I'm planning on a 40X60 with 2 offset 42" Schweiss doors. Metal frame. It will be in a windy and snowy location in Montana. Having doors on two sides means more concrete slab to be poured outside the doors, true. I will only have one SuperCub in it, but plan on renting one side to help offset the cost of construction. One man door is all I want. I don't see the point in windows. I need a place to park my plane, not a man cave. I have not decided on electricity, insulation and heat. Maybe one good solar panel, a battery bank, some LED lighting and a 400 dollar Chinese generator backup. Maybe roof insulation to prevent condensation dripping. No bathroom needed - if I need to pee, the antelope can watch for all I care. Schweiss bifold doors because of the snow, they have a mature, established product, they seem to be the "brand name" of hangar doors, resale value and they do the installation themselves. I'm 66 years old, so not quite "circling the drain" yet, but resale is a consideration for sure. The very hardest and most infuriating thing about this whole process is getting a realistic answer about how much the whole thing will cost.