48 long is great, can get 2 cars into end to end if needed with a bench along the front but 28 is too narrow if cars come in gable end, 36 wide for 2 cars side by side. One of my buds has 30 and all the space along the walls is about useless, just not enough room. Floor space is a funny thing, the first thought that comes to mind is that but its really wall space thats as important as anything.
Same for my own building, only reason to build bigger was for more along the walls,extra 20 ft would have netted 40 but drove the cost up some, added to heat demands and walking distance. """"They don't know what you want or need. You do."""" I would say the want part of that might be accurate but I see more than one garage looks like its designed by a bunch of monkeys armed with a metric pencil and a six pack. Really kills me to see door placement wrong, doors in eve sides where it would have been just as simple or easier to put them in the end. Many of these goof ups are aided by builders who agree with everything the customer says, do not give them benefit of experience, builders are not always a great value added help.
I see one a while back where that was the case, after the fact the guy says,,, wish I done this or that, some of it didn't cost much or near free but the builder in such a hurry to sign the guy up he doesn't want to make waves. Elevation all fucked up, too close to the road, how hard is it to know,,, it snows here?