Guide to house extension costs

harrysahota

The cost has increased since 2006, with materials costing more and Vat increases, overall a basic shell can cost appx £1500 per square meter based on a single storey extension with a flat felt roof.

If a builder isn't registered for VAT or doesnt have the required insurances in place then really you should ask yourself if you want to work with them.

If a builder is good, they should be registered with at least 1 of the main recognised building inststues, I am registed with the GUILD OF MASTER CRAFTMEN and therefore you can instally understand the levels of our work.

When getting a quote for an extension, its not important to have a lengthy quote, I have seen some as long as 10 pages... Whats important is to have an umabigious quote.

Theres no point in getting a quote- which say something like, explore groundworks to eastablish where drainage runs, in order to excavate and make trenches adhering to council norms in order for building controllers to inspect and pass......

when you can say that like me.

Dig foundations.

SO be weary of all the wish wash.

and my last suggestion, alsay see a job that the builder is Currently doing, so as you can see the management of the job/site and quality of workmanship and always go to see a recently completed job... as six months down the lane... bad work begins to show.

I hope this has been useful and its my first post, if you have any questions just ask me and I will try to answer as honestly as possible.

jellyjenny

I'm looking at a lovely cottage at the moment, but it is only a two bed, one being downstairs, and we need at least three bed.
The kitchen is in an extension at the back of the house and we would like to add an extension above that to give us another bedroom. This would have a flat roof-not ideal I know, but we think it would be necessary for planning purposes. We would also like a two story extension to the side of the house to give us another reception room, but more importantly the third bedroom.
I live in the West Midlands, if that is important?
How do I go about finding out if the foundations of the existing kitchen extension are suitable for an extension above?
Can anyone give me a vague idea about how much this would likely cost. We would want it to be block built, not brick. My husband is a plasterer and will render it all. I need a vague figure just for the shell if at all possible.
Thank you

phill99

jellyjenny wrote: »

I'm looking at a lovely cottage at the moment, but it is only a two bed, one being downstairs, and we need at least three bed.
The kitchen is in an extension at the back of the house and we would like to add an extension above that to give us another bedroom. This would have a flat roof-not ideal I know, but we think it would be necessary for planning purposes. We would also like a two story extension to the side of the house to give us another reception room, but more importantly the third bedroom.
I live in the West Midlands, if that is important?
How do I go about finding out if the foundations of the existing kitchen extension are suitable for an extension above?
Can anyone give me a vague idea about how much this would likely cost. We would want it to be block built, not brick. My husband is a plasterer and will render it all. I need a vague figure just for the shell if at all possible.
Thank you

Anything from £5,000 to £500,000

MrPAV

Just had my one done, finished up about two weeks ago actually.

I live in Muswell Hill, so it is a fairly expensive part of North London and does command a half decent house price.

I had an extension on the property when I bought it, albeit a shoddy one that the old girl had built in the 80's. It was a single wall construction and therefore was very cold in the winter, with cracks showing in the wall etc.

I measured the old one, which was 3m x 4.5m and wanted the new one to measure 3.5m x 4.5m.

I called around a few builders and they were asking fair whack (£40k upwards) and the ones that were cheap seemed uncomfortable about references or taking me to old jobs.

After around three months of searching and living in the property, my neighbours (absolute salt of the earth) told me that their nephew had just started up a building firm after working for a firm, so I called him round for a quote.

He was a young chap, only 25 odd, but had been in the building game since the age of 16, initially as a lackey and then working his way up. He had worked on major projects before and seemed to know what he was talking about, was polite and very wary of the fact that we had kids and elderly parents in the house and advised on certain things ie size of bathrooms to make it comfortable for them all and the sort.

He came in with a quote of £29k, which included demolition of the old extension, erection of the new one, moving the bathroom and all pipework into the old kitchen, moving the kitchen extending the gas pipe into the new extension, moving the boiler from upstairs to downstairs and a new fuseboard to house all the new electrics in the new extension. He made us aware that although our living space was going to be around 16m2, the size of the extension was going to be around 21m2, as it would be a new double wall structure with a 100mm cavity packed with insulation to give added warmth. This was with a standard finish, ie no bespoke kitchen, bathroom, flashy granite tiles or the like. He said anything tailor made would be around £5k to £7k more.

I spoke to my neighbours again, who said he really was someone to trust, even showed me baby pictures of him and he was happy to take me to 2 previous jobs. I took the plunge and contracted him, and we agreed to start on a certain date and that I would pay him in 7 weekly instalments. His labourers were polite, efficient, worked very very well and their finish was unbelievable.

7 weeks later, I have a brand new brick built extension which has a fantastic new kitchen/dining area, utility room and bathroom, all for a very reasonable price by a building firm whom I will contract out again for my loft conversion in 3 months time. The shell is around 21m2 and the old kitchen that was refurbished and now houses the new utility area and bathroom is around 9m2. Therefore I have managed to find someone that has come in at around the magic £1000 per square metre number.

There are many rogue builders out there that try their luck but there are also a few diamonds in the rough that provide a great service and are very value for money.

Sorry about the stupidly long post everyone, just thought I'd share my experience.

If any help is needed, please do not hesitate to message me. I work from home so was watching the builders everyday on top of my endless question asking which now means I have a greater understanding of the building process than previously.

Regards

Mr PAV

nic1304

We live in a 2 bedroom end of terrece house with a reasonable sized front garden in essex. We have thought about doing a 2 storey front extension making it 3 bedrooms & adding a downstairs toilet. looking at the current dimensions we could add 3.5m-4m to the front. The approx width if the house is 3.7m. On reading the posts here there are mentions of cost/m2 what does this include? If it's just to build the shell - no decoration/electrical work/plumbing etc we are looking to keep this to £20k if it's at all possible?!??!

Thanks

Innys

nic1304 wrote: »

We live in a 2 bedroom end of terrece house with a reasonable sized front garden in essex. We have thought about doing a 2 storey front extension making it 3 bedrooms & adding a downstairs toilet. looking at the current dimensions we could add 3.5m-4m to the front. The approx width if the house is 3.7m. On reading the posts here there are mentions of cost/m2 what does this include? If it's just to build the shell - no decoration/electrical work/plumbing etc we are looking to keep this to £20k if it's at all possible?!??!

Thanks

I think the £1,000/m2 includes electrical and plumbing, but not decorating.

Based on the magic £1,000/m2, you'll be struggling. The sq meterage of your extension is around 13, per floor. So 26sqm for two floors, blowing your £20k budget.

I doubt labour costs in Essex would be much cheaper than anywhere else in the South East either.

nic1304

Innys wrote: »

I think the £1,000/m2 includes electrical and plumbing, but not decorating.

Based on the magic £1,000/m2, you'll be struggling. The sq meterage of your extension is around 13, per floor. So 26sqm for two floors, blowing your £20k budget.

I doubt labour costs in Essex would be much cheaper than anywhere else in the South East either.

Something else that has been brought to our attention is that you are not allowed to extend to the front of your house. Is this correct? We are not on a highway so would not interfere with public access & we would be in our own front garden! Could someone advise?

Canucklehead

nic1304 wrote: »

Something else that has been brought to our attention is that you are not allowed to extend to the front of your house. Is this correct? We are not on a highway so would not interfere with public access & we would be in our own front garden! Could someone advise?

Hi: see here.

HTH

Canucklehead

chrubble

I take it from the Planning Portal that if an extension to a semi-detached house is 3 metres or less deep and doesn't cover more than 50% of the existing land of the house (at single storey or 2-storey, as long as it is below the existing highest ridge tiles) and built in materials consistent with the rest of the house, that it doesn't need planning permission. It appears that the width in relation to the back of the house is unrestricted (as long as it doesn't extend beyond the existing width). Is this correct?

Louise20

Hi

I am planning on buying a house that will need to be extended for our requirements. But before proceeding in buying I want to be sure the extension is within our budget.

Can anyone advise an approx (ball-part-figure) to have a 2 floor side extension pleasE? It would be going out over the exsisting garage width and up a floor. We plan to move the current staircase that runs through the middle of the house to go along the side of the new side extension.

I would appreciate yours answers and advise ASAP as I don't want to miss out on this house.

Many thanks in advance