My builder has started extention and now says he has under quoted me

In his quote he will have a 5 percent uplift for wastage on materials this is normal and up to 30 percent uplift on the price of the materials he has ordred. On that basis he could be as much £18200.00 in pocket. Sorry for your bad experiance we are not all like that.

How has he changed the style of the roof and what was the reason given? I normally put a 2.5% contingency on a new build, 5% for a renovation, this will 99 time out of a hundred, cover any little extra's the client will ask for not included, or variances from the original plan, if I make a mistake then that's my problem, not clients. I find it hard to believe somebody is 30% out. 35K for the shell is 70% of the budget of the job, at least 20% too much, I'd say 25% too much personally. Have you had any major problems? Foundations? Drainage? You may have to get in touch with trading standards pretty quickly if there's no contract of works, all in all its a bad situation that needs to be sorted ASAP. As Yorkshire says, we're not all like that, I always encourage my prospective clients to go see and talk to past clients, and look at the resulting projects, ask if there were any problems etc. Its such a simple thing to do yet I'm amazed why people don't? Best of luck and come back on the site if your still struggling, above all else, don't let him bully you into giving away your hard earned money, always make sure somebody else is with you when your negotiating with him. Hope this helps

Sorry to hear of your problems, there are many good contractors on here, none of us like correcting work tho. All I can say is every one on this site has public liability! And insurance just to be on here! If it didn't meet regs I would look to legal advise.

Hmmmm.... Law of contract (tort)......basics 1. OFFER (contractor offers to do works at a specific cost 2. Consideration - accept / negotiate / decline. 3. ACCEPTANCE(customer accepts quote - quote being different from estimate) I'm sorry but a 15k oversight is ridiculous unless you have changed the specification, thus a new contract takes force.... During the consideration phase I am open to negotiation. At this stage I know what my proffit and material costs are..... On a a basic 5k job I can tie this down to £100.....15k is ridonculous!

15k underquoted = his problem not yours.