We have been in our new build for 2 years.
Wiring I wish we had done different.
External lighting done with the wrong cable for PIR lights ( 2core used should have been 3core ? )
Only got rear external sockets , used a lot but should have had one at front as well, perhaps by EV charger.
Wiring for towel rail did not allow for timer.
Things I like.
2 consumer units only one supported by battery in event of outage, so heat pump and towel rails do not drain battery. Because of automatic gateway often do not realise we have a power cut.
5 amp lighting sockets for side lights in lounge , hall and kitchen family room, switched by door.
We put high level sockets for extra bathroom heat, been here 2 winters and not used them, but who knows when I’m 90 ( a bit too close for comfort)
Put small distribution box in Garage, so easy to take an extra feed to greenhouse or summer house etc.