What Is Going On
With 160,961 owner-occupied houses across the service area, and most of that stock built before 1960, a lot of these garages were framed and finished before anyone thought about R-value on a garage door. On an attached garage, a warped panel or a worn bottom seal doesn't just let cold air into the garage - it lets cold air push against the wall of whatever room is on the other side, which in a lot of these older rowhomes is a kitchen, a laundry room, or a bedroom above it. On a detached garage, the same worn seal just makes the garage colder. Nobody upstairs feels it. That's the whole difference. We see attached-garage calls where the actual complaint is 'the kitchen floor is cold' and the real cause is three feet away at the garage door. Detached-garage calls are almost always about the door and the door only - ice at the bottom, a track that's racked from frost heave, a spring that's lost tension in the cold. Same climate, same age of house, different failure that shows up first.
What Most People Get Wrong
The mistake we run into most is treating every door in this climate band the same way, buying whatever's cheapest without asking whether the garage is attached or detached. On an attached garage, an uninsulated door is a hole in your building envelope, full stop, and in a cold severe climate that shows up on a heating bill even if nobody in the house connects the two. On a detached garage, insulation matters less for comfort and more for keeping condensation off tools and a car's undercarriage from freezing to the slab. People also assume a detached garage door doesn't need the same seal quality because 'nobody lives out there' - but a detached garage with a bad seal fills with drifted snow and ice at the threshold faster than an attached one, because there's no house heat bleeding in at all to keep it above freezing. We can't tell you which mistake your specific door is making without seeing it. That's not a sales line, it's just true - a door that looks fine from the driveway can be doing either of these wrong.
