Extension - Builder Budget Cost...

[gordon.hunter]

Hello everyone.

I have had an extension designed by an architect.

I stay in Bearsden, Glasgow.

I advised to the architect at the outset that my budget (including VAT) is £90,000.

The house floor area is 150sqm. We are adding 41.1sqm. Totally 191.1sqm

I have attached drawings of the existing building and the proposed extension.

I have been advised it would cost £145,000 with an "incentive scheme" which would reduce the VAT by 50% to make it closer to £130,000. I am unclear on the details of the "incentive scheme"; however that is not my focus at the moment.

So even at £130,000 it is £40,000 over budget.

Features of the build (with reference to the drawings):

Wet UFH in boot room, new shower room and kitchen / family room
Four panel panoramic doors
External - white through coloured render
External - Zinc
External - Western red cedar cladding
External - Composite decking
Velux windows - Five


I would be keen to hear any thoughts you may have. Is this a realistic cost?

Thanks

 

[freddiemercurystwin]

How many other quotes have you had? I've not downloaded your pdfs nor shall I, upload them as images.

 

[^woody^]

I've not got a scooby regarding the local costs, but those look like a proper Architect's design, and if so why hasn't he designed to your budget in accordance with the RIBA Plan of Work?

 

[gordon.hunter]

How many other quotes have you had? I've not downloaded your pdfs nor shall I, upload them as images.

I am awaiting budget costs from two other builders.

Uploaded images.

 

[freddiemercurystwin]

Bonkers, wait for the other quotes.

 

[gordon.hunter]

I've not got a scooby regarding the local costs, but those look like a proper Architect's design, and if so why hasn't he designed to your budget in accordance with the RIBA Plan of Work?

Hi Woody.

Yes they are an architects "concept" drawings. We have not submitted any formal drawings to planning authorities yet.

He certainly has delivered on the design brief but not the cost.

However the budget cost does seem awfully high.

Time will tell when costs are received from another two builders.

Thanks.

 

[gordon.hunter]

Bonkers, wait for the other quotes.

It is not a straight-forward extension of tacking a box onto the back of house.

There is a lot of demolition, putting right and extending I guess.

And I hear more and more that material costs play a part given the difficulty getting them what with the ongoing Corona virus situation.

Apparently insulation such as Kingspan has rise 40%!

 

[^woody^]

He certainly has delivered on the design brief but not the cost.

The RIBA guidelines that he should be following dictates that he delivers on both. It's no good him designing something grandiose that his client can't afford to build - that's a complete waste of time and waste of the design fees.

He should be discussing the design with you and if as designed you can't afford it, he needs to advise where compromises can be made whilst still trying to maintain the generality of the design brief.

 

[domdee]

you've done well to get one quote. I've asked quite a few builders for quotes using them kind of drawings and been told by them all that they cant give a price until detailed reg's drawings are produced. so they can spec all the requirements and price accordingly, e.g lintels, insulation, etc.

 

[Notch7]

Ive done timber orangeries of 40 sq metres coming in around £100k that's Surrey Sussex.

At a real guesstimate I'd say your project could be around that region.

Please bear in mind you have some expensive elements: underfloor heating, bifold doors, composite decking, zinc, western red cedar.

That lot could easily add up to £25k

E.g.:
Top end aly bifold could be £8k
Underfloor heating £5k
Composite decking say £7k
Zinc £3k
Western red cedar £1k

I think you need to get a builder price with these items as PC sums, so you can play around with the budget.

 

[gordon.hunter]

The RIBA guidelines that he should be following dictates that he delivers on both. It's no good him designing something grandiose that his client can't afford to build - that's a complete waste of time and waste of the design fees.

He should be discussing the design with you and if as designed you can't afford it, he needs to advise where compromises can be made whilst still trying to maintain the generality of the design brief.

I selected this architect as he has done many extensions in the area... and to that end... it makes me think the builder is quoting high... otherwise how would he have such repeat business if he was continually off the mark budget wise with his designs.

He has delivered on the design and we just need the budget to fall in line too.

Its not a basic extension. I would say its quite high spec what with zinc cladding, western red cedar, panoramic sliding doors, wet UFH etc etc.

My house is currently 150sqm and the architect has confirmed this extension is adding 41.1sqm so its a sizeable addition.

Moreover there is quite a bit of demolition to be done before building gets underway.

I now do not want to compromise on the build.

 

[gordon.hunter]

you've done well to get one quote. I've asked quite a few builders for quotes using them kind of drawings and been told by them all that they cant give a price until detailed reg's drawings are produced. so they can spec all the requirements and price accordingly, e.g lintels, insulation, etc.

Well those builders need to understand its a budget cost... not a quote that you are asking for. If they were experienced enough they should be able to put a budget cost together for you.

 

[gordon.hunter]

Ive done timber orangeries of 40 sq metres coming in around £100k that's Surrey Sussex.

At a real guesstimate I'd say your project could be around that region.

Please bear in mind you have some expensive elements: underfloor heating, bifold doors, composite decking, zinc, western red cedar.

That lot could easily add up to £25k

E.g.:
Top end aly bifold could be £8k
Underfloor heating £5k
Composite decking say £7k
Zinc £3k
Western red cedar £1k

I think you need to get a builder price with these items as PC sums, so you can play around with the budget.

I have read your post with great interest.

I am inclined to agree with you as regards expensive elements... definitely factors in driving up the cost.

Panoramic Doors - I would say quite as much as £8k... probably more akin to £5k
UFH (Wet) - no idea
Composite deck - sounds too much
Zinc - agree (?)
Western Red Cedar - agree (?)

What wood cladding require little to no maintenance? I dont want to be maintaining it every few years - totally not interested in doing that.

 

[mikeey84]

Just a note on the composite decking- subject to the exact specifications, composite decking can be surprisingly expensive!

Just the decking boards alone can cost in excess of £200/sq m, let alone the structure, groundwork and labour, plus extras like lighting

 

[gordon.hunter]

Just a note on the composite decking- subject to the exact specifications, composite decking can be surprisingly expensive!

Just the decking boards alone can cost in excess of £200/sq m, let alone the structure, groundwork and labour, plus extras like lighting

That does seem awfully expensive for decking but thanks for the heads up