Estimating cost of an extension on potential house purchase?
Estimating cost of an extension on potential house purchase?
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MesoForm

Original Poster:

9,504 posts

291 months

Monday 10th March
quotequote all
We're looking at new houses and a couple have come up that would suit us, one significantly cheaper than another but we would want to add on a double garage and probably a utility room too. How would we go about getting a rough estimate (to the nearest £10k) when I have no idea about building costs?

This is the house
https://www.rightmove.co.uk/properties/159197504
We would add a corridor / utility room off the kitchen / diner leading to a double garage but I can just pick a big number (say £80k) but have no idea if I'm even £50k near!

paddy1970

1,119 posts

125 months

Monday 10th March
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Double Garage: A basic build with a flat roof could cost £30,000–£40,000, while a higher-end version with a pitched tiled roof and better materials could reach £40,000–£50,000.

Utility Room: Depending on size and specifications, a new build utility room could cost £10,000–£20,000.

gangzoom

7,395 posts

231 months

Monday 10th March
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MesoForm said:
This is the house
https://www.rightmove.co.uk/properties/159197504
We would add a corridor / utility room off the kitchen / diner leading to a double garage but I can just pick a big number (say £80k) but have no idea if I'm even £50k near!
How long is a piece of string.

That's a big house, I suspect your want to so other work to it once you start, so if you guess £80k, double it and than add 10%, put it some inflation/VAT, £200k smile.

skeeterm5

4,269 posts

204 months

Monday 10th March
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If I were try to estimate I would go with something like;

Build cost £2.5k - £3.5k per sq m for build to plastered state
Architect, planning, building control £5k - £10k
Finishing costs down to you but for garage and utility it could easily be £5k

I think that would give a reasonable ball park starting point.

TA14

13,096 posts

274 months

Monday 10th March
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skeeterm5 said:
If I were try to estimate I would go with something like;

Build cost £2.5k - £3.5k per sq m for build to plastered state
Architect, planning, building control £5k - £10k
Finishing costs down to you but for garage and utility it could easily be £5k

I think that would give a reasonable ball park starting point.
An architect for this job is probably a good idea. The house already has an awkward flat roof extension and a utility room leading to the garage would be at the wrong side of the house to the drive; the natural location for the garage would be next to the family room. For costs note that you'd be digging into the hill so an engineered slope or a mini retaining wall will be required.

worsy

6,215 posts

191 months

Tuesday 11th March
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MesoForm said:
We're looking at new houses and a couple have come up that would suit us, one significantly cheaper than another but we would want to add on a double garage and probably a utility room too. How would we go about getting a rough estimate (to the nearest £10k) when I have no idea about building costs?

This is the house
https://www.rightmove.co.uk/properties/159197504
We would add a corridor / utility room off the kitchen / diner leading to a double garage but I can just pick a big number (say £80k) but have no idea if I'm even £50k near!
Loads of potential that - Could be quite lovely.

ThingsBehindTheSun

2,106 posts

47 months

Tuesday 11th March
quotequote all
worsy said:
MesoForm said:
We're looking at new houses and a couple have come up that would suit us, one significantly cheaper than another but we would want to add on a double garage and probably a utility room too. How would we go about getting a rough estimate (to the nearest £10k) when I have no idea about building costs?

This is the house
https://www.rightmove.co.uk/properties/159197504
We would add a corridor / utility room off the kitchen / diner leading to a double garage but I can just pick a big number (say £80k) but have no idea if I'm even £50k near!
Loads of potential that - Could be quite lovely.
Wow, makes me sick to think that our two bedroom Victorian two up two down in greater London is worth the same as that.

MesoForm

Original Poster:

9,504 posts

291 months

Tuesday 11th March
quotequote all
ThingsBehindTheSun said:
Wow, makes me sick to think that our two bedroom Victorian two up two down in greater London is worth the same as that.
If it makes you feel better it was up for £750k last year which made it out of our budget once you added on building a garage - now it's cheaper I'm wondering whether we can get it all done...
We're viewing it this week so will see how we feel about it after that, as someone above said there's a lot of potential there.

MattS5

2,028 posts

207 months

Wednesday 12th March
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Thats about 5 miles up the road from me.

If you need a name of a decent builder (or a few trades etc) let me know.

Unless of course you're local already in which case you'll already know a few.

Cheers

Neil1300r

5,547 posts

194 months

Wednesday 12th March
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The layout would drive me mad. Two staircases, as it looks like a series of extensions not planned together. Its got 4 reception rooms as well as a kitchen / diner. Pull the front wall out of the room marked lounge and there's your double garage, lose one reception room. Build on top of that, get rid of the corridors upstairs, the second staircase and rearrange the majority of the rooms and their size. There will be room for a utility room up there as well

MesoForm

Original Poster:

9,504 posts

291 months

Wednesday 12th March
quotequote all
MattS5 said:
Thats about 5 miles up the road from me.

If you need a name of a decent builder (or a few trades etc) let me know.

Unless of course you're local already in which case you'll already know a few.

Cheers
Thanks but we're about the same distance away smile


Neil1300r said:
The layout would drive me mad. Two staircases, as it looks like a series of extensions not planned together. Its got 4 reception rooms as well as a kitchen / diner. Pull the front wall out of the room marked lounge and there's your double garage, lose one reception room. Build on top of that, get rid of the corridors upstairs, the second staircase and rearrange the majority of the rooms and their size. There will be room for a utility room up there as well
The layout actually works for us - we both work from home so need 2 home offices plus my wife wants a music room / library. That's 3 of the reception rooms gone.

rustyuk

4,705 posts

227 months

Wednesday 12th March
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You could quite easily spend 250k just on the refurb. Lovely house!

Pheo

3,436 posts

218 months

Wednesday 12th March
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worsy said:
Loads of potential that - Could be quite lovely.
I was thinking the same I’d not worry and go all in 😂

alfabeat

1,327 posts

128 months

Thursday 13th March
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Neil1300r said:
The layout would drive me mad. Two staircases, as it looks like a series of extensions not planned together. Its got 4 reception rooms as well as a kitchen / diner. Pull the front wall out of the room marked lounge and there's your double garage, lose one reception room. Build on top of that, get rid of the corridors upstairs, the second staircase and rearrange the majority of the rooms and their size. There will be room for a utility room up there as well
Our higgly piggly house is like that with 2 staircases. We love it. Kids in one side, us in the other. Gives a degree of separation/privacy. I love houses that are not "normal" :-)

OP that looks like a lovely house with loads of potential if you feel the need. My advice would be to do nothing until you have lived in it for a number of months to see how the house works for you as it is.

Edited by alfabeat on Thursday 13th March 09:58

MesoForm

Original Poster:

9,504 posts

291 months

Wednesday 19th March
quotequote all
Thanks for all the replies - we went to take a look at it and my initial budget of £80-100k would be spent just getting the house to a state we would want to live in - smelt damp and musty throughout even though it's lived it, some cracked windows, that lovely outbuilding isn't so lovely. They are all things that are perfectly fixable but it's too much of a project for us especially as I'm completely incompetent at DIY let alone any major jobs!
It will make a fantastic home for someone with more skill and time with us.

Chumley.mouse

707 posts

53 months

Wednesday 19th March
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Wow looks perfectly liveable to me ……. Maybe my standards are lower than most ?

princeperch

8,122 posts

263 months

Wednesday 19th March
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Things seem to have gotten very expensive very quickly.

Neighbours of mine want a knock through done and a box built at the back of their house, about 6m x 4m, plus install of kitchen etc.

A good few weeks work if not 4-6 months all told.

Getting various quotes of 200-250k and that is with a good supply of willing builders to do the work.

I can imagine your feet will be well and truly to the fire if the supply of potential builders is low due to location. They've got you by the balls potentially.

Juan B

557 posts

20 months

Wednesday 19th March
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princeperch said:
Things seem to have gotten very expensive very quickly.

Neighbours of mine want a knock through done and a box built at the back of their house, about 6m x 4m, plus install of kitchen etc.

A good few weeks work if not 4-6 months all told.

Getting various quotes of 200-250k and that is with a good supply of willing builders to do the work.

I can imagine your feet will be well and truly to the fire if the supply of potential builders is low due to location. They've got you by the balls potentially.
That include a 150k kitchen?

If someone is paying 250k for a 24sqm single storey extension then they are well and truly being had off

MesoForm

Original Poster:

9,504 posts

291 months

Wednesday 19th March
quotequote all
Chumley.mouse said:
Wow looks perfectly liveable to me ……. Maybe my standards are lower than most ?
We thought the same until we went round and looked at it!
Someone good at DIY / amateur building could make it fantastic, but that's just not me.

gangzoom

7,395 posts

231 months

Thursday 20th March
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Chumley.mouse said:
Wow looks perfectly liveable to me ……. Maybe my standards are lower than most ?
Looks like you can sink £200k+ into just internal renovations without trying. Any structural work and double it, the back of the house and the flat roof extension at the front all looks like add-ons versus part of the house.

Knocking half it down would give you a great opportunity to redesign/build something really interesting, its a really nice plot, add in some full height gabel glazing and you can fill the whole house with natural light but the budget will easily need to be £500k.

You could DIY it all, but I suspect it'll than end up been an 'endless' project, and for any major structural changes you will need get the professionals in.



Edited by gangzoom on Thursday 20th March 06:53