we paid our builder for our new windows but the joiner he uses will not make the windows as he says the builder has not paid him. What can we do?

if you still owe money to the builder for other work hes doing use that to pay for the windows and deduct it off ur builders final bill dont pay any more money to the builder untill hes up to date with the work

The contract would be with the builder, the onus is on him to arrange for the windows to be made, I can understand the joiner not wanting to make them if he hasnt been paid. He either has to pay his joiner or get another joiner. Dont pay him any more money until its sorted.