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Anyone any rough ideas of how much an extension costs?

26 replies

Mamatastic · 17/07/2008 17:53


We live in a 3 bed detached house (moved here last year) which came with planning permission for an extension. It would be two storeys including....

Downstairs: toilet, utility room, family room

Upstairs: master bedroom with ensuite & new corridor (would need to build new walls etc in existing bedroom)

I haven't a CLUE what this sort of extension would cost so I'm just looking to see if anyone has any rough ideas. We aren't looking to do it yet but will in the future if we have any more kids as we need the space. Just thinking ahead!

Thanks )

OP posts:
memoo · 17/07/2008 17:56

we've just had a quote for two story extension. utility and kitchen downstairs and bedroom and second bathroom upstairs. The quote was for £30K but that includes new bath and kitchen, the basic shell of the building was about £20K

brimfull · 17/07/2008 17:56

we had 4 bed house extended

went out 8 ft across whole back of house 2 storeys

involved 3 bedrooms and kitchen and lounge.

cost £50,000 not including decorating

brimfull · 17/07/2008 17:57

not including new kitchen either

sarah293 · 17/07/2008 17:58

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memoo · 17/07/2008 18:00

riven, that seems a bit steep!

sarah293 · 17/07/2008 18:02

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mumwhereareyou · 17/07/2008 20:00

Hi Mamatastic

We had the same but two double bedrooms as you have permission for and it cost us £40,000 all in excluding decoration and new kitchen.

morningpaper · 17/07/2008 20:01

I wuold guess it would be between 50-80k

Tinker · 17/07/2008 20:04

Are these prices being quoted including or excluding VAT? I've heard about £1200 ish per metre sq is a good guide (but don't know if that VAT inc or ex). We're going to have 2 storey extension soon so am watching this with interest.

morningpaper · 17/07/2008 20:13

including VAT

I have had quotes for a 2-story extension (1 bed/1 reception/1 bathroom) which came in at 45k (for basic) and 61k (for complete, but different company) respectively

mumwhereareyou · 17/07/2008 20:29

including vat, builders a bit cheaper here in lincs.

Mamatastic · 17/07/2008 20:46

Thanks for the replies, very interesting. There seems to be a bit of variety but I guess it depends on the amount of space you are extending by and where you live. Will need to start saving pennies!

Can I also ask for those who've had it done, how long did it take from the start of the building work to the finish?

OP posts:
brimfull · 17/07/2008 21:10

Our extension took 3 months,we moved out for 6 weeks when they broke through which speeded up the process a lot.

annieshaf · 17/07/2008 21:20

We have jsut had a double storey extension which included knocking 2 rooms together then extending out to create a kitchen/diner/family room with a bedroom and ensuite above. The building work cost around £40 inc VAT but that didnt include the new kitchen, new flooring or decoration. Extended area was about 5m by 4m on both floors but we did need some structural work doing in order to take walls down. Building work took 9 weeks (again excluding kitchen, floors and decorating.
Hope this helps

Tinker · 17/07/2008 21:27

Oh, annie, that sounds like what we are planning. Quite pleased with (some) of these figures, was expecting a lot higher.

Mamatastic · 17/07/2008 21:38

I'm glad I posted this- I was thinking it would cost a lot more and also take forever!

OP posts:
blithedance · 17/07/2008 21:48

Thanks too. We are looking at something similar and hadn't any idea of ball-park costs.

shilpashelly · 31/07/2008 23:43

I am looking to buy a bungalow which already has 2 double bedrooms converted into the attic. (The garden is massive). I would like to put in a bathroom and perhaps a dressing room upstairs as part of a two storey extension. I have never seen this being done previosly. Does anyone know if it is possible to put extend onto the top floor of a converted bungalow?

Ruthiebabes · 01/08/2008 18:59

In South East it is £1000 a sq metre on average, but often more. We are half way through a ground floor extension across back of house and behind garage. We are paying 45K for first fix, ie need to buy and fit kitchen and decorate (inc tiles, and flooring). This was the most reasonable quote.!!

claricebeansmum · 01/08/2008 19:00

Get a ball of string

Unravel it a bit

A bit more

Then a bit more

Chocolateteapot · 02/08/2008 08:22

Shilpaselly, you can extend out . Ours was built with bedrooms in the roof initially but we now have planning permission for a further bedroom and lots of other bungalows locally have done it. They have to cut into the roof and resupport it which apparently makes it fairly expensive.

MrsMattie · 03/08/2008 17:14

We've just had our kitchen extended. Including fairly cheap kitchen it cost £25k. We're in London, btw.

shilpashelly · 04/08/2008 22:44

Thanks chocolateteapot - when you say expensive do you know approx how much we're talking?

BarcodeZebra · 04/08/2008 22:50

£48k for: new dormer; Window turned into french doors; old extension knocked down and removed and new posh architect designed number built. All in a very hard to reach house with no access to the back except through the house itself. We got a quote from one company for £90K but in my experience builders only quote you silly prices when they don't want the job. (I'd prefer if they'd just say but there you go)

Chocolateteapot · 05/08/2008 07:20

7.5m x 3m to give bedroom, ensuite, breakfast room, utility room, a bit more landing and hall, £40k from one builder. Another said 17k for the shell so I think would work out about 30k.

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