How wide should a double car garage be to allow the doors to open?

Answer 1

The 2004 Hummer H1 is 86.5" wide.

It is probably the widest production car out there.

Therefore, it establishes a suitable maximum for garage size.

I figure the doors are probably at least 4' long and must open to a 45 degree angle to be useful. So, sin(45 deg) = door_clearance/48" => door_clearance=34".

Therefore, to have two Hummer H1's standing side-by-side with both doors open to 45 degrees, one needs at least 2*86.5" + 4*34" = 309" = 25.75'.

Allowing for a little room on the sides to hang equipment. I would say that a garage would have to be about 30' wide.

Of course, planning for the widths of a normal sedan, say a Nissan Altima (70.7") would save you 32" and make the garage about 25-27' wide.