Recent advances in building construction have called for airtight buildings to meet stringent requirement for 5 and 6 Star ratings.
This kind of thinking is good in theory, however, in practical terms is totally irrelevant.
The problem for condensation is the over insulation of today’s homes to comply with these over the top requirements. These requirements for the over insulation of today’s homes have been concocted by office jockeys and the recipients of this windfall the insulation companies.
Don’t get me wrong, I believe the necessity for insulation, however the more insulation the more need for natural ventilation.
Unlike the office jockeys with their text books and their coffee meetings I have been a roofer for over 50 years and have seen all that can happen with condensation within roofspaces.
Sure, the need for insulation to keep us warmer in winter and cooler in summer goes without saying, however without effective air flow to remove the heated air trapped between the ceiling insulation and the blanket foil under the corrugated colorbond metal roofing, will loose the water vapour and you could have a big condensation problem.
You can see many blogs on this site regarding condensation.
“Condensation Energy Efficiencies Unwanted Companion”
In a well-ventilated home condensation will swiftly be eliminated.