We live in a bi-level. Out back we had an above ground pool attached to the deck and house. It exploded 1 year and a half ago so we have sealed off the whole surround of the deck and since there is nice sand where the pool used to sit, the goats now have a lovely, large pen and we can see them meandering about in the pool area.
Under the living room there is a spot where the house juts out. We simply a 8x6 portion, put up studs and cheap OSB (board) and we now have a cute little goat house right under our living room and attached to the deck. We basically just used the space we had and sealed it off and plopped the little ladies in there. It has worked out WONDERFULLY. I milk in the garage so now they don't poop on the milking stand.
You can be creative with what you have. Take inventory of where you want them, how far you want to walk in bad weather and where you have water and electricity available and work within those parameters.
BTW, we did all of that (wire around deck, goat house, goat bed) all for about $300 so far and I'm estimating high. We just made use of structure we already had. I'll post a picture if you are interested.
I agree with calgal98, you can do a lot more than you think.