Depends who they complained too. Its it was to you, thats fine, if it was to the council, that, effectively, stops the clock. Though if they take no action, thats debateable.
If you insulate externally, the floor will still be connected to the ground, and the arches connected to that. So the arches will still be a cold bridge regardless. Unless you clad them.
I cant speak for the small print on your warranty, but you have no comeback on building control. They are protected by law from any responsibility. (which is why i always question what actual use the whole process is?)
The advice to persue the builder would seem correct. Trading standard wont be much use as houses are not covered by the normal consumer protections.
Thats interesting. Does that mean you are effectively exporting at the same cost as purchase.
I ruled out exporting, partly because i have a spinny wheel meter.
Unless you specifically asked for something breathable, its almost certain its conventional render/pebbledash.
But if you dont have any damp, thats good news. Its not a given you would have.
The leaving a small cavity approach can work, but it will need ventilating, and needs to be done such that the cold fresh air doesnt leak into the house elsewhere.
A damp house will always feel cold
Damp walls are a thermal disaster.
Fix the damp (as suggested above) then worry about the heating.
Sadly, its a minefield.
I dont have any answers, but i had the same issue with DVLA and their ombudsmen.
They point blank refused to refer me, despite having reached that point in the process, whilst at the same time, point blank refused to deal with the issue.
Not sure what the point of an Ombudsmen is if you are reliant on the fcompany that has failed to refer you.