Budget cost for extension

[rikdogguk]

Hi All

I'm looking at purchasing a property in NW England which will require extending to meet our requirements. It is on a great plot / location so we are keen to progress but trying to understand what a budget cost for the works might look like. Not had much luck in finding a local builder who is interested in looking (even with the offer to pay for their time) so would be grateful for any advice!

I have included a very crude mark up below. Essentially the works comprise,

- Adding 16 m2 second storey extension on top of existing single storey (assume no current foundations are suitable). French doors with juliet balcony to side elevation. Knock through door to main house.
- Add new 21 m2 single storey to side with pitched roof
- Replace existing flat roof on existing extension (exluding area which has had the second storey added) with pitched roof, hipped with pitched roof on new side extension.

I'm thinking around £1,750 per m2 to a plastered shell, so £65k plus say £10k for the roof on the existing extension. Is this realistic?

 

[big-all]

Absolutely zero idea but suspect any builder would think "they will never get planning for that" or "not going to waste time on project that may take 2 years to get planning" but purely a guess

have you checked for previous planning applications ??

 

[rikdogguk]

Yes the adjoining property has had a similar sized extension in the past so I am reasonably confident of obtaining planning permission. I’m sure it will be easier to get a quote once I have architects plans and pp but I would like to understand budget cost before purchasing.

 

[blup]

A builder will want to see detailed plans and drawings. Otherwise it's a piece of string exercise. It might not be a bad time to get quotes in the next 12 to 24 months but inflation is a big factor. Better to speak to an architect or plan drawer to see if what you plan is feasible. they might have contacts or be able to give you a rough idea of local prices. A small change in design can add costs or discourage quotes.

Blup

 

[big-all]

a further thought
what was permitted last year is no gtee off anything yes it can help but may simply not be allowed any more but no way off telling without spending money

 

[Loofah]

I'd be using somewhere between 2k-2.5k per new m2 assuming the foundations and rest of structure is sound

 

[Mottie]

I was talking to a builder mate of mine yesterday and he had been asked to give an estimate for a double extension job in the next street to where he lived. He wasn’t particularly bothered as he is rammed with work and he said the plans were a bit rough. He told the bloke that roughly it would be between £95 and £130K. The bloke said okay and could he come round to discuss. When he went there the bloke said "Yeah, I’m going to want this over there and that over there and this here…." My mate said "Hold up, none of that were on those plans you showed me" and he told the bloke to get some proper plans drawn up showing EXACTLY what what he wanted if he wants a more accurate quote. He said the biggest arguments he has is when the client changes things halfway through the job.

Point being, make sure you get a written quote for exactly what you want and dont change the spec halfway through.

 

[cyqi]

If your single storey has no proper foundation, you will probably need to rebuild the ground floor bit too. That is 32sqm plus 21 SQM on the side and total 53sqm. With 1750psqm, you will be looking at 100k as a start + new roof on existing house.