When keeping pets that live in terrariums or aquariums, it's common to consider the minimum amount of space they need in their enclosure in order for the animal to be happy.
I was wondering if there was a similar kind of guideline for cats?
I did find it mentioned in The Cat Fancier's Association website that their minimum size of a cattery for a single, 4 pound, cat is 30 square feet.
Is there a guideline for how much space a cat needs to have if keeping them in a house/apartment?
This depends in large part on the complexity of the environment. If the cat has lots of corners to explore and interesting paths to take between them, most spaces that aren't claustrophobic for humans will be okay.
If you're concerned, you can let the cat use more vertical space by setting up shelf systems or furniture to give them climbing paths; there are some systems marketed for the purpose but you could probably look at catalogs for those and figure out a homebrew version. Mine found their own routes to the tops of a bookcase and file cabinet in my office ... This also gives them a bit more opportunity to exercise.
