[Tenrocca]

Ive just installed a 4 poster. My garage ceilings are approx 2.9m, and with this I get 1.6m clearance underneath with the windscreen about 20mm off the roof. Im cutting a pocket into the ceiling to give me the extra 200mm so I can go to the max lift on my hoist and I can walk under without bending (1.8m). So your looking at about 3.2 ceiling height to be safe.

Big is better when it comes to sheds. I did mine in a double garage...just.