This post originally appeared on the Green Building Advisor website.
According to code, a garage is considered an accessory building when detached from a dwelling, and outside the conditioned envelope when attached to the dwelling structure. They don’t fall under the same energy code requirements as a dwelling. That being said, it’s common in my market for both attached and detached garages to have some sort of heat source (I live in a very cold climate). If you are going through the trouble and expense of conditioning a garage, it’s probably wise to also think about its efficiency, both insulation and air sealing.