extension costs shell only

[jamiecharlotte]

hi i'm having a single storey side and rear extension it basically forms an L shape down the side of the house and across the rear totalling 57sqm. All i'm looking for is a shell block and render with sloping roof 2 windows one bi-fold 4 roof lights ceilings vaulted. no plastering no electrics no plumbing. i've had 4 quotes but there is a 20k swing from lowest to highest. Anyone know what this should be costing in midlands.
thanks for any help.

 

[clubb699]

Alright bro.

I have had a quote from 1 builder £16K fully finished room plus bathroom onsuite all on the side of the house Thats a 8ft x 7M in total i will probably do some of the inners myself to bring price down

Had another builder turn up but never come back with quote frigging hopeless i say

Will get a few more quotes soon

clubb699

 

[freddiemercurystwin]

I'd think you'd be in the realms of £40-50K maybe bit more.

 

[noyk]

Couldn't you build a whole house shell for 40-50k?

 

[freddiemercurystwin]

Yea, a small one that was about 50m²!

@ the OP we assume you have had Building Regs drawings drawn up and these are what your builders have tendered on? Even so its not that unusual to get a prices varying by 25% or more.

 

[noyk]

Here is a comparison i found a while back between masonry, timber and sip construction costs. Superstructure costs are in the region of 40-45k for 103m2 house.

http://www.sipbuildingsystems.co.uk/files/Build It Green_Cost Comparison Study.pdf

 

[freddiemercurystwin]

But that's SIPS and a new build though isn't it?

Jeez we can only give rough prices what is this, bleedin mastermind!

 

[swanny65]

Couldn't you build a whole house shell for 40-50k?

Agreed - £700.00 a m2 seems a bit steep.

I've just built a 8m x 6m treble garage and am starting on a 6.5m x 4.8m extension combined with a double garage conversion. I admit I am doing a lot of the basic labouring and buying the materials myself. The tradesmen are on day rate. I expect to get the complete job done for £30K.

 

[^woody^]

Anyone know what this should be costing in midlands.

It should be costing whatever the builders have quoted you

There is no "should be", as every builder has his own pricing, expenses, and costs, so there will always be variance

You will pay a premium for a shell only in any case as the builder is not going to be making any money on internal fit out

 

[noyk]

Why a premium? Surely a builder will quote and build on shell only basis, the internal fit out is nothing to do with them so why should they have an interest in making money out of it...

 

[RonnyRaygun]

Couldn't you build a whole house shell for 40-50k?

Agreed - £700.00 a m2 seems a bit steep.

Sounds about right to me. Don't forget with a single storey extension you've still got all the foundations to do, and a whole roof. The price comes down per m2 when you add a second storey as you've only got to add the walls and extra floor.

 

[^woody^]

Because if a builder has a cheap plasterer, and a cheap electrician, and a cheap carpenter, and can get kitchens for half the cost of anyone else, then he can make big mark-ups in the overall cost of the job.

He might make 5% on the shell and 30% on the internals say, and so his overall profit relies on doing a complete job

 

[noyk]

So thats only if you employ a "general builder" and it would therefore be better for the the OP to employ independent trades?

 

[^woody^]

No, employing individual trades could potentially increase costs and increase risk, as then there are the inevitable disputes when work from one trade conflicts with another

Only employ individual contractors if you know how to manage them and the work properly, and each contractor is clear about his role and the work programme, and who is responsible for what

 

[noyk]

So reading between the lines, from what you've said, if you know how to manage things and organise work and people its logical to conclude that you can reduce costs, perhaps not to the extent a good pro would be able to (due to discounts) but otherwise it would be worth it.