We're just coming to the end of our extension project. Generally we've been really happy with the Builder. Our original quote included fitting of new kitchen flooring. At the time I said it would be a wood laminate product but two months ago at the start of the project I changed my mind to vinyl tiles (karndean type). I checked with the Builder and the fitter that the product was okay and showed them a sample before ordering. I had it delivered on the day they chose. Once they started fitting it they complained it was a pain because the tiles were half the size of a laminate plank and it was too lightweight and needed to go under the kitchen not around the units as they'd originally wanted to do. They also found it hard to fit so it took longer. Now the Builder is saying we have to pay £250 extra towards the cost of the fitting. The joiners (who also did the kitchen and roof) are saying it took longer than they had planned for. They've also left the Builder needing to hire another joiner to do the skirting and doors as they now don't have time. Would I be unreasonable to say no to paying the extra?