I put a 60 AMP subpannel in it. rented a trencher for half a day and laid the conduit in (18 inches deep). Had my son in law help pull the wires through. Got step by step instructions from an electrician friend in the ward. Saved about a $1,000 on electric alone. If you've never done electric, I'd recommend hiring that out.

I built it on block piers with a 3/4" T&G plywood floor. Easy and much cheaper than concrete slab.

Building it was fun and took a week. last summer I insulated it and added a window A/C unit (Arizona - I had to). Mine doubles as storage for my tools and a workshop.

ALSO....Whatever you think you need, make it a little bigger. Trust me, you'll fill it up faster than you think and wish you'd built a littler larger.