Your average 5 gallon bucket is about 15 inches tall and 12 inches across.
I built a 16 inch platform for my bed. With my mattress I sleep roughly 28 inches off the floor. I am fine with this but had to build some steps for the dogs. This created a 5 by 6 foot space capable of holding 30 buckets. The under bed storage contains mostly totes right now.
The dogs love lying on footstools pushed against the windows. They sit there all day guarding the house. I am planning a 3 by 5 foot window seat covered with an old piece of foam rubber I picked up by a dumpster. I used to have a couple of old futon mattresses in front of the windows but they were huge and afforded no storage. The new window seat should be able to store 15 buckets and offers additional seating when necessary.
I keep 4 buckets under the coffee table. This could have been sized to hold many more but the rugs are shaken outside for cleaning so you don’t really want to move 15 buckets each week. Four buckets are also used as end tables.
Eventually most of the buckets will be placed in a root cellar but I won’t be building that until this summer.
If you are planning a very small house do not overlook the storage. If you are stockpiling several years worth of food the storage space is essential.