Help on house extension

NickD71

Hello

We are planning a relatively basic 4x9 metre single storey extension at the back of our house in Surrey. Planning permission is not an issue. I have also got three quotes who are all saying it will cost around £1k per square metre.

I have a couple of questions. I presume that since all the quotes are similar 1k/m2 is a fair price, but would like to verify if anyone can confirm that.

Secondly, well, I also don't really know where to go from here. I spoke to an architect who quoted me quite a lot of money to draw up plans and a horrendous amount to supervise the building works. Do I need an architect to do this or are there other professions who can do the same but cheaper? Are plans even necessary?? As I mentioned above this is a simple rectangular extension, nothing fancy.

Help much appreciated am a bit stuck!!

muskoka

I prefer to have plans drawn up - only in that builders cant deviate away from plans if theyre in black & white. I believe the pricing your getting is about right though, in fact I'd go so far as that pricing seems competetive. Other bonus of using architect is they can work to your budget & recommend builders too.

My architect's plans cost me £450 for 2.4m x 3m (approx) extension with a vaulted ceiling. Plans also meant I could maximise light allowed in extension (i.e. only allowed to increase natural light by 25% unless you incorporate theremal calculations). Also architect if needed will get structural calculations if you need them. I just think architects fees are money well spent (in my case anyway). Architect also offered me ideas, etc to help make my extension just a little bit different. Each to their own though.

I'm no expert- just a girlee whose just had an extension built.

shirlgirl2004

I would have thought you'd need plans for building regs. You don't have to have them as you could do it on notice instead of an application but I don't think that's recommended for a larger project such as an extension.. Without indepth plans you can't be certain that the builders will be quoting for them same thing. Plans showing how the building is constructed will means there is now doubt about how it will be built.

iamcornholio

Have you really had fixed quotes for £1k /m2 or were they estimates along the lines of "Oh, it will be roughly about "x" amount"?

Such m2 rates can quickly double with an inconveniently placed drain, poor ground or deeper foundations

Your builders need to give a fixed quoted based on a properly designed and specified set of plans, not just a m2 figure design to reel you in.

Anyone competent can do the drawings, and you don't need them to supervise the work

You can have this built without plans (Building Notice route), but you rely on experienced competent builders to do the work correctly based on their own knowledge - its a risk for you and also a risk for the builders ..... which they may not want to take on

NickD71

Thanks very much for your help, think I will get the plans drawn up after all.

SailorSam

Is there anything here that can give you an idea of costs.

Building- Cost and Estimates including House Building, Roofing, Garages and Conservatories