Ha! I cracked it.
I have a climate controlled sever room that I can use as part of a temp office space and they are happy for me to host as many miners as I can fit in there... total cost?
£400 + VAT
I also get a desk with a 70mb internet connection too.... up and down ...for erm.. i dunno what yet.. but something! :-)
You should see it its terribly dis-organised about 100 old ATX servers in there already they don't really know what they're doing which works perfect for me :-)

Now it all goes down to mining becoming harder... how long will 10TH/s even at this low cost be profitable? will we see 10TH/s miners or even 100TH/s miners come to market to meet demand..? will BTC zoom up in value making our little hobby still worth it...