This might get long, but here’s what I did, and things I should have done different! My dad and I build a 60x96x18 shop, and a 12x30 lean too, which is office, and bathroom/mechanical room, back in 2017.
I went with one 16x16 door, one 32x16 door, and on the side wall a 14x16. In floor heat, tankless lp boiler, a floor drain in the center. 10 windows in the shop, 3 in the office, 4 rows of 4, LED lights, and spaced perfectly, so I can add more if I need more light, they are a 3’x3’ lights. 1 service door to the shop, 1 door to the office, see the 4th picture. It is insulated very well, and I can not recall the R value numbers at this time, I think R 25 in the walls, with vapor barrier, and R 49 in ceiling, also with vapor barrier. Don’t hold me to those numbers being exact. You can ask me any questions you want, I know I missed some details!
Now these are things I should have done different. The floor drain being in the center, doesn’t work so well with 3 trucks and trailers parked in it, the center truck is directly over the floor drain. So when greasing, the truck has to be moved forward and back to get away from the drain. Should have put 2 smaller drains in, between the trucks, or put the drain along the back wall, and away from the main area of the floor. I’m satisfied with the in floor heat, but I should have also put in the overhead tube heater for recovery, still could I guess?! I also have a large mini split in the shop for A/C, it’s fine, but I should have put in central air, and that could have also been used as a recovery heat source with a furnace.
Should have priced it 20 tall versus 18, should have priced it 72 wide versus 60, just to see the cost difference. My brother went from 18 tall, to 20 tall on his shop for only $3000 more, and that’s on a 80x112!
I definitely should have went 16 wide on the lean to portion, and 40 long versus 30! Should not have done the awning portion, 1 pole lifts in the winter, and broke apart the sheet rock in my office, and it’s a snow trap in the winter, and corn leaf catch in the fall.
I did not put the in floor tubes in sand, and then do concrete, to have the extra heat storage capacity with the sand. I should have insulted the perimeter 48 inches down, not 16 inches like was recommended by the concrete guy.
Should have put another service door by the sidewall door, but I was looking out for break in access points!
I definitely should have done a septic system, not a holding tank!
There are other things if I think long enough, but the last thing I can think of, the lean to roof line against the shop wall, should have been up higher, and then opened up inside the shop, to use the space above the office as storage, just to have less stuff along the walls.
If you want more pictures, current pictures, let me know, and like I said above, any other questions, let me know, I’ll help where, or how I can! But like everyone says, and it’s the truth, once you build it, and your in it, you’ll wish it was bigger!!!!
My last thought, you said you weren’t doing in floor heat because you won’t be in it everyday. The temp is set at 55* in our shop, and I’m not in it everyday either. I would definitely do in floor, set it at 48-50* and have the tube heater for the quick comfort factor when you are in the building, that way your floor doesn’t crack from no heat, and the floor will have a little warmth for when you do have to work close to the floor!