Two Storey Extension Cost

System

It's very normal to now have a cost savings exercise to figure out how much of the extension you can get for the money, look at the detailing etc and see where and how you can save some money, usually you do it with your architect and builder to get to a price you are happy with.
I regularly have a discussion with clients where they simply don't believe or want to hope that the prices aren't what we tell them, so include absolutely everything they want in the tender, then when it comes in overbudget we reduce it until the figure is comfortable

teneighty

Building price per square metre is a perfectly acceptable method of calculating a budget estimate.

The trouble is it is only intended to give a rough budget price so is a very broad brush approach. The rates range from £1000 to £2000 per square metre with lots of scope for adjustment and interpretation to take into account scope of work, quality of finish, location, access etc. and obviously does not include associated works to the existing house which should be calculated separately.

Breaking down your quoted figure gives £1666.66 per square metre which is within the range given but without knowing the details of the job we have no idea if it is reasonable. I have to say £1000 seems rather optimistic for an extension for anything other than a very basic build in the cheaper parts of the country.

loofer

tafer2uk wrote: »

My wife and I were hoping to build a small two storey extension to the rear of our property, with a small side extension. The total floor area for both comes to 63m2. The architect we employed to design the extension stated that he expected the cost to be approximately £1000m2 finished to a basic specification including kitchen, upvc double glazing, and bathroom furniture in two en-suites.

Looking around various websites and using their building tool calculators this seems a little optimistic but should be looking closer to £70k.

http://householdquotes.co.uk/cost-of-extension/

https://www.homebuilding.co.uk/


In the search for a builder which has been a struggle the two that have got back to us have both come in at £105k including VAT but excluding kitchen and bathroom fitting which we think will take the total cost closer to £115k.

I appreciate the quality of the final finish can have a big impact on the price but for the basic build what are peoples thoughts on the price quoted? I live in Yorkshire if that helps. Thanks for any input anyone has as we've never done anything like this before and so are pretty much clueless.

Hi, I'm n the very early stages of planning an extension. Did you get round to the build or even further quotes?

Also, if you get planning permission but then after speaking to builders they suggest changes that could make it cheaper, wouldn't even the smallest deviation from agreed plan involve another/amended application with council and possibly building control approval?

Doozergirl

Of course it depends on what changes are made. If it means spending a relatively small amount to ensure that your build is actually affordable, then it's economy.

The client I work for has a '4 sets of eyes' approach before a planning application goes in. One of those sets are mine, the building project manager. He picks his builder primarily on quality and reliability, and trusts me to spend his money wisely to a budget set before that planning application goes in.

The OP's quotes of £1350 per metre plus VAT seem perfectly reasonable to me.