Moisture has to go somewhere even if you don't see it visibly condensing on windows.
Either it's being absorbed or you have something removing moisture from the system (venting, etc).
Either it's being absorbed or you have something removing moisture from the system (venting, etc).
With good building codes, you won't have condensation issues.
Alas, we are a very silly country.
Some insulating panels are also dreadful, but on the whole a semi-competent installer will do the thing right. The problem is, some aren't even that good - we're talking a minimum bar of an NVQ level 2, and that's if people don't decide to just.. go self employed and do it without training. No regulation at all, and there can't really be any until it is a licensed occupation.