What budget do we need for remodel?

[Remodeller]

Hi all, first post on here so any guidance would be greatly appreciated. We have planning permission to remodel our existing detached house in Essex (approx 1,900 sq ft existing house). We're really struggling with our estimating the costs so I'm looking for some guidance from experienced builders and trades people. Here are a few details;

- looking to add two double storey extensions to both sides of the house (kitchen,dining room,utility room,drawing room, garage, bedroom & ensuite, master bedroom &ensuite)
- Approx added sq footage is 1,600
- Both sides will have pitched roof
- the existing house will have a new staircase, repositioned downstairs bathroom and added ensuite upstairs. Other than this it will be gutted and redecorated

I appreciate that's a limited amount of info to provide specific costs but any rough estimates would be very helpful. I believe we can get that all done for £400,000 to a half decent standard (including preliminaries etc) but I'm being told otherwise.

Thanks in advance for any helpful replies!

 

[longdogs]

Ensuite approx. £1500
Family bathroom approx. £3,000

Plus suite/tiles/fittings etc

 

[freddiemercurystwin]

If you can afford to get £400K worth of work then you can afford to get a QS to do some number crunching!

 

[Dave54]

I know from when we were looking at getting a granny annexe built three or four years ago that there are plenty of online building cost calculators.
Although I'm certainly no QS I'd have thought that surely with £400K to spend you are getting somewhere near to the cost of having a place built as you want it?
Remember that extensive renovation is often as expensive, if not more so, as rebuilding, and that building onto an existing property is more problematical, and hence expensive than complete new build.
If I were you I'd also get used to working in metric units as it saves endless conversion.

 

[Chri5]

Essex? I'd guess at about £1200 per sq m of added floor space for build and first fix.

Finish, well that depends how high end you go, I'd suggest a budget of around £1500 per sq m for the new floor areas and then. Added cost for revamps and stair replacement and repositioning.