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, 2022 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!