Window replacement costs in Denver

Denver rewrote its window rules for historic homes this year. On February 17, 2026, the Landmark Preservation Commission adopted new guidelines for windows, doors and egress windows, and the chapter took effect March 3. The big change: most historic windows on a landmark or in a historic district may now be replaced, as long as they aren't character windows.

Character windows are the special ones: arched, round or bowed sash, leaded or stained glass, ornate muntin patterns, bay and oriel groupings, or windows too big to buy off the shelf now. Landmark staff or the commission decide which ones count. Those should be repaired, and replaced only when badly deteriorated. A plain one-over-one sash is a common window.

Common windows still have a recipe. Match the size and form of the historic windows on the house. On the front, no smaller unit boxed inside the old opening. Snap-in grids and grids only between the panes aren't allowed. A side the public can't see may take a simpler window. The city's landmark pages add that vinyl windows aren't allowed in historic districts or on individual landmarks.

Basement bedrooms get their own section. New egress windows belong on side or rear walls when possible, and a visible window well surround shouldn't rise more than six inches above grade.

Historic Denver, a private nonprofit, sums up the process: inside a district, a window replacement goes through design review.