Building cost per sq m?

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Discussion

joshcowin

6,775 posts

175 months

Tuesday 21st February 2017
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BERGS2 said:
Cheers josh - just out of interest - how much do factors such as site accessibility and build type impact on typical pricing?

Our place is/will be rendered block - which the 'tect says should be cheaper, similarly - we're on a flat wide plot with easy access from all sides. are these marginal considerations? Or, could they change things by a few quid per sq m?

our budget is £125k but thats 'all in'

what's happening to insulation costs then?
So the factors you mention do bring the build cost down slightly yes, whats the roofing material?

The access is good, is there room for a skip and/or grab lorries?

VAT will kill you as it does everyone, including the contractors!

I think your budget is good, however I would have a small contingency.

Where are you getting your kitchen from, what worktops are you having, what finished floor? Lighting design and how are you heating the new area? work out these costs as these are the finishes and you do not want to sacrifice these!

joshcowin

6,775 posts

175 months

Tuesday 21st February 2017
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Hereward said:
My 40m2 single-storey oak-frame kitchen extension quote is £3,750+VAT per m2.

Excludes floor coverings and fixtures and fittings.

The oak frame and glazing is £50k + VAT.

The building works are £100k + VAT

I assume this is close to a world record quote.
If you could give some more details? You may have specified materials and finishes that warrant the price, additionally you could be living in a listed building with access through a 750mm wide side gate that cannot be touched/damaged. There could be any number of issues that would add difficulty/work that would up the price.

For a good tradesman/specialist to do the oak frame (just the 50k oak frame) that seems correct!

But for a 40m2 floor slab and strip foundation 100k seems insane!

joshcowin

6,775 posts

175 months

Tuesday 21st February 2017
quotequote all
Fizzsimba said:
037 said:
Not sure why many think that rendered block is cheaper than finished brickwork. It isnt.
When pricing work a builder will go through every aspect of the job from ease of accessibility to ground condition etc then price all material costs then approximate the time it would take in labour then add profit. Then we would divide this by the added extension size to approximate the value per metre which everyone is so obsessed with.
Scaling comes into it as you wouldn't build a 4m2 extesion for just, say £1500 + vat nor would you expect to win a job where you have priced a 200M2 job at £1500 perM2
Couldn't agree more, Every job I price is worked out on an individual basis as no 2 jobs are the same.
Once I've worked out all the variables, Then I will work out its sq mt price if the client wants this.
Completely agree and cannot understand why people find it hard to see that each build is basically a bespoke project. People get caught up on the mete-rage rate due to television programmes and architects guiding them using this method.

TA14

12,722 posts

257 months

Tuesday 21st February 2017
quotequote all
joshcowin said:
But for a 40m2 floor slab and strip foundation 100k seems insane!
How about: under floor heating with marble floors and custom profile oak skirting boards; fancy plasterwork and very elaborate lighting and electrical systems?

joshcowin

6,775 posts

175 months

Tuesday 21st February 2017
quotequote all
In the same post

joshcowin said:
If you could give some more details? You may have specified materials and finishes that warrant the price, additionally you could be living in a listed building with access through a 750mm wide side gate that cannot be touched/damaged. There could be any number of issues that would add difficulty/work that would up the price.

Hereward

4,136 posts

229 months

Tuesday 21st February 2017
quotequote all
joshcowin said:
Hereward said:
My 40m2 single-storey oak-frame kitchen extension quote is £3,750+VAT per m2.

Excludes floor coverings and fixtures and fittings.

The oak frame and glazing is £50k + VAT.

The building works are £100k + VAT

I assume this is close to a world record quote.
If you could give some more details? You may have specified materials and finishes that warrant the price, additionally you could be living in a listed building with access through a 750mm wide side gate that cannot be touched/damaged. There could be any number of issues that would add difficulty/work that would up the price.

For a good tradesman/specialist to do the oak frame (just the 50k oak frame) that seems correct!

But for a 40m2 floor slab and strip foundation 100k seems insane!
Yes, I felt the £50k for oak and glazing was perfectly reasonable.

The building quote excludes floor finishings and kitchen fixtures and fittings - I haven't even thought about those yet.

The £100k ex-VAT covers:
Estimated 20 week project...
Demolition/knock-through of existing kitchen wall to prepare for extension
Foundations and drainage (new drains and soakaway required and moving a soil stack)
Brick and blockwork
Cut and pitch roof, felt, insulate, batten and tile
Strip and re-tile gable end
Insulate, tack, plaster
Screed
Scaffold, skips, grabs, plant hire
Roof skylights
Fibre glass valleys
Plumbing and electrics (wet UFH). Excludes light fittings
Decorate (Paint)
Building Control fees

Site access is good - quiet (unlisted) farmhouse, plenty of storage and space to move, although you cannot get a lorry to the kitchen - the last 60 metres will need to be man-handled or digger/mini-crane.

It's a premium project with a premium price.

joshcowin

6,775 posts

175 months

Wednesday 22nd February 2017
quotequote all
Hereward said:
Yes, I felt the £50k for oak and glazing was perfectly reasonable.

The building quote excludes floor finishings and kitchen fixtures and fittings - I haven't even thought about those yet.

The £100k ex-VAT covers:
Estimated 20 week project...
Demolition/knock-through of existing kitchen wall to prepare for extension
Foundations and drainage (new drains and soakaway required and moving a soil stack)
Brick and blockwork
Cut and pitch roof, felt, insulate, batten and tile
Strip and re-tile gable end
Insulate, tack, plaster
Screed
Scaffold, skips, grabs, plant hire
Roof skylights
Fibre glass valleys
Plumbing and electrics (wet UFH). Excludes light fittings
Decorate (Paint)
Building Control fees

Site access is good - quiet (unlisted) farmhouse, plenty of storage and space to move, although you cannot get a lorry to the kitchen - the last 60 metres will need to be man-handled or digger/mini-crane.

It's a premium project with a premium price.
Obviously I haven't seen this project but with the list of items above I would say that's a realistic price.

I am guessing the bricks (small amount due to frame) will be second hands? These can be up to £2 per brick!

What sort of company has quoted for it? Sole trader or Ltd company?

pete

1,586 posts

283 months

Wednesday 22nd February 2017
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As an extra data point, I've just had a new 20m^2 single storey extension built on the back of a Victorian semi in Windsor. Although the extension was only 20m^2, the work included completely refurbishing another 30m^2 of existing space: new ceilings, wiring, lighting, engineered oak floor, some pocket doors, an internal wall, a new set of exterior French doors - you get the picture.

Including some large (2.7m high!) bifold doors, a big custom window, french doors and a rooflight; £15k on a kitchen; and a new patio and some small external walls, my total spend came to £90k including VAT. The building work on the new extension and the internal refurb, excluding kitchen, glazing, flooring and decorating was £52k including VAT. Access was a factor in the price. I had easy access from a private road through my garage, big enough to get a mini digger in and easy to put a skip directly behind the site. My builder said he wouldn't have been so keen to do the job if access had been restricted.

I throw this in to illustrate that you need to be careful about budgeting based only on a cost per square metre for new floor area, as knock-on changes to the existing space definitely have an impact. Depending which set of numbers you use, you could say I spent anything from £1k (building only for 50m^2) to £4.5k (the whole shebang for 20m^2 of new space) per square metre!

joshcowin

6,775 posts

175 months

Wednesday 22nd February 2017
quotequote all
pete said:
As an extra data point, I've just had a new 20m^2 single storey extension built on the back of a Victorian semi in Windsor. Although the extension was only 20m^2, the work included completely refurbishing another 30m^2 of existing space: new ceilings, wiring, lighting, engineered oak floor, some pocket doors, an internal wall, a new set of exterior French doors - you get the picture.

Including some large (2.7m high!) bifold doors, a big custom window, french doors and a rooflight; £15k on a kitchen; and a new patio and some small external walls, my total spend came to £90k including VAT. The building work on the new extension and the internal refurb, excluding kitchen, glazing, flooring and decorating was £52k including VAT. Access was a factor in the price. I had easy access from a private road through my garage, big enough to get a mini digger in and easy to put a skip directly behind the site. My builder said he wouldn't have been so keen to do the job if access had been restricted.

I throw this in to illustrate that you need to be careful about budgeting based only on a cost per square metre for new floor area, as knock-on changes to the existing space definitely have an impact. Depending which set of numbers you use, you could say I spent anything from £1k (building only for 50m^2) to £4.5k (the whole shebang for 20m^2 of new space) per square metre!
Good informative post Pete!!

kurt535

3,559 posts

116 months

Wednesday 22nd February 2017
quotequote all
All things being equal,

1. Recently finished restoring a 128m2 house which came in at £700m2

New build shortly going up and budgeted at £1300m2. £1750m2 plus vat I'd want gold plated kitchen worktops. Crazy money.

No, i'm not a building company but will project manage and prefer to hire individual trades.

Big saving can also be made by taking over material purchases. Individual trades generally don't like buying the materials so you will need to set up trade accounts and haggle brick/block prices down but it is really not overtly difficult.




skilly1

2,700 posts

194 months

Wednesday 22nd February 2017
quotequote all
Have just built a 32sqm extension, single story but with high roof line with parapet wall and knocked through into 2 rooms. Big sliding doors - 6m x 2.4m and 3 roof lights 2m x 1m.

Building works, plastered out, underfloor heating, electrics and lighting - £32,000
Doors, Roof light Glass, Kitchen - £22,000
Still to do flooring which I have budgeted £3k

This was me bringing in trades rather than using one builder.


kurt535

3,559 posts

116 months

Wednesday 22nd February 2017
quotequote all
Hereward said:
joshcowin said:
Hereward said:
My 40m2 single-storey oak-frame kitchen extension quote is £3,750+VAT per m2.

Excludes floor coverings and fixtures and fittings.

The oak frame and glazing is £50k + VAT.

The building works are £100k + VAT

I assume this is close to a world record quote.
If you could give some more details? You may have specified materials and finishes that warrant the price, additionally you could be living in a listed building with access through a 750mm wide side gate that cannot be touched/damaged. There could be any number of issues that would add difficulty/work that would up the price.

For a good tradesman/specialist to do the oak frame (just the 50k oak frame) that seems correct!

But for a 40m2 floor slab and strip foundation 100k seems insane!
Yes, I felt the £50k for oak and glazing was perfectly reasonable.

The building quote excludes floor finishings and kitchen fixtures and fittings - I haven't even thought about those yet.

The £100k ex-VAT covers:
Estimated 20 week project...
Demolition/knock-through of existing kitchen wall to prepare for extension
Foundations and drainage (new drains and soakaway required and moving a soil stack)
Brick and blockwork
Cut and pitch roof, felt, insulate, batten and tile
Strip and re-tile gable end
Insulate, tack, plaster
Screed
Scaffold, skips, grabs, plant hire
Roof skylights
Fibre glass valleys
Plumbing and electrics (wet UFH). Excludes light fittings
Decorate (Paint)
Building Control fees

Site access is good - quiet (unlisted) farmhouse, plenty of storage and space to move, although you cannot get a lorry to the kitchen - the last 60 metres will need to be man-handled or digger/mini-crane.

It's a premium project with a premium price.
150K? for 40m2 excluding floor, lights and kitchen so, easily approaching 175-180k.

Seriously, consider a few more quotes. You are being staggeringly relieved of your hard earned money.

C Lee Farquar

4,066 posts

215 months

Wednesday 22nd February 2017
quotequote all
I sell ready mixed concrete and a number of our customers have gone to work on sites at £200 - £250 a day. The amount of new homes sites that have started locally is staggering and they are hoovering up anyone who has some idea of which end of the trowel to hold.

Whilst they are earning that well for a hassle free existence it's difficult to tempt them to work for private customers at any price. Of course they don't count the days when they are sent home because it's to cold or wet but that's another story.






037

1,315 posts

146 months

Wednesday 22nd February 2017
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anonymous said:
[redacted]
Not sure why everyone is obsessed with the metre2 cost. Any developer is going to try and get the maximum amount for whatever they are developing. Not unlike any other business. All these fancy cars we all lust after are priced to the maximum the manufacturer can get away with. All affected by competition of course..
House extensions are variable due to the many factors listed in the previous posts. True to say no two are the same so impossible to breakdown costs to M2 to compare.
Building materials have increased substantially recently, labour is short on supply for many reasons. Building costs for domestic work will get more expensive this year IMO.
Not sure where us builders plead poverty, all I see on Pistonheads these days are posts asking if they are getting ripped of or accusations of replying with advice just to show off ( see recent plumbing question )
Paul

kurt535

3,559 posts

116 months

Friday 24th February 2017
quotequote all
037 said:
anonymous said:
[redacted]
Not sure why everyone is obsessed with the metre2 cost. Any developer is going to try and get the maximum amount for whatever they are developing. Not unlike any other business. All these fancy cars we all lust after are priced to the maximum the manufacturer can get away with. All affected by competition of course..
House extensions are variable due to the many factors listed in the previous posts. True to say no two are the same so impossible to breakdown costs to M2 to compare.
Building materials have increased substantially recently, labour is short on supply for many reasons. Building costs for domestic work will get more expensive this year IMO.
Not sure where us builders plead poverty, all I see on Pistonheads these days are posts asking if they are getting ripped of or accusations of replying with advice just to show off ( see recent plumbing question )
Paul
'Not sure why everyone is obsessed with the metre2 cost' - because it works.

joshcowin

6,775 posts

175 months

Friday 24th February 2017
quotequote all
kurt535 said:
'Not sure why everyone is obsessed with the metre2 cost' - because it works.
But it does not, take just one aspect, materials, there is a huge difference in what materials can be used or specified!!

It works if you are comparing apples with apples but each project is usually bespoke.

subirg

717 posts

275 months

Friday 24th February 2017
quotequote all
joshcowin said:
But it does not, take just one aspect, materials, there is a huge difference in what materials can be used or specified!!

It works if you are comparing apples with apples but each project is usually bespoke.
Rubbish. Everyone should have a target budget and the most reliable start point is the £/Sqm benchmark. There will always be variance to this, but to suggest that it should be ignored is just silly. That path leads to massive over spend risk and the potential to get taken for a monumental ride by cowboy builders. The cost to build the shell is highly predictable. The cost to finance to fit out is highly variable depending on what is specified. Get a proper breakdown of all of this from any builders quoting for the work.

One other point to the OP - make sure you have a contract with the builder. I am constantly amazed by how many people blindly get into these substantial projects with no contractual protection whatsoever.

Boshly

2,776 posts

235 months

Friday 24th February 2017
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Factors affecting £/sqft price:

Access
Parking availability
Ground conditions
Level site or sloping
Economy of scale
Single/two//two and a half storey
Basement?
Kitchen?
Intenal walls - ie one open space or four rooms?
Ceiling heights
Bathroom(s)
Build type
Finishes
Location
Contractor workload
Client insitu or clear working space

Other than the above variations £/sqft is very consistent smile

There's a lot of sense being 'spoken' here but a lot of BS also.

As for builders wanting to earn a profit as well as a wage? bds! rolleyes its called risk and reward and overheads. If you only want to pay a wage then organize everything yourself and employ people permanently and on a day rate.

Even the simplest of traders still have to manage their books, invoice for work done, procure materials, carry insurance provide tools, abide by h&S and training (yes I know on that one) provide estimates where if they're lucky they will win one in three AND provide fixed price quotes - i.e. take risk.

So please whilst this doesn't by any chalk mean all contractors are angels/straight/good at what they do enough of the "bds want to earn a wage and make a profit".




joshcowin

6,775 posts

175 months

Friday 24th February 2017
quotequote all
subirg said:
Rubbish. Everyone should have a target budget and the most reliable start point is the £/Sqm benchmark. There will always be variance to this, but to suggest that it should be ignored is just silly. That path leads to massive over spend risk and the potential to get taken for a monumental ride by cowboy builders. The cost to build the shell is highly predictable. The cost to finance to fit out is highly variable depending on what is specified. Get a proper breakdown of all of this from any builders quoting for the work.

One other point to the OP - make sure you have a contract with the builder. I am constantly amazed by how many people blindly get into these substantial projects with no contractual protection whatsoever.
Just to clear up I work for a building company and my main role is estimating (usually conversion and extension works). I have not said to ignore the £/Sqm, I have actually used it as a way of budgeting in one of my responses! The £/Sqm is a good base to start at but it should not be used to commit to a project (i think we agree on this).

I love how you have said 'rubbish' and then gone on to say how the finishes cost is highly variable dependent on spec, as I said materials and spec will vary massively and so therefore will the per m2 price! Oh and so will shell construction methods also foundations and existing ground conditions!

Yes contract and copies of contractors insurance also!
Oh and go and look at previous projects!!


kurt535

3,559 posts

116 months

Friday 24th February 2017
quotequote all
joshcowin said:
kurt535 said:
'Not sure why everyone is obsessed with the metre2 cost' - because it works.
But it does not, take just one aspect, materials, there is a huge difference in what materials can be used or specified!!

It works if you are comparing apples with apples but each project is usually bespoke.
Strongly disagree.

No sane builder/person launches into a new build or refurb without costing it and arriving at price per sq metre.

Of course there is a difference in price due to materials used but you still end up with a price per sq metre - even a high case and low case.

And of course if someone builds on a hillside groundworks could be more than a flat level surface but you still end up with a price per square metre.

Costing a job is not rocket science. Too many people think they can't do it and they can.

i'd also strongly advise people visit their local building merchants. they don't bite and there will be people able to give lots of free advice to you re brick/cement volumes to price off etc.