Our school space is predominantly in the basement. It's our family room (the side of the room you don't see are the bookshelves and television). There is a bathroom nearby so they don't have to go upstairs and get lost on their way to it. The laundry room is down there too so if it's safe to do so, I can leave them to think on their own a few minutes while I put in another load. Additionally the basement contains the master bedroom (a nice alternative work space for someone who needs quiet) and the 3 year old's bedroom. I had hoped that he'd be more likely to play in his room when we were working on our studies, but that rarely happens.
This is how we transform it when we're working on learning activities. The curtain reveals our whiteboard (and one of these days, our cork board). The other curtain is actually a window. The table unfolds to give us more workspace. The drawers in the table contain our whiteboard markers, our pencils/colored pencils/markers, and there is a drawer of things for S to do as well. If we have to move locations we can pull the drawers completely out and take the stuff with us. Having two couches is also a great plus. These kids have no idea what sitting at a desk all day feels like.
The downside is that this space is also our company space (one couch is a hide-a-bed) so we have to move our study space around when we have guests. No problem. With the exception of the whiteboard we are portable.
We store three containers in our laundry room and bring them out when we get started. First, our supply box. Stuff that we usually go looking for, glue, tape, hole punch, stapler, index cards, timer, etc.
Second, our books. This magazine rack contains their notebooks and any library or reference books we're currently using.
Third, our station box. This is where they find their assignments. All workbooks, instruction sheets, read alouds, spelling words, etc. are in here as well as blank paper and a space for my stuff.
When we're done for the day we close up shop, put the containers back in the laundry room, fold down the table and close the curtain. I don't want to live in a school room. But I do want to have everything close by (there is a ton of storage for everything else in the laundry room). This does the job nicely.