Two story extension cost

laughsatcats

Does anyone know ballpark figure for cost of a two story extension on to a semi? It would be approx 17 ft deep and 10 ft wide with garage\study underneath and bedroom on top in Swindon area including plastering and skirting etc.

I may also consider ground floor extension of two rooms ie study and kitchen/diner about 30 ft by 10 ft total.

They would be rendered and built with blocks.

So any ideas for either as won't be doing both.

Thanks.

KennyH1

If you work on £1250 / m2 then you wont be too far off.

Usually for domestic properties you can work on £1000 but as you are doing some 1st floor works then a slightly higher value will come in to play.

This will get you a fully finished extension, tiled roof, plastered, electric etc etc.

andrewf75

yeah anywhere between £1000 and £1500. From personal experience it always costs more than you think!

and use metres not feet, thats what builders work in and any cost estimate will be done by

Clive_Woody

Be warned the average costs may not be applicable to you.

As I type we have builders busy at work on our single story 4 x 5m extension. One of the biggest individual costs was the foundations as we had to go 2m down as we have big oak trees and high shrinkage clay soil so needed very solid foundations to get building regs approval. A lot of our money has gone underground, only now if the brickwork going up.

Don't want to panic you but you need to be prepared for a few surprises and extra costs. Also get lots of quotes, ours varied by over £10k.

andrewf75

Yep I suspect the so called average costs of £1000 odd per sqm are in fact better described as minimum costs where everything is completely straightforward and the extension is very basic.