And before they started turning into luxury "loft" apartments disused factories/warehouses were perfect environments to set up micro "practice spaces."
No 'garage' is also a music genre. I'm not into music really (certainly not that kind) but I think it's in some way related to but to mark distinction from 'house'.
Of course funnily enough 'the house band' could also be a thing, but neither is related to the genre of that name.
Edit: oh, seems it's a UK thing, so perhaps you weren't to know - https://en.m.wikipedia.org/wiki/UK_garage. Though also older 'garage rock' (60s) on the disambiguation page.
In the US “house” usually refers to the venue - house wine, house band, etc means that supplied by the hotel. You rent a ballroom, you want a band, the hotel can provide the house version, kind of generic.