I built an extension to my garage out of what was initially recycled materials. I think it probably cost nearly £300 in extras by the end of the project, but it was still worth it. Here's the original thread http://www.retrobike.co.uk/forum/viewtopic.php?t=157675&highlight=
2 in the old pigeon loft, 1 in my 'in the process of being built' catering unit, a frame in the coal bunker & another frame perched on top of the gun cabinets!
That's more like mine Mike, I'd prefer stumpjumpers solution though.
I have 1 small tool shed with 4 of the kids bikes in, a bike store shed with 3 bikes and a trailer bike in, my main shed 8x6 with 5 bikes in and enough room to stand and turn and fettle. I also have my 2 rider bikes and 2 more of the kids bikes in the house. (I only have 3 kids - my 2 boys have 7 bikes between them)