cost of single storey extension

[DIYedboy]

I am thinking of extending the rear of my 1930's semi detached home. The extension will be ground floor only, 10 feet deep and 20 feet wide with a flat roof. I will pay someone to dig out and fill the trenches, plaster and do the flat roof, but I will do the rest myself. How much will the basic structure cost? I'm guessing £20K???

 

[noseall]

You would get a basic shell built, of that size, (no windows etc) for aboot £12k.

It's difficult to understand what you want pricing?

 

[DIYedboy]

Thanks Noseall, my reason for asking was to see whether I could get my money back on the increase in value on the house and the answer is yes if I do the work and no if I paid to have it all done

 

[boycey9]

I am building a 3x5m rear extension on a similar property, Its has a pitched roof with three rooflites, So far I have the building up and watertight and the insulation finished in the roof and the floor and have knocked through. i used a digger with driver for the foundations and a mate to help with labour and complete blockwork. All in all paid about 10 days work.
Also had a guy in to do the roofing.
Still got rendering to do on outside.
To date Ive spent 11k, I hope to finish the entire project including a kitchen and appliances and all finishes at 20k and I am not far off this at present.

I am not a builder but an average DIY'er, Im sure it could have been done cheaper but sometimes If I dont know what to do or where to get things at the best price I may pay more than a builder would, Also have to consider time as spending time shopping means no building. Its not an easy job and although I enjoy it it can be very frustrating at times, If I had the money I would get someone in to finish it for me everytime.