If you've spent time in a finished basement, you may have noticed these windows. They're not just a nice-to-have feature—in Colorado, they're often a legal requirement.
Colorado Building Code Requirements
Colorado's building code requires egress windows in any basement bedroom or sleeping area. The International Building Code (IBC), which Colorado adopts and enforces locally, sets strict standards for these windows.
Size and Dimensions
Egress windows must have a minimum opening of 5.7 square feet, with a minimum width of 20 inches and minimum height of 24 inches. For basements, the sill (the bottom of the window frame) cannot be more than 44 inches above the basement floor. These measurements ensure that a person of average size can climb through during an emergency, and that firefighters can enter if needed.
Window Well Requirements
If your egress window opens into a below-grade well, that well must be at least 9 square feet in area. You'll also need a permanent ladder or steps built into the well, and the well must have a removable cover or grate to keep debris and water out during normal conditions.
Why This Matters for Your Home
Building codes exist for good reasons. Basement egress windows directly impact life safety. If a fire or other emergency traps someone in a basement bedroom, an egress window provides an escape route that doesn't depend on the main stairwell. In a real emergency, those few extra seconds matter.
Beyond safety, proper egress windows also affect your home's resale value and your ability to legally use basement space. If you're planning to finish a basement and add a bedroom or second living area, you'll need to install egress windows to meet code—and to ensure your home can be insured and sold without issues down the road.
Cost Considerations
The cost of installing basement egress windows in Denver typically ranges from $1,500 to $3,500 per window, depending on several factors:
- Whether you're replacing an existing window or creating a new opening
- The size and type of window chosen
- Window well construction, including excavation and structural support
- Finishing details like gravel, grates, and ladders
- Your home's foundation type and soil conditions
While this isn't a small investment, think of it as part of the cost of finishing a basement legally and safely. Cutting corners here creates liability and can complicate future sales or insurance claims.
Installation and Professional Help
Installing egress windows requires cutting through your foundation, which is not a DIY project. It requires proper equipment, knowledge of your foundation's structure, and understanding of local building codes. You'll typically need a building permit and inspection to ensure the work meets Denver's requirements.
A professional contractor will handle the structural work, ensure proper drainage so water doesn't seep into your basement, and make sure the window well is correctly sized and installed. They'll also pull the necessary permits and coordinate with city inspectors.
Planning Your Basement Project
If you're thinking about finishing or improving your basement, start by understanding your egress window requirements early. This affects your overall project cost and timeline. A good contractor will help you choose the right window style, size, and location to meet code while fitting your home's design and budget.
At AD's Construction, we've installed countless egress windows in Denver basements, and we understand the local code requirements inside and out. If you're planning a basement project and want to know whether you need egress windows or how much they'll cost, we'd be happy to discuss it. Reach out to request a free estimate—we'll walk you through your options and answer your questions.