Recommendations for RV Garage?

I'm just finishing up building my "dream" garage. Started last summer and just today started finishing the ceiling. Here's my story and I hope some of it is uselful for you. Mine is a biggie; 30'Wx45'Lx14'H. I built it to hold my 30' C on one side and my restored Tbird and Corvette on the other. I park my golf kart in front of the rv. In between the rv and the cars I had room to build a 16' long train table for my grandson and still am able to open both slideouts. I also built a workbench across the back wall. The door is 12'H and insulated with an electric motor. I put spray insulation on the walls and will also spray the ceiling when finished. I installed one walk-in door and no windows. I have no AC but will install two large ceiling fans and install radiant heaters before winter. Thirty year guaranteed roof shingles. I installed 6 very powerful fluorescent fixtures that hold 6 lamps each. I had to do some landscaping to level the ground and luckily had an old stone wall and several large rocks to help do the fill. Obviously my floor is very thick but if your site is level and you pour a 5" floor, you can park an Abrams tank on it. Installed drain in center of floor of course. Used 6" instead of 4" lumber for the frame for added strength and braced at intervals between 24" offset. It gets a lot colder where you are than where I live so I won't advise on how to heat your garage. Install a big enough electrical box so you'll have more than enough space for breakers. I placed outlets every 6' across the back wall near the work bench and every 10' down both sides. I have a big old refrigerator by the front door to keep drinks and snacks so I don't have to walk to the house (almost 50' away!). I put in one 30AMP plug for charging rv batts. You may want to consider installing heavy gauge outlets for other considerations; 220 portable heater, vehicle lift, maybe a compressor, etc. Be sure to get everything in writing before you committ to any construction unless your're doing it yourself of course. Some builders and their associates will think they have a better plan than yours and may suggest "subtle" alterations that can add thousands to your costs. Before any materiels are ordered be sure you know what they are, where you're going to unload them and how much you're paying for them. You'll have to store your materiel outside so buy insurance on those materiels that will lapse when the project is completed. I wish you luck. We travel out west frequently and I have often told DW if I had my choice (and we could afford it), we'd have a house in Colorado.