I spent a year designing my garage back in 2012. I looked at every article I could get and talked to the experts. Mine was only for my two cars as the City of Vancouver wouldn't let me build over 490 Sq Ft. Its approx 23x21. I'd need a lot more space than that to park my Grady. Anyway, I learned a lot and built it the way I wanted as its my man cave and really an extension of my house. Frankly its as important as the living room if you ask me. Anyway, a couple of things I did; Make sure you have some grade in the floor to allow water run off. Make sure you ask the contractor to use a high quality concrete floor finish so its smooth as a babies rear. This allows me to keep the floor spotless. I foam insulated it to make it heat efficient. In order to allow humidity to be expelled, I installed a Dragon exhaust system set up on a humidistat. They are made in the Eastern US and are bullet proof. You can smoke a Cohiba in there and just suck the smoke right out. I put in 60 amp service as I wanted plenty of power. I installed 25 outlets, 8 alone at the workbench which is just enough. You can't have too many outlets. I put in a 220 Volt Oullet heating system mounted on the roof. It keeps the garage at 15-17 degrees or warmer during the cool months and cost very little in power. I put a fan in it to keep air circulating. I also installed hot water by way of an on demand system I bought at Home Depot called Stiebel Elton (German) that gives me all the hot water I want only as needed. Its great and again is cheap to operate as it only works when you turn it on. Oh, and I wired it for internet, house alarm/video security, comms to house and my Sonos system. You gotta have technology and tunes. Of course a fridge full of cold Peroni's and frozen Anchovies. Next project is to get a TV out there.