I went to a great salon in Leicester with blanch and shock (food artists of banquet courses cranachan and sea spaghetti fame) to talk about repurposing spaces. They put together a toolkit document with practical advice for people converting buildings and putting on artistic and theatrical projects in them which you might find interesting to read.
Here is it:
http://www.blanchandshock.com/Repurpose_Space for the Arts.pdf
Edit: I fixed the link for you. --Mike