So, I was out at #OpenHouseLondon this weekend. It turned out to be a quick case study about all the “rebirth of industrial policy” stuff set out in Duncan Weldon’s piece in Renewal.
The building in question is the Mildmay Community Centre in Dalston. It’s a Passivhaus, designed to a standard developed in Germany to use absolutely minimal amounts of energy for heating and cooling. More interestingly, it’s a Passivhaus retrofit – there was a building there all right, a former tram network power station, that was first reused as a community centre and then refurbished.
This is interesting because everyone knows it’s possible to build this way, but the UK has a hell of a lot of old terraces that no-one’s knocking down any time soon. If we want to get the CO2 emissions from buildings down, and the energy bills, and the import bills, we really need to be able to improve the stock of old buildings as they stand.
The key elements are a ton of insulation, a ventilation system that concentrates the air flow through a very high efficiency heat exchanger, and a lot of attention to quality control during the construction. This particular one has managed to cool down to 19.75 degrees C overnight on its coldest day, which impresses me as I used to live in a flat that wouldn’t get to 18 degrees C on cold days if you ran the heating flat out continuously. While I was there, it was hilariously cosy.
But here’s the point. The whole project is imported from Germany. I couldn’t find a component that wasn’t. It might have been shipped over complete. Even the Passivhaus Foundation’s planning software tool is proprietary, German, and quite costly even if it’s an Excel spreadsheet. (Surely we need OpenPassivhaus.) Not to be bigoted, but this means that fixing the buildings will be a drag on the rest of the economy.
I asked the architect (Justin Bere) about this, and learned something interesting. There are 2 companies in Germany that make the window frames. They get timber from timber merchants who have growers in south Germany and the Czech Republic signed up on long contracts. This is important, because the precise specification of the timber is important. A big problem is “getting the trees right”. The timber gets prepared, cut to size by automated CNC machines, and then gets assembled by master joiners, which is interesting in itself. Anyway, remember the Mosquito, partly built by the folk who later brought you glorious pseudo-Scandinavian Ercol furniture? Sure you do!
There are efforts to build up a supply chain in the UK – apparently there’s a housing association in Yorkshire that’s interested in producing some of the components. You can see how this might fall into place – housing, energy, supply-network development.
For a twist, though, what about labour? The contractors on Mildmay apparently found this tough. Passivhaus requires a great deal of attention to quality. Sealing tape has to be exposed on precisely half its width before application. They assigned a trainee as the passivhaus guy, possibly a tough job. This will have a bearing on life on the site. That wants thinking about.
I recently had a victorian house renovated to near passivhaus standards. The only German kit used was the heat recovery ventilation system. One of the key innovations – slim double glazing units filled with xenon that can be retrofitted to old windows – has been pioneered byUK companies. The problem is that the house has to be practically gutted to retrofit wall insulation and ducting for heat recovery ventilation. Anyone doing this has to be prepared to move out for a few months and use a lot of labour.
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