Guide to house extension costs

money_saving_fan_3

raybould wrote: »

hi can anyone give me an idea on the coct of a single story extention on my barn conversion.. with a pitched roof.. dims are 5m x 4m . i only want the shell and floors..

We have just had a single storey extension with pitched and tiled roof built on our bungalow in Norfolk ; dims 4m by 7m externally : basic contract cost with electrics and plumbing; to provide own bathroom and decorate ourselves came in at just under £30000. Adding extras such as extra plastering coving new mains water and tank in loft plus bathroom fittings, flooring, pathway outside, decorating etc it came to nearer £40000 in total by the time we had finished.

chatterboxwillie

I think I may have mentioned this before but there are plenty of instant quote sites out there where you provide a bit of information about what you want doing and then local companies battle it out for your work. What this means to you is a) you don't have to worry about the effort of ringing around b) these people PAY for the chance to quote for you so they're generally going to be reputable companies and finally c) you get the best deal as they know they're competing directly with their main competition. I recently filled one in for a replacement garage door. The quote came back half the price of the people I rang just a week before. It was fitted within 3 days and is perfect.

There is a site that one of my friends used before - bespokeconservatoriesuk.com (can't make this a link i'm afraid)

It's all very self explanatory really but you pop in what you want doing and then you'll get a call within a couple of days.

QS_the_best

If you choose to pay the cheepest price be preperred to get a cheap, sub standard job. Good builders have to charge alot due to paying very high insurance costs, the extra costs on top of labour, including the cost of vans, office, tools, profit and tax. They also have to burden the cost of peolpe getting a stupid amount of estimates, these take alot of time for the builder and time costs money. So the rule of thumb, if you want cheap, buy a trabant, if you want quality, pay for a BMW. What you save in the short term, may cost you double in the long run.
Hope this helps.

Sarahmichelle87_2

QS_the_best wrote: »

If you choose to pay the cheepest price be preperred to get a cheap, sub standard job. Good builders have to charge alot due to paying very high insurance costs, the extra costs on top of labour, including the cost of vans, office, tools, profit and tax. They also have to burden the cost of peolpe getting a stupid amount of estimates, these take alot of time for the builder and time costs money. So the rule of thumb, if you want cheap, buy a trabant, if you want quality, pay for a BMW. What you save in the short term, may cost you double in the long run.
Hope this helps.

Sorry to state the obvious but I would just like to say, in response to the above...
Work with your architect / consultant / appointed professional and go through a tendering process. Choosing the most competitve tender doesn't necessarily mean that you're going to get a lesser quality job, otherwise there wouldn't be any point in the tender process at all.
You just need to check and double check that the specification has been properly followed, and all builders are quoting for the same works.

Obviously be mindful that if the lowest tender is substantially lower than the others, you will need to go through it in a lot more detail to find out where costs have been cut.

Yes, ultimately as a rule of thumb you get what you pay for, but that doesn't always mean its sensible to pay the highest price for everything! Shop around!

Outer_space

Hello, spend all day working out costs for proper building works and find it tiresome when people ask for a price of an extension then wonder why I cannot just tell them

It's similar to asking how much is a car!

Or how long is a piece of string,?

We done many extensions at sub 700 per sq meter and one recently that was a mear 10 sq/m for 50k, it all about the detail! The devil is in the details.

Does it include drains, deep foundations, easy access, expensive bricks, cheap tiles, small windows, an existing knock through to the main house, or twenty sockets and five radiators, new boiler, planning permission, building control inspections, scaffolds, oak stairs, mdf skirting boards, new bathroom or cloak room, hans grohe shower, moben kitchen, karndean flooring etc etc etc

These all have a cost - bricks are 18p or 78p or more. How many do you need? Is it brick and block or timber frame or is it block and render or tiles hanging, details details

damonthebuilder

People often confuse cost with value for money.
I quoted a guy for his extension back in March - all in all 12 pages detailing everthing I had included for.
On my advice he sought several other quotes (6 in all) 2 were ridiculously expensive, 1 was ridiculously cheap. Myself and another were 800 quid apart, but the one he chose to go with was 10k cheaper and not VAT registered (how does a builder that's been trading for a few years and does a 50k extension every 4 months get away with not being VAT reg'd?) and whose "quote" was a handwritten (okay it was on headed paper) single page document with a price at the bottom of it.
The customer wanted the job started at the end of May and completed by the end of August - and guess what? still going... might be finished by the end of September...might be...

JD_Developments

shona wrote: »

Does anyone have an idea of a ball park figure for an attic conversion per m2? Will need beams moved as are W shaped at the moment.
We wouldn't need a dormer though as there's plenty of headroom - velux windows would do.

an average loft conversion would cost around £8,000 all in

ArchitectEDIN

I agree with Damonthebuilder, as an Architect I see people choose stupidly low tender prices and pay dearly in the long run. It can be hard to estimate house extension costs, particularly at the first meeting with a client, so I started publishing a guide to likely costs and timescales on my website

Unfortunatley, as a new member to the forum I cannot post a direct link, however if you click on my profile my homepage is there, just follow the link to Architects Fees and then to House Extension Costs.

This info is based on my own experience and in my view is a minimum cost. If your builder is charging less, there will be trouble.

As for attic conversions, they are far more complex than most people realise. Do not start unless you have a minium construction budget of £30k + VAT

MatthewGaskin

A similar story from me...
We want to extend above our existing garage/kitchen but are getting silly-money estimates from builders.
We've got planning consent and the foundations are already up to the job but for a pretty simple 8m x 3m box all the South Oxfordshire builders we've contacted seem to think it'll take £50,000! Does anyone here know of a good builder who doesn't want lottery-win-sized profit margins on a job?
Many thanks in advance.

mr_skinflint

ArchitectEDIN wrote: »

I agree with Damonthebuilder, as an Architect I see people choose stupidly low tender prices and pay dearly in the long run. It can be hard to estimate house extension costs, particularly at the first meeting with a client, so I started publishing a guide to likely costs and timescales on my website

Unfortunatley, as a new member to the forum I cannot post a direct link, however if you click on my profile my homepage is there, just follow the link to Architects Fees and then to House Extension Costs.

This info is based on my own experience and in my view is a minimum cost. If your builder is charging less, there will be trouble.

As for attic conversions, they are far more complex than most people realise. Do not start unless you have a minium construction budget of £30k + VAT

The link to your website quotes 60-70K for a two storey rear extension. I'm in Yorkshire and you can get similar for 40-50K. Why are Edinburgh prices so high in comparion?