Not much space is really needed.
Let's see, we won't sleep or have sex, so
no bedrooms.
We eat vegetarian diets pick off the trees or from the gardens; so
no cooking and
no refrigeration are needed -
no kitchens.
Since we won't be watching TV, there will
no need for a living room.
If we have guests,
no need for guest rooms because they don't sleep nor need rest.
We won't need garages, because there will be no cars.
We won't need swimming pools since we will have access to crystal clear, pure lakes and rivers to swim.
We don't need fenced in back yards because we will have meadows, valleys or topical scenes - whatever our dream landscape is.
We won't need closets for clothes, we wear white robes.
I suppose if we really enjoy sitting down and playing a musical instrument, we can do that outside too,
no special room needed, no studio to record.
No doors, no keys, no locks, no one will steal, nothing will rust or decay.
No bills, no credit cards, no money nor stores to buy or sell from. Everyone is equipped and completely content.
No planes, boats or trains - we can fly free at will.
Let's see, how many rooms is that so far? Zero. We don't need a mansion. But whatever He has prepared, I'm good with.