It's not something any of us can easily change, short of moving home.
So, I guess there's value in a topic related to how we can best use the physical space we have and how to use it. [#1]
I'll start with the thought of what to store if you have absolute minimal space. Water? Tins of food? Maybe camping equipment instead? Maybe you only have space for one choice?
If sealed in a small home, then would you want to rely on the taps working and be happy with your ample supply of stored food? Or would you anticipate needing to rely on stored water which took up all the space you could have used for food? How do we plan for totally conflicted scenarios? Beats me, too.
We don't know the answer, because we don't know what we are going to face being short of. [#2]
I invite suggestions for making the best use of the physical volume available to us. Nothing off the table as far as ideas.
My starter for ten..... Just musings, which I will add to if the mods indulge me
[#1] Survey your space. Look for unusual, usable volume. That might be under the bed, behind the sofa, between the joists under the floor, on top of the wardrobe, behind the kick panels of the kitchen units. Estimate what best would go where. Remember that food and water are heavy and that tonne of tinned food on top of the wardrobe might be a bad idea.
[#2] Assess likely needs. If you live next to a river, do you need to store much water. If you live over a supermarket do you need to store tinned beans?
[#3] Allocate the available space. Have a place for everything, but with consideration of how to access your stuff. If you plan any sort of stock rotation, how will you get to your stuff under the floorboards etc?
[#4] Think outside the box. Can you rent a lock-up? Store stuff with nearby family as a sort of resupply post?
I hope we can collectively come up with some ideas for optimising whatever space we have.