What Local Conditions Do
Pomona's housing stock runs from 1951 to 2007, with the median landing around 1965 - squarely in the stretch when attached two-car garages became the standard way to build here. That matters because an attached garage shares a wall, and sometimes a ceiling joist, with the living space next to it. Pomona sits in a moderate-heat climate band, which means that shared wall sees real afternoon heat load most of the year. A door without a thermal break on an attached garage lets that heat work into the house side of the wall; a detached garage just radiates it back outside. If your garage was built in that 1960s-70s wave that makes up most of Pomona's stock, the door was likely sized and hung for whichever setup your house has, and swapping the door type without checking the framing underneath it can leave gaps at the header or jamb. The fix isn't exotic - it's matching the door to the structure it's actually bolted to, not to a generic spec sheet.
Checking It Yourself
Walk out and look at where the garage meets the house. If there's a shared interior wall or a door straight into the kitchen or laundry, you've got an attached setup, and from Pomona's 1965-median build era that interior wall often has thinner insulation than the exterior walls around it - worth a hand pressed against it on a hot afternoon. If the garage stands alone with its own roofline, it's detached, and the main thing to check is the header clearance and whether the track hardware has rusted from sitting in full sun with no adjacent structure for shade. On either type, look at the weatherstripping along the bottom and sides. Houses from the 1960s and 70s stretch that makes up most of Pomona's stock were built before foam-core insulated doors were common, so a lot of these garages are still running older slab doors that were never meant to block heat in the first place, attached or not.
The Common Mistake
The mistake we see most is someone replacing an attached garage door with whatever's cheapest, without factoring in that the garage backs onto a bedroom or living room wall. In Pomona's moderate-heat climate, an uninsulated or poorly sealed door on an attached garage pushes heat into that shared wall all summer, and the homeowner never connects the warm bedroom to the garage door until someone points it out. On a detached structure, that same cheap door is a non-issue because there's no shared wall to heat. The honest limitation here: we can tell you which type of door suits which setup, but we can't tell you from a FACTS sheet what your specific wall insulation looks like - that's a hands-on call, not a guess from housing-era averages.
