Egress

Fire is why egress exists as a code word. The International Residential Code splits it in two. Section R311 covers the everyday way out: one side-hinged exterior door, hallways at least 36 inches wide, stairs you can take fast in the dark. Section R310 covers the backup route, and that is the half that actually shapes a custom home.

Every sleeping room, every basement, and every habitable attic needs at least one operable emergency escape and rescue opening. Almost always that means a window. The 2021 IRC pins it to four numbers, all measured with the window opened the normal way from inside: a net clear opening of at least 5.7 square feet, at least 24 inches of clear height, at least 20 inches of clear width, and a sill no higher than 44 inches above the finished floor. An opening on the grade floor may drop to 5 square feet. Net clear means the hole a body fits through, not the rough opening the framer cut.

Those numbers fight each other on purpose. Twenty-four inches by twenty inches is only 3.3 square feet, so one dimension has to grow well past its minimum.

For example, a single-hung window opens only half its height, so a Fountain Hills bedroom needs a tall enough unit that the open half still clears 24 inches. Casements pass more easily, because the whole sash swings out. The 44 inch sill then collides with things Valley buyers ask for: deep window seats, floor-to-ceiling glass walls, platform beds. Tag the egress units on your window schedule so the framer sets the right rough opening the first time. Inspectors check egress at framing and again at the final inspection, and a bedroom window moved after stucco is a real bill.