would it be much cheaper to have a unfinished extension so we can do our own bits. just have the basics done eg walls roof etc

Hi Depending on your level of skill and the finish that you requier you may save 10% on the build cost. The Natinol average build cost per Sq m is £1,300-1,800 this will give you a totally finished build that you just move your bits into. regards Ashley

What area are you in? We cover the northwest and price extensions per cubic foot. An example of a 5.5m x 5.5m extension, single storey would be (fully finished) £23,000 or (walls and roof, including windows and doors) £15,000. We are available to price this up for you and we offer free written quotes and carry a full portfolio with references from previous clients. Hope this helps All the Best, Dave Woolhouse

Hi If you are an electrician,plumber,plasterer,joiner etc you will still have to pay for materials and you will have to pay all these various tradesmen and organise the work your self unless you have friends then you will still have to pay them something unless you give it a go your self in which case " in my experience" it may well cost you more, for the amount you save you may as well negotiate the price of the work down and let your builder complete the work and end up with a well done job and in a much quicker time.