Summer is here!

The garden is booming now, and the hornbeam on the front porch is nearly full height now. I am really pleased with the refinished outdoor table. Ready for a barbecue!

A data upload

I haven't been keeping this up, so here are some summaries  for those who like charts:



 This show how stable the house is temperature-wise. Since we have central heating, the house is always comfortable, even if the temperatures look low to some people. My thermometers are not calibrated, so they may be slightly off. Note that during the warm weather in July, the house never went over 28C (82F).

Energy usage

You can see where we came from and how the PV gives us negative electricity consumption in summer.We have reduced our gas usage by 71% on rolling annual basis as of this month. We should get that lower, particularly if we put in a solar hot water collector. In the summer the heating is off (and through to October) so the gas consumption is hot water and cooking.

Now we have lights

We finally got our electrician back to install the remaining outdoor lights and sign of his installation for building regs. We should be legal soon. Thanks to Tony Taylor for doing some high-tech lighting models for the sunroom. It has all worked out brilliantly (so to speak).

The spotlights in the sunroom

Spring is coming, I'm sure

But it still feels like winter - we were working this weeking with a high of 4C (39F) and a sharp east wind. But I got my early birthday present installed - stainless steel rigging to train two hornbeams on the front door portico. Karen and I both worked on clearing the remaining asphalt from the planting beds - we just need some more topsoil and the trees can go in. In fact we are lucky that it's still winter - our planting season has been extended. Karen put the broad beans in anyway.

It has been relentless grey, but I went out to take a photo of the south side, and the sun obligingly came out.

Winter update

 I know some people still visit this blog, but we have been enjoying the house and getting out and about rather than doing jobs. But things are still happening. The sunroom glazing was installed in December by James Brewer and his mate- it really works! I love sitting out there when the sun is shining and basking.

We are also getting energy results that better reflect the design intent. One day I will update the Passivhaus Planning Package to see what that predicts. Meanwhile, we our annual gas usage is 57 kWh/m2a, compared with 171.5 kWh/m2a before we started, a reduction of 67%. (That high bar on the left was December 2011, when we had done most of the work, but not finished the insulation or airtightness. There is more air sealing to do!)

My own goal was to reduce by 80% - we could do better if we had a solar hot water collector installed. That may come when the Renewable Heating tariff is introduced and we actually shell out for the collector. The red line represents 120kWh/m2a, another Passivhaus target. We are doing well in that regard.

Airtightness update 1

Section showing cold air in the cavity

We have an internal cavity wall, due the house having two bedrooms added at the back. I failed to have it filled when we were bashing the house around, but it showed up as the source of a major air leak in our airtightness test. So today we had the cavity filled with polystyrene beads. The sections shows how cold air can infiltrate the house - even without air movement there could be convected heat loss, so we hope this will make a significant difference.(the cavity does connect top to bottom, but this section is through a door)

The boys wer pretty tidy

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.