Persimmon reacted to our complaints about the wet electrics specifically by upgrading our garage electrics with 'weather proof' covers and conduit - we never accepted this as any solution, but went ahead and let them complete the works.
They are ignoring the point that it is still possible for me to stand in the rainwater puddle on the floor of the garage and touch live electrics - not something that anyone can claim is 'in spec'.

hmy: ZAP!!!

hmy:
Through our independents (NewBuild) we have access to the NHBC regs, and it is the fact that the garage wall fails the specs for water penetration that we will be showing to NHBC on 4 Mar in our meeting.
We have everything catalogued, with photographs, etc, to demonstrate the problem. We will also have a sprinkler set up to demonstrate to the inspector how fast the water soaks through and starts running down the inside - QED really.
We want Persimmon to provide and apply this weatherproof coating under NHBC regs as if it doesn't fix the problem, they'll be back.