If music writers were more creative, the term "garage band" wouldn't be used in so cavalier a fashion.
Having attained critical mass in the late 1990s as a label for rock groups with a loud, sloppy sound allied to conventional song structures, the term is usually used for artists who, you can be sure, have never played in a garage.
Take Bjorn Ottenheim and Daan Schinkel, a drum-and-organ duo who go by the name of zZz. Although they've been pinned with the garage-band tag, according to their bio they first started playing in the basement of a farmhouse in the Netherlands. Reached at their home base in Amsterdam, they now rehearse in a very different environment.