House extension costs

Soldato
Joined
17 Jun 2009
Posts
7,089
Location
Swansea
Just wondering if any1 here has recently or previously had an extension build? I have planning permission ready to go in for a 4m x 13m 2 floors extension.

How much have you guys paid and what size extension have you had? Want to get a rough idea of the average price.

WELL I WENT AND DID IT!!! Altho please excuse my stupid 4mx13m (now idea why i said that haha!)

Total cost:

Extension = 38000
New Combie + Plumbing = 3000
New Kitchen = 5000

Due to complete in 5 weeks. Roof is going on today.








 
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Just wondering if any1 here has recently or previously had an extension build? I have planning permission ready to go in for a 4m x 13m 2 floors extension.

How much have you guys paid and what size extension have you had? Want to get a rough idea of the average price.

depending on where you are will dictate the cost of the extension. Roughly where i am (angus) an extension will cost around about £1000 per square metre but up in aberdeen direction it will rise to around £1200 per square metre.

You might be able to sound out a few builders to get rough cost estimates from your planning drawings but more than likely they will want a set of Building Warrant drawings so they can give you a more accurate price. :)
 
No one can answer that its like how longs a bit of string, get plenty of quotes.
 
wow thats big, as DM said its hard to say, a lot depends on location and spec but I would think 100k+ for something that big
 
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£1200 per sq/m would be tight these days I think, that was fine like 8 years ago. Extension cost more as it is more complicated than a new build. You got to take down part of the existing, connect the new build to match, possibly and likely to move drains and electrics and even manholes.

An architect might take 8% fee on a new build but he would take 10% on an extension as it is more difficult to do.

Budget for £1300 to £1400 per sq/m and then double it (2 floors).
 
Thats a big extension, cost will be dependant on lots of factors with what will be in it being key if it has a kitchen and a bathroom then the costs will go up a lot. If I were to pick a number out of the air for a finished product I'd say you looking at at least 60k.
 
I’m in work atm so cant take pictures, the up shot of it’s my dad’s house he has planning permission on there which is practically the size of the current house. My mum past away 2 years ago so Dad is looking to down size. We have £30,000 in savings and room to extend the mortgage.

My dad is a Carpenter so all we’re really after is just the shell aka the block work. I’ve looked on the net and seen the average price is £600m2 for shell only which puts its at £31k? The entire room partisan’s etc minus materials we’ll do ourselves. Lucky my best mate is a corgi reg’d plumber and my uncles a qualified electrician…. It’s just the block work I need done.

I’ve given the sizes to a few builders and am waiting for quotes, I’m just impatient tbh and doing a little research at the rough cost others have paid. I know its impossible to say with the limited info I’ve given but am new to all this malarkey

£100k sounds a bit ott, we’re expecting around £50,000 all in.

This is the plot from above (excuse the bad red circling of the property.#

EDIT the extention will be set back due to front drains.
5uidc5.jpg
 
£1200 per sq/m would be tight these days I think, that was fine like 8 years ago. Extension cost more as it is more complicated than a new build. You got to take down part of the existing, connect the new build to match, possibly and likely to move drains and electrics and even manholes.

An architect might take 8% fee on a new build but he would take 10% on an extension as it is more difficult to do.

Budget for £1300 to £1400 per sq/m and then double it (2 floors).

The planning is already in place and was previously accepted, my dad is also an architect who put the plans in originally.

It will not need anything like a new kitchen, bathroom, much plumbing etc…

It will be 2 rooms down stairs new living room and dinning room. Up Stairs will be master bedroom with walk-in wardrobe and rear bedroom my new computer room (yes it will be big).

So 4 basic rooms plastered, 4 radiators, electrical points and windows.

I’m getting an extra 10% on what ever the quote is just as a back up
 
But you're making it bigger...!

edit: ...Or are you just extending it to sell, and then moving somewhere smaller?

I’m swapping housing with my dad, his house has planning permission hence us swapping.

We are extending for us to live there, 2 kids both will have double bedrooms, my wife and I get a big master bedroom and I get to keep my computer room haha
 
I’m swapping housing with my dad, his house has planning permission hence us swapping.

We are extending for us to live there, 2 kids both will have double bedrooms, my wife and I get a big master bedroom and I get to keep my computer room haha

Until the wife decides it would make a lovely spare room or ensuite!

Have a good think about the layout your going for with such a big extension, I know a massive lounge sounds great and is the easy option it does run the risk of making the rest of the house feel pokey even if it isn't.
 
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Until the wife decides it would make a lovely spare room or ensuite!

Have s good think about the layout your going for with such a big extension, I know a massive lounge sounds great and is the easy option it does run the risk of making the rest of the house feel pokey.

We’ve sat down and set out what we want to do with it, we wont be looking to move ever again, I lived in this house since I was born, so this house is being designed how it suits us, we arent’ looking to sell or anything.

When it all kicks off I’l post up the plans and show you guys.

The fun part is over tho… now the realistic part of the cost :(
 
I really do not think you can get it done or 50k but good luck to you :)

What you are planning is the size of a normal house, dont forget you have to pay VAT on everything as its not a new build.
 
I really do not think you can get it done or 50k but good luck to you :)

What you are planning is the size of a normal house, dont forget you have to pay VAT on everything as its not a new build.

If its more its more, This is why I wanted to post this here. I’m hoping to get a call back today with a price for the shell of it. I’m going to try and use the fact the building trade is on its back side to my advantage.

I understand about the VAT on everything which is why I’ve asked the build to price me with VAT. The biggest cost is going to be the block work as everything we can do our selves minus the material cost.
 
If its more its more, This is why I wanted to post this here. I’m hoping to get a call back today with a price for the shell of it. I’m going to try and use the fact the building trade is on its back side to my advantage.

I understand about the VAT on everything which is why I’ve asked the build to price me with VAT. The biggest cost is going to be the block work as everything we can do our selves minus the material cost.

Are you going to do the roof as well, so this is strictly brick on outside, block inner skin is that right?
 
Are you going to do the roof as well, so this is strictly brick on outside, block inner skin is that right?

Yes. The roof trusses we'll fit, however i've asked the builder to price in the roof titling, fascia work and ofc the foundations

That and the inheritance tax dodge, nice one :)

Capital gains is the correct term if i'm not mistaken? All being done above board... we've done our research and wont tax dodge.
 
I still cant see you getting that done for anything like 50k i think me and Dr House use the same builders :D

Good luck though, great project.
 
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