bought two of these for our lake cabin built in 1963. Ceilings are low (just over 7') and rooms are 10'x10'. We typically have 20+ people over the 4th of July and only had 3 full beds in addition to the master before. With these bunk beds we doubled our sleeping capacity to 6 full beds. BTW I installed brackets to the wall for stability. I used 1.5" pipe straps and bent to fit then anchored to the wall. My wife and i slept on top bunk and it was very stable. Our combined weight is between 340lbs - 350lbs and these worked great. i don't recommend excessive jumping around/movement at this weight but for just sleeping they were fine. Get some pipe insulation and zip tie to the steps as they are hard on the feet with out it.

Even at the low ceiling height we could sit up on the top bunk as well as the bottom. The bottom bed sits just an inch off the floor.

We used the LUCID 6 Inch Gel Infused Memory Foam Mattress - Firm Feel mattress and they were very comfortable.