How much roughly for an extension over double garage?

[manicmum66]

Hi all, we've put an offer in for a house which already has pp for an extension over the double garage for a big master bedroom with en-suite. We realise that the garage foundations probably aren't strong enough and so the garage will have to be rebuilt. However, a local architect DH contacted today has told us to expect to pay £200,000. That's massively more than we anticipated and far more than we could afford.

If you've had a similar sort of extension done in the recent past, how much was it roughly and how was it project managed? Many thanks!

It depends on too many things (size, access, structural req, finish) to guesstimate but based on an average kind of job that sounds too much.
I did an extension which rejigged and extended kitchen, utility, wc & family room downstairs and added master suite (bed, ensuite, dressing room) upstairs for £70k for a client.
It wasn't particularly fancy but nice neat job.

Meant to say take the plans to 3 builders and get quotes for a more accurate idea of costs for the scheme. They may also be able to suggest cost saving measures which don't have an effect on the planning.

we demolished our double garage and built it again with 2 double bedrooms and two ensuites above it. We actually gained a bit of extra space as the original roof was a chalet roof so imagine space upstairs gained of about the width of 3 single garages!. Also extended the depth ground floor so we had a full garage width utility. Extended kitchen into old utility + 1.5 metres with glass atrium. Full rewire as well. Quotes in east Anglia ranged from £97K to £175K. One year on still lots to do but we are very happy with it as we have gone from 3 to 5 bedrooms.

Thanks very much. Seems my gut feel that £200k way over the top is right. Will ask builders to quote. Cheers.