I was wondering what the minimum space requirement is for keeping a cat? I was thinking of rescuing another cat and keeping it in my bedroom because my dad is allergic to cats, but it still would be to much for my dad's allergies. Then I thought that maybe I could keep an outdoor cat. I already have two outdoor cats that are part feral and don't like other cats coming into our yard. They will chase away and attack the new cat. I was thinking I could keep a cat in a big contained space outside that separates my outdoor cats I have now. The only problem is, I don't know what size is the minimum. Do you know the smallest space that a cat can live in?
This is my answer to your question. There is no wrong/right answer to this question.
A cat needs a place where it can keep dry and comfortable, some type of house with a roof over.
It needs space to play, and it need shelves to rest and play on.
It needs food and water placed in a protected area, like a place where it is dry and protected from rain and insects and other animals.
A cat needs you and it needs to have you nearby. It needs you to pet it. It needs to curl up besides you when you go to bed, it needs to love you and it needs love. It needs company. It doesn't want to be left alone, but it needs a place to be alone.
A cat needs you to talk to it. It needs to talk to you.
Your cat needs its vaccines and it needs to be spayed/neutered, and if it is living outside it needs to be dewormed twice a year and checked for fleas and lice when you take it to the vet.
A cat needs a cat tree and scratching boards in different places.
The most important thing of all: it needs to be with you a lot, as in all the time when you are not at work/school. It wants to be with you when you are sleeping.
As you can see, I have not mentioned how big the area your cat needs. I know this was your question, but if the things I have mentioned are fulfilled, the cat will have a good life.
If you make the area like 5 by 2,5 meters and 2 meters tall it will be OK. Cats can live in smaller places, but do you want it to?