Why This Page Exists
The building code's egress section reads like it was written for lawyers, not homeowners. But the rules themselves are simple — a short list of minimums that any basement bedroom window must meet. This page translates them. Note: Maryland's code is based on the International Residential Code (IRC), and Baltimore City and Baltimore County each run their own permit office. Use this page to understand the rules, then confirm the exact requirements with your local permit office before you build.
The Window: Four Numbers
1. Clear opening area: 5.7 square feet. Not the window size — the clear space you climb through when it is open. (If the sill sits at grade level, the minimum drops to 5.0 square feet.) Measure the open hole, not the frame.
2. Clear width: at least 20 inches. The narrowest dimension of the open window must clear 20 inches.
3. Clear height: at least 24 inches. The shortest dimension of the open window must clear 24 inches.
4. Sill height: no more than 44 inches above the floor. Measure from the basement floor to the bottom of the clear opening. Higher than 44 inches and a kid cannot reach it — so the code says no.
All four must be true at the same time. A window that is big enough but too high fails. A window low enough but too small fails. This is why casements are popular — the whole frame opens, so hitting all four numbers is easier.
The Well: Three More Numbers
5. Well area: at least 9 square feet. The horizontal footprint of the window well — room to stand and climb.
6. Well projection: at least 36 inches from the wall. The well must extend three feet out, so the window can open fully into it and a person can maneuver.
7. Ladder past 44 inches deep. If the well is deeper than 44 inches — most are — it needs a permanently attached ladder. Not a loose ladder. Attached.
The Operation Rule
8. Opens from inside, no tools, no keys, no special knowledge. This one kills more "egress windows" than any size rule. A window nailed shut, painted shut, blocked by security bars that need a key, or fitted with a crank only an adult can reach — none of those count. The test is simple: could a scared ten-year-old get it open in the dark? If not, it is not an egress window.
Which Rooms Need One
Every sleeping room below grade needs one — and every sleeping room needs a compliant escape opening generally, basement or not. A basement office, gym, or laundry room does not trigger the rule. But the moment a room becomes a place where someone sleeps — a bedroom, a guest room, an in-law suite — the requirement attaches. Finishing a basement without planning the window is the most common way Baltimore homeowners end up out of compliance.
New Work vs. Old Houses
New construction and permitted renovations must meet the current code, full stop. Existing homes are generally not forced to retrofit until something changes — a renovation, a permit, a sale. But inspectors apply current rules to any room you touch, and buyers' inspectors flag non-compliant bedrooms regardless of the home's age. The code is the floor, not the ceiling: even where you are not forced, the window is worth doing for the safety alone.
Ready to make your basement comply? See how installation works, or call (301) 679-9193 for a free written estimate.