Good advice. I know a few people who built large shops that ended up costing them more than anticipated and then they were short money to do anything with their cars for awhile until the money situation caught back up.

Also if you think you may want to add more building later place the building on the property such that adding another 10-15 more feet or whatever more to the back of it in the future still works. It's easy to remove one blank shop wall and pour a new slab extension up against the existing and build new walls on down to follow.

If you live in a neighborhood there are likely rules that dictate how high above the fence it can be and where you can put it. In some upper scale neighborhoods they won't let you build a shop at all No boats or trailers in the backyard or anything showing above the fence from the street.