How can I get a ballpark figure for this proposed extension?

[flanagaj]

We are looking to do the same as the below on the property next door.  Existing property will also require total refurb and is basically a shell.   I will do all aspects of the second fix myself, but not sure I have the time or want to risk the delays of doing first fix jobs.   I was hoping that we could achieve it for 200k, but I am getting nervous now, as I actually have no idea.

If anyone can provide any guide or know where I could potentially pay a few quid to get a good idea, then please let me know.

 

image 1 - existing floor plan
image 2 - existing elevations

image 3 - proposed floor plan

image 4 - proposed elevations

 

It's about 100m2 

 

Thanks

Edited October 25, 2023 by flanagaj

[George]

£2000/sqm is the ballpark figure, but you will want a contingency on top of that. 

 

Talking to a QS (quantity surveyor) is the only other way to get a better estimate, but to be useful they'd really need a set of formal construction plans from the architect and structural engineer, in which case you may as well well just create a tender pack and get quotes from contractors. 

[Andehh]

£2500 plus VAT would be closer IMO.

[Buzz]

 

Hi @flanagaj

Are these your plans for your house or something you are considering buying? 

[flanagaj]

1 hour ago, Buzz said:

 

Hi @flanagaj

Are these your plans for your house or something you are considering buying? 

 

These are the plans of the adjoining property and they have made it look really tidy.  £2500 + VAT is certainly not what I wanted to hear, especially, for just a first fix shell.

[Andehh]

Sorry, I missed first fix shell.... My bad! I'd estimate the £2500+VAT  for finished 'basic' spec

 

Yes, £2000 psqm plus VAT (ish) for 1st fix shell doesn't feel unreasonable.

 

So much can be local market dependant though. Online estimators are worth a punt as a cheap QS alternative.

Edited October 27, 2023 by Andehh

[flanagaj]

Just another question on m/2 pricing.  Does that figure still hold for both ground floor and first floor for a double storey, or can you expect to save on the figure?

[Buzz]

24 minutes ago, flanagaj said:

Just another question on m/2 pricing.  Does that figure still hold for both ground floor and first floor for a double storey, or can you expect to save on the figure?

How many m2 is the ground floor and how many m2 the top?

[flanagaj]

11 hours ago, Buzz said:

How many m2 is the ground floor and how many m2 the top?

 

Two storey extension is total 96m2 (48m2 lower + 48m2 upper) and there is a 24m2 section of just single storey which adjoins to the side of the main extension.

It's basically a 12m * 4m two storey and a 6m * 4m side.  

[Conor]

3 minutes ago, flanagaj said:

 

Two storey extension is total 96m2 (48m2 lower + 48m2 upper) and there is a 24m2 section of just single storey which adjoins to the side of the main extension.

It's basically a 12m * 4m two storey and a 6m * 4m side.  

Id allow £2k/m² for the new bits plus £1k for the rest of the house. Think you're looking in the £300k ballpark. Budget kitchens and bathrooms etc will go someway to keep this lower, but hard to reduce the core construction costs.

[Buzz]

50 minutes ago, flanagaj said:

 

Two storey extension is total 96m2 (48m2 lower + 48m2 upper) and there is a 24m2 section of just single storey which adjoins to the side of the main extension.

It's basically a 12m * 4m two storey and a 6m * 4m side.  

@flanagajat fist glance it appears that the architect has been very sensible in not removing any of the exterior walls which will save £££ . 

You have already said you only want a shell so and you want to keep the costs down so I would be getting quotes for the groundwork, bricks and blocks from a general builder including knocking through and making good,the roof and window quotes. This will give you a ballpark number to work off and see if it's feasible financially for you.

You already have some numbers above what others think it will cost but the only way to know for sure is to get the numbers for your project in front of you .

The numbers for our build come with a big false hope alarm attached to them,  our shell which sits on a 300m2 foundation and has 120m2 room in roof space ,including the roof tiles and roof lights all the glass and doors and both drainage systems came in at less than 200k . 

[flanagaj]

The reason I am so confused with all of these figures, is that my brother in law is currently just starting the second fix of his 300m2 bungalow conversion.  (He only actually kept one wall of the bungalow walls, and regrets not demolishing it, eg no vat on new build)  He has used trades people he knows on a labour only basis, and with all first done and just second fix carpentry / plumbing / bathrooms / kitchen, he has spent £220k to date

So you can see why I get confused when I hear 2k / m2 for a first fix shell.  As on those figures, he should be around the 600k mark for where he is at.

Edited October 29, 2023 by flanagaj