Garage conversion costs

browneyedbazzi

I'm house hunting and recently saw a house that I like that I'd want to do a bit of work on - mostly quite small DIY jobs with one exception: a garage conversion.

The house has a double garage which at the moment is being used as a studio - it still looks like a garage from the outside with two regular sized garage doors but it has been insulated and a floor put down.

It's a really big space (16' x 16') that we wouldn't really have a use for as it is, so what I'd want to do is divide the garage in two with one half put back to being a garage and make the other half a utility room and office space. We'd have to take up the floor on the half we want to be garage and remove the boarding/insulation that has covered up the garage door on that side and install a stud wall (with a door in it so the garage is still directly accessible from the house) to separate the two halves.

For side that would be utility room/office I'd like to take out the garage door, brick part of the space up and install a window (all subject to planning permission obviously, the window would be the width of the door and approx 120cm high to mirror a window on the other side of the house). I'd also want to put plumbing in for a washing machine and sink - the kitchen is on the other side of the wall so hopefully that would be possible without too much difficulty. There'd also be some units to go in and but those costs would really depend on the units/worktop I choose etc, so for the purpose of this thread I'm just asking about the main building work rather than the fitting out.

Any ideas what you'd expect to pay for this work? I suspect it's relevant that the house is in Surrey, just inside the M25.

I hope that's enough information to get a rough idea but if there's any other information that would be helpful please ask and if I can I will answer (or I'll know what to look at/ask when we go back for a second viewing).