Pete, no matter whether you use a major or a minor (but more so if a minor), make sure that the progress payment schedule reflects the percentages set out in the regulations (you are allowed to vary them, but I wouldn't agree unless a very non-standard project). Never have money with the builder that isn't for work tht has been fully completed. If you like most are relying on bank funding they are strict on this anyway, but contracts are often signed up between the builder and the customer without any advice, so keep an eye on that.

As mentioned earlier, there are some builders with real issues at the moment. I have quite a few small builder clients, and a couple (and one in particular) despite being apparently strong and having a good reputation is on a knife edge and could easily end up failing.