Costs of extension

[NoTeaForMe]

I know this has been done a lot but...what is the figure you use to work out the cost per square metre for an extension? What if it’s 2 storey? Thanks.

Where are you based? I'd start at £2k per square m but it depends on different factors

I’m in Essex.

if you're going double storey its double the square footage.

Tbh, it depends on a few other factors as well.

What else is currently standing where the extension is going to be?

Ease of access for builders?

Level of finish in the interior

Type of roof

Whats the ground like

Structure of the extension. (Side, rear, wrap around)

In general, for a good size 3 bedroom semi, in South East:

A single 18m square storey side extension (consisting of 1 room and a bathroom) will cost between £30k to £40k total (inc bathroom fittings). Depending on the level of finish you desire.

I've heard £2000/sqm min for single story then add 50% for two.

I don't think that works at all @Midlifephoenix - I think the figure of £2k per sqm is for each storey. Certainly when we did a double storey extension we budgeted (and it worked out at) about £2k per sqm based on calculating the total sqm based on ground floor sqm PLUS first floor sqm.