Casement Windows for Basement Egress

casement windows — The Complete Guide

If you're finishing a basement bedroom in Aurora, casement windows come up fast, because they're the most common style used for egress window installation. This guide walks you through everything a homeowner needs to know before adding or upgrading an egress window: whether code actually requires one, what installation involves, what it costs, and how to keep the window well dry year-round. We install these windows every week in Aurora basements, so you'll get local, code-literate answers instead of generic national advice. By the end, you'll know exactly what to budget, what to ask a contractor, and how to plan the project around your remodel.

What You'll Find in This Guide

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Do You Need an Egress Window for a Basement Bedroom?

Short answer: if you want a legal basement bedroom, yes. Building code treats any sleeping room as a space someone might need to escape from during a fire. As a result, every basement bedroom needs an emergency escape and rescue opening, and in a basement that almost always means an egress window.

The requirements are specific. Under the IRC 2024 code, every basement sleeping room must have an emergency escape opening with at least 5.7 square feet of net clear opening area, according to EgressUSA. Beyond that, the opening must have a maximum sill height of 44 inches above the finished floor and a minimum net clear opening width of 20 inches, per The Great Egress Co. Those numbers matter more than they sound, because plenty of basement windows look big enough but fail the net clear opening test once you account for the frame and sash.

Here's the trap we see most often in Aurora: a homeowner finishes a basement bedroom without a permit, then tries to sell the house. The appraiser or inspector flags the room, and it can't be listed as a bedroom. That erases value from the remodel. It also creates a genuine safety problem, because a bedroom without a compliant exit is a bedroom your family can't escape from in an emergency.

A few red flags tend to show up together in these situations:

No permit on file with the city, even though the basement was clearly finished as living space
A window that looks large from inside but measures under 20 inches wide once you subtract the frame
A sill height well above 44 inches, often because the original window was never meant for egress
A window well that's missing, undersized, or lacks a code-compliant cover

What Counts as a Bedroom in the Eyes of an Inspector

You don't need a bed in the room for it to count. Inspectors look at whether a space could reasonably function as a sleeping room. For example, a finished room with a closet and a door will usually get treated as a bedroom, whether you call it an office or not. With this in mind, plan your egress window before you frame walls, not after.

Aurora follows the International Residential Code with local amendments, so verify current requirements with the City of Aurora Building Division before you finalize plans. Permit rules and inspection sequences occasionally change. We handle permit paperwork for our clients daily, and getting this step right up front saves weeks later. If you're unsure whether your existing window qualifies, measure the net clear opening, not the rough frame, and compare it against the numbers above.

Choosing the Best Egress Window Type: Why Casement Windows Win in Basements

Not every window style works for egress. The code cares about net clear opening, which is the actual unobstructed space a person can climb through. That single requirement eliminates most window types in a basement setting, where wall openings are limited by grade, foundation height, and framing.

A casement-style window dominates basement egress installations for a simple reason: it opens like a door. Because the entire sash swings outward on a hinge, nearly the full window area counts as clear opening. In practice, that means you can meet the 5.7 square foot requirement with a smaller rough opening and a smaller cut in your foundation wall. A smaller cut means less excavation, less structural work, and often a lower total cost.

Compare that to the alternatives:

Sliding windows open only halfway, so you need roughly double the window size to hit the same net clear opening
Single-hung and double-hung windows face the same problem in the vertical direction, since only part of the sash ever clears the frame
In-swing styles exist, but they eat into interior space and can conflict with furniture placement in a small bedroom
Sliders in walkout basements can still make sense where the wall opening is already generous

Given all this, most Aurora contractors default to a hinged, outward-swinging unit whenever the foundation cut needs to stay small.

What to Look for Beyond the Opening Size

Style is only part of the decision. Additionally, you should weigh energy performance, because Colorado basements see big temperature swings. Look for low-E glass and a solid frame material, typically vinyl for cost or fiberglass for durability. Operation matters too, since an egress window is a life-safety device and must open easily without keys, tools, or special knowledge. Test the crank or latch before you buy, and imagine a child or older adult operating it in the dark.

Finally, think about the view and light. An egress window is often the largest glass area in a finished basement. Paired with a properly sized window well, a well-chosen window style transforms a dark basement bedroom into a space with real daylight. That daylight is a big part of why finished basements hold value. In fact, a national basement remodel returns 71% of its cost at resale on average, the highest ROI among newly tracked project categories, according to the JLC Cost vs. Value Report.

Egress Window Cost, Installation Process, and Timeline

Budget is usually the first question we get, and the honest answer is that egress window cost depends on your foundation, soil, and site access. A straightforward installation in a poured concrete foundation with easy backyard access sits at the lower end. Conversely, projects with block foundations, tight side yards, buried utilities, or deep wells cost more. Get an itemized estimate that separates several distinct cost drivers:

Excavation and site restoration
Concrete cutting and any structural header work
The window unit itself, including glass and frame upgrades
The window well and its drainage system
Permit fees and inspection costs

If a contractor gives you one lump number with no breakdown, keep shopping.

What the Installation Process Actually Looks Like

The egress window installation process follows a predictable sequence. First, the contractor pulls permits and calls for utility locates. Next comes excavation outside the foundation, followed by cutting the opening in the concrete. Crews then install a header if the opening requires structural support, set and flash the window, and place the window well. Backfilling, drainage hookup, and interior finishing wrap up the job. An inspector typically checks the work at one or more stages before final sign-off.

As for the egress window installation timeline, most single-window projects take two to four days of on-site work once permits are in hand. However, permit review adds lead time, so plan several weeks from contract to completion. Weather matters too, since frozen ground in a Colorado winter slows excavation, though it rarely stops it entirely.

Window Well Drainage and Cover Options

Do not skip drainage. More than 60% of U.S. homes with basements experience some degree of water penetration or moisture problems, according to the American Society of Home Inspectors, and a poorly drained window well is a common culprit. Proper egress window well drainage means a gravel base, a drain connected to your perimeter drain or a dry well, and grading that moves surface water away from the well.

A cover completes the system. Window well cover options range from clear polycarbonate domes that shed rain and snow to flat grates that support foot traffic. Whichever you choose, code requires that the cover open from inside without tools, because a cover that traps someone in an emergency defeats the entire purpose. In Aurora, a sturdy cover also keeps hail, leaves, and the occasional curious pet out of the well.

Ready to Get Started?

You now know what code requires, why a hinged, outward-opening window is usually the right call, and what installation genuinely involves. The next step is finding out what your specific basement needs, and that starts with someone looking at your foundation, not a national calculator. Request a free estimate from our Aurora team, and we'll measure your space, walk you through permit requirements, and give you a real number you can plan around.