cellar conversion.. how much £?

emma_b_4

hi, my OH and i are playing with some ideas at the moment, either moving or doing sum work on our current home with the equity we have. we have a low mortgage, well in todays climate anyway !! 49k on a property worth approx 105k.
we are considering converting our cellar as it is huge, the siz of the house (some of the neighbours cellars have bben blocked off, some of other neighbours use it as their kitchen)and is split into two rooms we use one as a utility room this side had floor down and apinted walls the other side just has a big sheet over floor, theres no concrete or anything down so we dont use it for anything and it is this side we would do work on.
at the back of our house you go down steps to garden, this cellar room is garden level so would look great with french doors, opening out straight to garden.
we have never done anything like this before and have no idea what the costs involved would be. OH is quit handy and has friends who are in the trade so thing like electrics would be at cost price, but building work would be full price!!
has any1 ever done a cellar conversion? the ones i have seen on the net are very posh ones, like swimming pools etc in london, we are in west yorkshire. would use the cellar as a second reception room, maybe playroom when we have children.

thankyou in advance!!

emma_b_4

ps there is already power down there , in form of lights !

emma_b_4

to be more specific, we would need to board out the ceiling with plaster board, put a door or window in and do the floor. possibly dampproofing..cellar is dry but do you have to damproof anyway?