how to price for building extensions?

Question

i want to start my own building company and a formula on pricing extensions would be helpfull

Answer 1

when i was doing it years ago i would get the total volume and then x it by the price per cubit metre, i used this as a rough guide to give a reasonable estimate,hope this is helpful to you
you can buy a book that will give you the costings of most jobs

by alec

ps you have to know the prices of the materials to know what to find the price to x by

Answer 2

I suppose the logical thing to do would be to start with a price for the smallest, say 8x6 ft @ £12,000 and increase this by £1,500 per sq. additional yard. You would have to play around with these figures to arrive at the price band you want.
We have just had a 10ft x 12ft extension and it was £13,000.
In London it would probably be £26,000.