if hes any good he will sort it out with you before they start
both myself and a girl at work are both having work done at the same time
I used a builder who had been in the trade 40 years, she used a much younger contractor
my builder was a lot more relaxed about the money..he didnt ask for a penny until about 2 weeks in..then he wanted 25%
he then asked for another 25% when actual walls built, roof finished, doors and windows fitted
he then got the remainder when plastering was complete, floor down, heating and electrics finished ( as well as other sundries, I asked for a new rear boundary wall, rear gates, some additional exterior lighting after they started and he just factored it into the end payment..but basically when all works complete)
the girl at work getting hers built , their builder asked for 50% as soon as they had broken ground for the foundations
I can only assume my much older and longer established builder had much better lines of credit with builders merchants and suppliers...he is also very busy with other projects happening at the same time as well as general maintenance lads so probably has cash flow all of the time..as it happens there has been no snagging problems at all and I have asked him back to fit some full height bespoke shelving as he is a joiner by trade and he did some lovely rear gates for me