When I did day care in Air Force base housing, many of the providers used the garage area for day care. I know several do it in my area now.
When we bought our current home, we converted the garage (which goes under the house) into a family room, decked out to look like a cabin!
I got these pics off the web, but it gives you an idea of how a garage can be used (and be turned back into garage later if wanted)