Situation improved
On close examination I could see that the rubber seal did not clear the shootbolt keep and was dislodged whenever the door was closed. I disassembled the shootbolt keep and found that the spacers used were too large ~6mm height. I removed and replaced the spacers and the door closed without distorting the rubber seal. This was really not for me to resolve and I wonder how many other doors are out there with the same issue?
I have to say that is my experience too. The windows I fitted myself were fine when we had the pre-upgrade air pressure test the two doors that were put in professionally were awful!
Door steps bridging damp courses are a problem too - I have three and they have all caused thermal bridge and moisture problems.
In the kitchen , the tiles by both doors are cracked where moisture has seeped in.
The steps need to come down a brick level basically.
Just inside the front door the hallway has signs of moisture ingress on the wooden floor and the wall.
I’d never have linked these were it not for an excellent damp surveyor we had to the house when we bought it.
