PVs are working

We installed the photovoltaic panels about a month ago, so we have the first results. Our electricity from the grid went down from 278 units to 98, and we generated 179 units. Therefore we generated more than we used from the grid, and our electric bill for the month will be about -£25. This was not a main element of the design, but it made sense for us to take advantage of the feed-in tariff. We will be more focussed on our electricity use as well. Photos of the PV installation tomorrow. The gas usage was high in January because we hadn't finished insulating and commissioning the MVHR - and it was cold! Next winter should be much better; we have used about 42% less gas for the first six months than we did before, but intend to get closer to 80% less when we sort out the airtightness.

No, we're not finished

We conducted the first airtightness test last Monday, and the results were a little disappointing. At least I know where to apply effort to improve things. This is one criteria that will probably ensure that we can't get Passivhaus EnerPHit certification. Have to see what the remedial work gives us. For you cognocenti (and the others), the original house was a typical 1950's job, with and airtightness around 16 ach (air changes per hour) or more. Current regulations for newbuild is 10m3/m2, close to 10ach. We achieved 4.5 ach, but the  target is 1 ach. So lots to do. The internal cavity wall is one culprit that will be hard to correct.

Door fan in place, with monitoring equipment connected

MVHR pipes into leaky duct - needs proper sealing at the first floor ceiling.

MVHR filters bagged and taped to avoid air leaking out or in