Sorry Mags, I did mean too!! Some home rescues have pens in gardens, so they never meet resident cats. I personally have my spare room for fosters, at the moment it is just one big room, but I do keep toying with the idea of having some kind of cages put on the walls. They are in isolation for 2 weeks (although sometimes longer, Rolo was 3, and mum's dont come out till all the kits have been rehomed and they are spayed, think Bella had about 5 weeks in teh cat room last year before being allowed out. Any unneutered toms that come aren't allowed out till they have stopped smelling, to help with the smell). They are then allowed about an hour or so out, unless of course they show signs of major issues, then they are quickly put back and they stay in there till they are rehomed (only happened with about 2 cats so far, others have chosen not to leave despite the door being open though). IF they are here after a month, with no issues, then I start to leave them out longer and work up to leaving them loose in the house all night. Cats like Rolo and Moses who have been here months are allowed outdoor access (well, Rolo gave us no choice, I tried to hold off with moses, but wasn't fair cos the other 4 were allowed outside). I do also use my bathroom, quite a few cats have lived in there, I prefer that for older, less active cats though, as they dont have the space, although the first youngster to use that room utilised the bath as extra play space, that was fun in the morning, you had to work out what was in there before you could shower. i do have a dog cage, but this rarely gets used, can only remember 2 fosters actually going in it, although I think a third has, but I cant remember who that was. I have learnt the hard way what my numbers are, but fortunately being part of a group there are others who can hopefully help when I am full.
i am also lucky that Molly is an ex-foster, so has only ever known cats come and go here, and she lives in my bedroom, and doesn't allow many cats to share her space, so it does give me more space for fosters downstairs.