This is not an exhaustive or a complete subject. It is likely to change over time, with edits, additions and deletions, and is simply a collection of my thoughts based on many years of experience. You should follow your instincts, and you must always seek your own professional advice.
Condensation is potentially a serious defect that can occur in any building, of any age. Modern buildings can be impacted just as much as older buildings. It is simply a factor of science and when the conditions are there, condensation will occur.
There is moisture all around us, all the time, every day and night. We can see condensation occurring on walls and windows when the surface temperature reaches the dew point.
As the air temperature reduces, the risks of condensation occurring increase. Maintaining warmer air, warmer surfaces and having good ventilation can help to avoid these problems. Good natural ventilation means an exchange of air between inside and outside. This is especially important in bathrooms and kitchens.
We are all being encouraged to insulate our homes to conserve energy. That is only one part of a very complex conversation. As we insulate, we must also ventilate. The race to retrofit our older homes is already leading to severe condensation problems being seen when internal wall insulation has been used and has been poorly designed and installed. Worse-still, many of these projects have no design at all.
It is a very complex science and there is plenty of easy-to-read guides now available online to educate the trades, the professions and, very importantly, the homeowner.
This straight-forward and well illustrated video by Rich Alsbury provides a good example of how condensation occurs and how to look out for it..:
Disclaimer: Anything posted in this Blog is for general information only and it is not in any way intended to provide any advice, legal or otherwise, on any general or specific matter that you can rely on. You should always seek your own legal and surveying advice.