Which Window Styles Meet Egress Requirements?

Not all window styles are equal when it comes to egress. According to the International Residential Code (IRC), the *clear opening* is what matters—and different window styles deliver different clear openings for the same rough opening size.

Egress Requirements Recap

According to IRC R310:

• Minimum 5.7 sq ft clear opening
• Minimum 24" clear opening height
• Minimum 20" clear opening width
• Maximum 44" sill height

Window Styles Compared

According to FGIA and ICC guidance:

Casement Windows

How they open: Entire sash swings outward on hinges

Egress efficiency: Excellent—nearly 100% of glass area becomes clear opening

Why they excel: The same size casement window provides more egress area than any other style

Consideration: Some codes require minimum 90° opening for egress credit

Typical egress size: 24" × 36" often sufficient

Double-Hung Windows

How they open: Bottom sash slides up

Egress efficiency: Moderate—only bottom sash opening counts

Why they're common: Traditional appearance, versatile

Consideration: Need larger overall window for same egress area

Typical egress size: 24" × 48" or larger

Sliding (Gliding) Windows

How they open: One panel slides horizontally behind the other

Egress efficiency: Moderate—only sliding panel opening counts

Why they work: Horizontal format can fit where vertical windows can't

Typical egress size: 24" × 48" or larger

Awning Windows

How they open: Bottom swings outward

Egress efficiency: Poor—limited opening even when fully open

Typical use: Rarely suitable for egress; check specs carefully

Hopper Windows

How they open: Top swings inward

Egress efficiency: Poor—similar limitations to awning

Typical use: Basement ventilation, not egress

Size Comparison for 5.7 sq ft Egress

According to FGIA typical products:

| Style | Approximate Frame Size Needed |
|-------|-------------------------------|
| Casement | 26" × 40" (smallest option) |
| Double-hung | 30" × 56" |
| Sliding | 48" × 36" |

Casement windows require smallest overall size for same egress opening.

The Bottom Line

For bedrooms where egress matters, casement windows provide the most efficient path to compliance. According to ICC, whatever style you choose, verify the *clear opening* dimensions on product specifications—not just the frame size.

*For complete egress guidance, see: [Egress Window Requirements](/guides/egress-window-requirements)*