We are in the country and have a very large yard. I put a 20 foot high 41 feet long and 40 foot wide metal shed up. I left mine open at both ends so I could just drive thru. I keep my 20 foot bass boat, jeep wrangler, 40 foot fifth wheel and my dually under it with no problem. I ran power to it with two 30 amp outlets with one 50 amp outlet. I had a 40 foot dp for a few years which also fit fine. If I was putting up one I would definitely make it high enough to check the roof out while under the shed. You never know when you will need to get up there.
I didn't need a work shop as we have an attached two car garage so it all depends on your room and what you want. Just don't go too small.