2) Clear out all the debris from the roof and interior partitions. Now you have an oversized city lot surrounded by a high brick wall (probably with a nice big arched entry way) and a nice concrete slab under the whole thing.

3) Build rooms around the perimeter using stuccoed straw bale construction (see http: //www.strawbale.org). Very cheap, very warm in winter, cool in summer and you don't need to build a foundation because of the existing concrete slab floor.

4) Waterproof the courtyard walls to the interior floor level (2 feet or so above the slab leaves room for a crawlspace and is deep enough for a decent garden). Break holes in the concrete of the courtyard in places where you want to plant trees. (Small trees, of course. Fruit trees espaliered on a south facing wall would be nice). Fill with topsoil (quite cheap, don't need to worry about lead contamination as on most urban lots with pre-1978 structures) to the level you waterproofed to.