Thanks for this , i did get the deposit paid via amex and fee free , not sure if they will go the whole build though , cheersI have done this a couple of times.
You must convince the builder to accept Amex directly from you.
Even if builder does not have this facility, they should organise it just for you as you are paying them huge sums often with large margins. You will need to pay the Amex fee incurred by builder but this should only be circa 1.4%.