Petra - the development budget doesn't include the purchase of the site - because otherwise it'd make me cry.
Fran - 10% contingency included - to keep costs down I'm doing a lot of the work myself - groundworks, preparation, drainage, demolition, removal of roof and timbers, replacement of roof timbers, fitting out inside etc etc etc.
Not electrics or plumbing though
Living in a cottage about 1/3 of a mile away. (It's frucking feezing here today with about a foot of snow, so I'm hiding indoors)