Window replacement costs in Washington

Inside the District's historic districts, window rules are written into DC's municipal regulations. The Historic Preservation Review Board's window standards say replacing windows in a historic district takes a permit, and that goes for swapping just the sashes in old frames, too.

If your Washington rowhouse is four stories or less and has under 100 feet of frontage on any one street, it counts as a small building. On its front, a replacement has to reasonably match the historic window in layout, how it opens, profile, size, material and finish. Wood is replaced with wood, and the standards say a window clad in metal or vinyl doesn't match the finish of a wood one. Double glazing is fine, but grids sealed between the panes or snapped on don't count as muntins.

Around back there's more room. If a window can't be seen from a street or public open space, the new one mainly has to match how it opens and its size, as long as it isn't a special window like stained or curved glass.

Plenty of window work needs no permit at all, even in a historic district: new glass and glazing putty, scraping and repainting sash, caulking, weatherstripping, and new hardware, down to the pulley chains.