Window replacement costs in Los Angeles

In the city of Los Angeles, swapping a window for one of the same size and type gets an express permit. LADBS issues those at its permit counters with no plan check. The same bulletin adds a rule for houses three stories or less: every replacement window has to be dual glazed and carry a National Fenestration Rating Council label, the sticker that lists its tested ratings. That bulletin is the city's. If you live in one of the county's other cities, its own building department sets the process.

The energy numbers depend on which part of the basin you're in. The state Energy Commission's ZIP code list puts downtown and Hollywood in climate Zone 9 and much of Long Beach in Zone 6. In both, swapping out more than 75 square feet of windows means the new units must be rated U-0.30 or lower, and their solar heat gain coefficient can't top 0.23. Up in Lancaster and Palmdale, Zone 14, the U-factor cap tightens to 0.27.

There's a lot of old glass for those rules to meet. Half the homes in the Los Angeles metro were built in 1969 or earlier, and more of today's houses date from the 1950s than from any other decade.