building cost for extension

snowmen

does anyone know what the average price of building an extension on a house in northern ireland is in square metres?

we are toying with the idea of building a double storey extension out the back but need to know a rough ball-park figure first to see if we could even get the money.

I take it a 2 storey extension would be roughly double the price of a single storey extension.

thanks.

Mistral001

About £50-60 per sq ft for a new dwelling the last time I heard. Probably slightly more for an extension as it is smaller and knocking through has to be added as well as generally being more difficult to work on an existing property with regard to access and keeping things clean etc.

motorguy

Mistral001 wrote: »

About £50-60 per sq ft for a new dwelling the last time I heard. Probably slightly more for an extension as it is smaller and knocking through has to be added as well as generally being more difficult to work on an existing property with regard to access and keeping things clean etc.

+1

I would budget £75 a sq ft, bearing in mind also that you will be charged VAT that you wouldnt be charged on a new build.

Mistral001

pgilc1 wrote: »

+1

I would budget £75 a sq ft, bearing in mind also that you will be charged VAT that you wouldnt be charged on a new build.

Good point. The figure I quoted was nett of VAT. There is VAT on extensions.

Milko

I personally think the £75+ figure is still too expensive.
Having designed & tendered quite a few of these over the last number of months, the most recent was for a 550sq. ft. coming in between £25-£28k depending on customers spec. (i.e. tri-fold patio doors etc...) this puts it between £45 & £50ish.
However, no too jobs are the same. As pointed out above, site access, types of materials needed etc... all have a bearing.

polpoo

You could spend anywhere between £60 and £160 per sq. foot it all depends on what your specification is. You also need to consider if structural alterations are required to the existing house, does the wiring and plumbing need upgraded, will you have to relandscape outside when the work is complete. These all add to the costs. You also need to think carefully if you need an extension or if you can shift things around internally to make the house work better for you. Make every square foot really work hard!
If you are going to extend, make sure you get the best possible connection between the existing house and the new addition and also to outside; get as much light into as possible and don't be compromised by existing layouts etc.
Action Cancer run a scheme called Improve don't Move. You get an hours consultation in your home with an architect for a £40 donation to Action Cancer. It might be worth getting a professional opinion about what you can / cant do and also do your bit for charity. Best of luck with whatever you do!

motorguy

Milko wrote: »

I personally think the £75+ figure is still too expensive.
Having designed & tendered quite a few of these over the last number of months, the most recent was for a 550sq. ft. coming in between £25-£28k depending on customers spec. (i.e. tri-fold patio doors etc...) this puts it between £45 & £50ish.
However, no too jobs are the same. As pointed out above, site access, types of materials needed etc... all have a bearing.

You're amazingly cheap if you're able to do a finished build for £50 a square foot including VAT.

The cheapest i've heard EVER in fact.

snowmen

thanks for all the replies.

the extension we are thinking of doing is a 6 m x 4 m double storey extension and a builder has given us a rough estimate of £50K-£55K which could go up or down slightly depending on what materials we end up using.

Mistral001

Is that including VAT?

Milko

pgilc1 wrote: »

You're amazingly cheap if you're able to do a finished build for £50 a square foot including VAT.

The cheapest i've heard EVER in fact.

"finished build" being the structure, doors, windows, plastered out etc...then yes and if its considered amazingly cheap, it would explain why the guys I use are always very busy & able to pay the bills.

I just draw the plans & when asked, price it for the customer

Polly

We finished a 2 storey extension within the last 6 months and it's just fantastic. Our labour costs were lower than budgeted but the cost of materials has soared in the past couple of years and took much more of our budget than anticipated. My advice, for what it's worth, would be to allow at least 30% more than you think the job will actually cost - I wish we had!