Dan do you ever talk about retro fitting old houses at your monthly talks.
It would wonderful to learn what can be done to existing (my home is 1880’s) buildings to improve their performance.
Not exactly the same, but my city is retrofitting a lot of Soviet-era apartment blocks to bring them up to modern standards. They are made out of concrete with no insulation and were built when (natural) gas was basically free.
The bulk of the work is wrapping the building in 25cm of rigid foam exterior insulation, replacing windows and making sure that they are fairly air tight. They aren't adding mechanical ventilation, as installation would cause too much disruption to residents who are living there. Heating systems are being upgraded to newer units if they are old and inefficient (still powered by gas or district heating, no heat pumps).
The main issue with older buildings is often you want to maintain the 'character' so wrapping the building in external insulation and replacing the facade isn't always an option. However if you have a building made of masonry this is the best way to insulate it, as the masonry then acts as a thermal mass to keep temperatures inside more stable (in both hot and cold weather). These apartment blocks were ugly concrete that nobody wants to ever see again though, so it's not an issue here :-)
>The bulk of the work is wrapping the building in 25cm of rigid foam exterior insulation, replacing windows and making sure that they are fairly air tight. They aren't adding mechanical ventilation, as installation would cause too much disruption to residents who are living there.
Hmmm, like the worst possible idea (air tight + not adequate ventilation), the early (10-15 years ago) "Class A" or "Class B" new buldings made here without appropriate ventilation have given lots of problems (humidity/mould).
The only possible remedy being daily manual ventilation, i.e. open windows for 10/15 minutes every single day (but many people won't or cannot do it).
