We opened the house up for visitors last weekend as part of International passivhaus open days. It was nice to see friends as well enthusiats from further afield, so thanks everyone who made the effort despite the damp weather conditions – hope mince pies & mulled wine helped. I think it was quite interesting for the visitors to see our house under construction (warts and all) rather than a finished article. We received very positive comments, and some potential builders are now considering going down the ‘passivhaus’ route, or using more sustainable materials in construction.
This week we’ve had the whole roof insulated with recycled cellulose. The roof structure consists of 400mm deep timber I-joists, so the choice of insulation was quite critical in terms of achieving the right thermal performance and filling the gaps fully between individual joists. I am a fan of recycled cellulose, as it’s a sustainable product (imagine all those tabloids finally put to a good use!), it can moderate moisture movement, it fills every nook and cranny when installed and it greatly helps with acoustics – especially in our case as we’re using tin roof as a finish. Cellulose was pumped into individual bays between I-joists through small holes in the airtightness membrane. These were meticulously taped up after the installation to maintain proper function of airtightness layer. Timber battens to underside of membrane will form an independent service zone, so any installations will not compromise the airtightness.
We are expecting the first blower door test next week – this will give us an early indication of where we are with overall airtightness performance. Anyone wants to place a bet?