Above garage extension costs?

[Jhas]

Hi All,
We are about to put an offer in on a house which has planning permission to put a first floor extension above an existing converted garage. The thing is that the house doesn't suit our needs unless we do the extension but we have no clue what something like that would cost. We're based around Bristol. Has anyone else had the same thing done and if so how much did it cost? The existing house is 3 bed currently.
cheers all
xx

We have quite a traditional 1930s semi with a garage, the kitchen has already been extended behind the garage. We recently started an extension which consists of a three metre deep ground floor extension across the whole width of the back of the house and a first storey extension over the garage and current kitchen. We are paying 38k for that so I would think that just the upstairs would have been about 20k.

That's great info, thanks. I had a similar figure given by my sister who's about to have a ground floor extension with roof top terrace for £15k. It's all looking very promising. :)

Do you know that the garage foundations are deep enough for an extension? Just thought I'd mention!

Is it a newish house? An old garage may not have deep enough foundations for a second storey to be added safely, worth checking. But these days building regs do insist that all foundations are laid deep enough for 2 storeys (as people often add later) so for a modern house should be ok.