Current building costs - rough cost per M2?

[Swampy]

Hi, 

 

We’re going to build an extension on a house we’re buying and have a set of plans, but we’re finding it very difficult to get a rough estimate of the cost - to make sure we can actually afford the work, before we complete on the property. 
we have plans, because a neighbour has done the exact work that we want to do. We will of course get our own set of plans, when/if we complete. 
 

I appreciate that build prices have increased a lot in the last couple of years, so can anyone provide a guide to cost per square meter? 
I’ve seen these guide values before, but what with prices going through the roof, I wondered if anyone has seen any updated figures? 

It’s going to be a 2 story extension to the side and half of the back of the property, plus we want to do a loft conversion (in case that’s relevant). 
 

Thanks. 
 

[Russell griffiths]

Need pictures and rough plans and area of country. 

[Swampy]

12 hours ago, Russell griffiths said:

Need pictures and rough plans and area of country. 

We’re in Berkshire, but I don’t have electronic copies of the plans that I can upload. 
 

[Andehh]

Take a photo from your phone & upload them? Could be anywhere from £3000 - 3500 + VAT is my wild stab in the dark based on too little info.

 

[MJNewton]

I would think your neighbours costs are going to give a much better indication than a generic per sqm cost, which hasn't really ever meant all that much given the variability relating to content and final finish, particularly for an extension. 

Edited June 15 by MJNewton

[Bob77]

For a 40 square metre single-storey extension in Hampshire, along with a couple of internal structural walls being taken down, I have had quotes between 72k and 120k. I went with the lower end so I'll let you know whether that was a mistake!