I joined a throng of about 250 people gathered last night in central London to hear a 40 minute lecture by Wolfgang Feist, Mr Passivhaus. In the obscurantist world of energy efficient building design, Feist is the nearest thing you will get to a superstar and this was the first time he had spoken in public in the UK. He spoke in excellent English and held the stage with his presentation, although in truth, for those who already know about the Passivhaus movement, there wasn’t anything particularly new to be gleaned. In any event, he was preaching to the converted, although in the bar afterwards it was suggested to me that I wasn’t wholly on board. Oh dear, what is it with me?
A few snippets I did glean. Feist and his family actually live in the oft-photographed original Passivhaus terrace built in Darmstadt in 1991. This is where the story started. His average energy consumption for space heating in this house is just 9kWh/m2/a; the Passivhaus standard is 15kWh/m2/a. In fact he showed a fascinating slide showing that though 15kWh/m2/a is the hoped for energy consumption in a Passivhaus, the range of outcomes measured at 32 Passivhauses on an estate in Hanover was between 4kWh/m2/a and 25kWh/m2/a. “if people like to keep the internal room temepartures at 25°C, then the energy use is going to be high. But then it’s still going to be much lower than on conventional homes.” He showed that such a range of outcomes was fairly typical across any group of homes studied.
He also said he was proud of the fact that were now over 40 Passiv Schools in Germany: schools of course help to disseminate the principles of low energy design because they are used by so many people.
Finally, he invited everyone to the next PassivHaus annual conference in Frankfurt in April 17/18 next year.
The talk was put on by the AECB, who also used the spot to promote their CarbonLite standard which is closely based on PassivHaus principles. What wasn’t explained was why the AECB should be supporting a different standard. Perhaps it will all become clearer to me in time.