Keith... Thanks for the HEADS UP about the enclosed trailer, hadn't thought about that.

Yes, trailer storage is important too.

I laid out my storage garage with a 12'x12' door on the short side so as to park the truck and trailer along the back long wall with room enough to drop the trailer gate. Front side long wall has three 18' doors to allow any car to back out and go. 14' ceiling allows lifts to stack cars. "attic trusses" allow for parts storage room upstairs, accessed by staircase and a hoist on a jib through a scuttle hole for heavy stuff.

Attached to the house, the 28x30 shop ajoins the driver garage and then extends to a "dirty room" with parts washer, blast cabinet vac, a small paint booth and the compressor. On the frontside of this also ajoining the shop is a garage for the tractor, ATV, fork lift, engine lift, and the blast cabinet which is connected to the vac through the wall. 2" foam under the concrete which is 8" thick in lift mount areas and radiant water heat. You will want floor drains also.

That's beautiful property and it's satisfying to have a plan come together with everything at home, I was exactly where you are three and a half years ago. Hire contractors based on quality rather than price and good luck!

Bill W

RE : Trailer. Build it such that you can pull the trailer all the way through, so you go in one door and out the other. You don’t want to have to back trailers up if you can avoid it. And make that pull through area wide enough that after a long trip or inclimate weather, you can pull the whole trailer and truck inside and shut the door. And the door high enough that a rollback can haul something through the door.
RE: Ceiling. Make the eave higher than 12’. You may want to make a loft and you will be ducking rafters if you only have 12’ and are of average height. A minimum of 14’ to the eave. Keep the building clear span. If you do make a loft and you plan on putting vehicles under the loft floor area, then you will want an engineered clear span floor truss, so no supporting poles are in the way. If you have no plans for a loft, consider having roof trusses made that have the center of the span open. With this approach you would want the doors on each end in the center of the gable. You could build a much shorter side wall and gain several feet of clearance in the center with this type truss.
A building within a building. Large buildings are hard to heat and cool. If the majority of the building will be used to store “stuff”, consider walking off an actual work space that is manageable to heat and cool or like having a smaller building within a building.
Read Garage Journal.com thoroughly and and there are some farm magazines that put out the best workshop ideas in a once a year publication. There are a lot of great idas. One I liked is putting concealed anchors in the floor. You take a small (4x4 or 6x6”) lid off and there is a stout “D” ring or eye bolt. You have to have this really secure to steel before pouring slab. That way if you want to straighter something, like a bumper, you can chain it to the floor and secure it to pry or jack something back to shape. Acts like a frame rack.

James, when I built my shop 20 years ago I was limited to a 30'X40'. More space would've been nice but instead I learned better space management skills.
I made a rule to not store parts, engines, trans, or anything unrelated to current work in my shop. You and everyone likely already know this but its my way of taking the side of suggesting separate building(s) or rooms for parts/equipment storage.
Also, FWIW, I'll suggest using in-ground lifts, if they suit your type of work. I installed one simply because I didn't want those awful posts to work around in my limited space. I use above-ground everyday at work and they're fine but the in-ground at home drastically changes the atmosphere in the shop.

Radiant floor heat! Though, I guess it doesn't get THAT cold there in SC.

I am planning on doing waste oil or wood pellet boiler for floor heat -mainly to keep condensation off the cars in the winter -- much of the time it is cold wet and not freezing... which causes condensation on the bottoms of cars.
Plus heated floors gives me one less excuse to avoid the shop. Actually if my feet stay warm I can work 10 hours. I have a high arched foot which makes the top of my foot higher and the laces on shoes restrict the circulation and my toes can get cold quickly.
Until I got custom Lange Ski Boots for snow skiing and Double high wrap plates on my water-ski I couldn't snow ski for more than an hour at a time max, by the time getting off the gondola my toes would be cold.... with waterskiing now days I can only go for maybe 20 min making hard cuts and jumping the wake before throwing the rope... lol been waterskiing for 40 years.

Bentley - I am planning an airlock which a car can drive into without losing my A/C - Heat, however the building within a building is a great idea - how our plant was constructed. 9,000 office inside of a 75k building -

My only advice would be to not build something so big that you won't get your money out of property if you ever have to sell.

I had that two houses ago.

It was wonderful.

Front barn was a 30'x50' former horse barn, with stalls and such.

The back barn was the finished off "race shop" (20'x40').

K

Don't forget about the outside. Build a garage that is aethestically pleasing and fits the acreage and neighborhood. If you ever have to sell it will pay off. Too big of a building or boring square box can look awful. Build something with class.

A guy in my area built a shop that is twice as tall and probably 3 times the size of his house and has 3 huge garage doors out front and it looks hideous. He built it 50 feet from his house.

Like I said hideous looking. His wife has to be ticked.

Morton and similar companies have great looking garage plans.

X2 on Morton. Built one this year I’ll try posting a pic

He needs to hurry up. I got some more cars to store!!! The Z is coming to my house!!