Never again have a problem finding reliable builders that will help you build a good house. Either it be a loft conversions or just a simple single storey house extensions. It is very important to have a good builders in your arsenal.
Anything you can do to make sure builders are hired that can do a good job is recommended. Sure, you may get a good deal if you work with people with barely any experience, but then you're putting your investment at risk. Damages happen a lot more easily when you hire a builder without doing your research.