We endeavour to design and detail buildings with a high level of airtightness. Having an airtight house means that its thermal performance is much more efficient with the warm air being unable to escape through the building fabric. It’s still very important to consider the airtightness of a building even if it has been very well insulated; the warm air will inevitably find it’s way out and you’ll have to pump the building with more heat to keep the ambient temperature stable.
We’re reaching the end of a barn conversion build at the moment and it was recently pressure tested to assess the level of air changes, or in laymans terms, how much air is leaking out of the building. The level achieved was an incredible 0.9 air changes/hour@n50, which surpasses not only the Building Regs target of 10 air changes/hour but also the Passivhaus retrofit target of 1.0 air changes/hour@n50.
This is an amazing result for a leaky old stone barn and has been achieved through careful and considered technical airtightness detailing, with diligent workmanship and attention to detail on site.