Here is mine.... heated by natural gas...usually to about 55-60º F. Has drains in floor, 50 Amp shore power which I think is shown, and a clean out along with fresh water source on the curb side, back water flush supply on the road side. Garage is total of 58 feet long about 15 feet wide.
, on Flickr
Two of the walls are about nine feet underground, so in summer, even when 90º + outside the garage, has never exceeded 83º F inside unless the doors are left open for several hours. On the other side of the garage (curb side) are three car bays about 23' deep.
Lighting is by sodium vapor lamps which provide the equivalent of about 1000 watts incandescent lighting. Also, motion activated LED floods light things up whenever one enters the garage.
Overall i am quite pleased as this allows me to keep the trailer open as noted in the photo and I can work in it at any time by simply cranking up the gas heat to about 70º.