What Bedroom Egress Actually Requires (And Why Window Size Isn't Enough)

Every bedroom needs an emergency exit that isn't the door — usually a window. The building code calls this egress, and it's one of the most misunderstood requirements in residential construction. Most people assume any reasonably sized window qualifies. It doesn't.

What Egress Means

Under the International Residential Code (IRC R310.2.1), every bedroom needs at least one window or door that opens directly to the outside and is large enough for a person to climb through in an emergency, and for a firefighter to climb in wearing full gear. That's the whole point of the rule.

The Numbers That Matter

●      Minimum net clear opening area: 5.7 square feet

●      Minimum clear opening height: 24 inches

●      Minimum clear opening width: 20 inches

●      Maximum sill height above the floor: 44 inches

The key phrase is “net clear opening.” That's not the size of the window unit — it's how much of it actually opens.

Egress Window Requirements

Why Double Hung Windows Are Tricky

A double hung window only opens on one sash, so the real opening is roughly half the total window height. A window that looks generously sized on a floor plan can fall well short of the 5.7 square foot requirement once you account for how it actually operates. Casement windows, which swing open on a hinge, don't have this problem — nearly the whole unit counts as clear opening.

What This Means for Your Project

If you're planning a bedroom addition or remodel, window selection isn't just a style decision — it affects whether your design passes inspection the first time. We check egress on every bedroom window during design, before it ever reaches a contractor or a building inspector.

Have a project in mind? Grab our free Homeowner Budget Worksheet or Questions to Ask Before You Hire an Architect guide to get started — links on our Free Resources page.