September 24 – Michael’s Low Energy House and a Goodbye to Samsoe

Samsoe km cycled 80
Samsoe km by car 40
Carbon emissions – zero (it was an electric car, powered by wind and solar)

The building regulations in Denmark recognize four classes of house – a standard house, low energy class I, low energy class II and Passivhaus standard, although the last is not certified by Passivhaus. In some ways the Danish Passivhaus standard is stricter, being based on gross external floor area, instead of internal and requiring an air tightness test in both directions (sucking and blowing).
To gain planning permission for one of the plots outside Tranebjerg a house must be minimum low energy class I. Michael’s house is a class II (total energy use, so not just lights and services but electrical equipment use as well, of max 58 kWh/m2/year) and has an air tightness of 0.8 l/s/m2 (better than passivhaus which is 1) underfloor heating fed from the district heat main and triple glazing. His EPC is a B rating and also contains the predicted heating energy use, but he says that he uses half that. We talk about energy performance certificates and it seems they’re taken a little more seriously in Denmark – partly because the cost of energy is higher. They are having a woodstove installed. He says that they don’t really need it but that it ‘feels cosy’.
He also has external shading (drop down canopies) for the spring and autumn – the sun is so much lower in Denmark than Austria that the real Passivhaus construction means overheating from solar gain in these seasons, especially with the solar glass which admits heat but doesn’t release it. The energy academy building is naturally vented but they have to override the ventilation in the summer and force the high level windows open more than the CO2 sensors would allow to cool it down.
Michael tells me that Danish studies show a 6-9% increase in cost to achieve Passivhaus standard, easily recuperated in energy savings, but admits that because energy improvements are not usually visible estate agents don’t value the houses much higher. Being a thatcher and a carpenter means he can do most of the work himself so it costs him less but money aside it seems he would go to the trouble anyway. Michael is passionate about building energy (the last house he had was 100 years old and he got it to a B rating) and he’s fired up by the workshop in Copenhagen the day before. He admits that the farmers on the island are very economically minded when it comes to energy but laughs and nods when I say that I think that Jan is more of an idealist that he likes to admit.
I ask what the typical owners of the low energy houses are – thinking that they’ll mostly be younger couples but he says that he and his wife are one of only three. The rest are older retired folk but then this is the population pattern on Samsoe. He went to a school reunion recently – out of 60 pupils from his year he is one of four who still live on the island.
The next morning I cycle down to the Ferry port at Kolby Kas in the dark. I meet a woman there who is returning to live on the island after 40 years away. I congratulate her on reversing the trend but she’s only coming back because of her aging parents.
I get a brew and go on deck to photo the sunrise over the lighthouse and the offshore wind array – all spindly spinning blades in the fog. They’ve doing some great stuff here, and I’m pleased to have visited. What I like most is that they measure everything – data is on line for the woodchip plants and wind arrays – and they make the knowledge available. In the energy academy they have a very ornate certificate signed by them and the mayor of a town in Korea promising to ‘exchange significant knowledge in the development of renewable energies wind and solar etc.’ It makes me smile – they do that anyway, to anyone who wants to listen, without having to sign something to agree to it.
But they’re not the most gregarious bunch and it’s not the most lively of places. In times past I’ve lived happily on a mountain top with only goats for company but maybe I have become something of a city chick these last couple of years. I’m excited at the prospect of wonderful wonderful Copenhagen and even more at having a buddy to share it with. Katface has come from Manchester and we’re meeting up for the weekend. She’s cycling from there to Roskilde even now to meet me at the Viking Museum and I can see the mainland looming out of the mist so it’s time to gather my things to disembark.