Reflections from members of the Green Building Store team who attended
Chris Herring, Director, Green Building Store
Thirteen years ago, I attended my first international Passivhaus conference. It was an exotic location in the Bregenz opera house right on the shore of the Bodensee in Austria (and in fact the stage is actually in the lake!). At Green Building Store we had been thinking about Passivhaus as the way forward to enable buildings to become truly energy efficient, and this thinking was running in parallel with work the AECB was also doing on advanced energy standards. So, the conference gave me and my friend (and future Technical Director of the Passivhaus Trust), Nick Grant, the chance to begin to get to grips with what Passivhaus was all about. There was only a handful of UK delegates at the conference, and in the final closing plenary the UK didn’t get a mention…we were literally not on the Passivhaus map. But the great thing was that we both came away convinced that Passivhaus gave a way forward to achieving buildings that were truly low energy and that really worked. We were inspired.
Jumping forward now, 13 years, the 2020 UK Passivhaus Conference just demonstrated how far we have come. We have a huge array of buildings on the ground, we have world class technical expertise and a growing workforce – from design through to construction – able to comfortably work with the exacting Passivhaus standard. We also have the Passivhaus Trust, which I am very proud to be able to say that I helped found, which was celebrating its tenth anniversary. Ten years ago, the UK had achieved a few pioneering Passivhaus projects, like our very own Denby Dale Passivhaus. Just contrasting that with the level of technical expertise demonstrated and the scale of what is happening now was quite extraordinary, from large scale housing developments in Glasgow, York and Ealing to name just a few to the ambition of some of the schools or the extraordinary St Sidwells leisure complex in Exeter. We may not yet have achieved the level of ambition of the Bahnstadt in Heidelberg, or in fact the complete city development in Gaobeidian in China, but never the less from almost a standing start a little over 10 years ago it is quite an achievement.
So, there was certainly some reason for celebration at the conference and that is what we intended with the final anniversary session. Looking back is important, just to take stock and to recognise what has been achieved by all of us involved with Passivhaus. But in the end, it is looking forward that is much more important, and what we asked our final discussion panel and international presenters to focus on. We may not know what will happen with Passivhaus over the next 10 years. But it is clear to anyone who understands what the Standard offers that learning the Passivhaus lessons needs to be at the core of our construction industry and the lessons need to be learnt urgently. Climate change is already happening, and if we are to mitigate its very worst impacts the next decade is critical. It may well be the most pivotal decade in human history. We know that demand reduction is an essential element of any solution – every piece of modelling which has been done demonstrates this. With Passivhaus, we have demonstrated that we have the most effective demand reduction solution for the construction industry. So, the challenge for all of us now is to make the difference and to get that message out there in any way we can.
Luke Gilman, Manager, Windows Department, Green Building Store
It was great to listen to Barbara Lantschner’s talk about John Gilbert Architects’ Niddrie Road EnerPHit project. We have worked with John Gilbert architects on previous projects and they have specified our ULTRA insulated frame inward opening windows for Niddrie road. Most Passivhaus or Enerphit projects we supply to use our ULTRA solid frame range, but having the option to insulate the frame to improve the Uf value has proven vital for this project.
It was good of them to share their experiences and the difficulties of designing to EnerPHit standards on an existing tenement building, and the challenges they have faced given the location, orientation and form factor. We understand the importance to improve the current housing stock around the country and we hope that this project is a success and can lead the way for other projects of a similar nature.
Emma Platt, Aftersales Manager, Windows Department
Being the 10th anniversary of the Passivhaus Trust, it felt very apt to look towards the future. Harry Paticas’ talk about the Retrofit Action for Tomorrow work he is doing with St Winifreds Primary School was very uplifting. Children love to understand the world and to be actively involved in decisions which affect them, so being involved in redesigning their school buildings to make them more efficient and also be a healthier place to learn is a perfect idea. The children quickly embraced the idea and will take that knowledge with them for the rest of their lives, hopefully having a positive impact on the way they live and also their interactions with their own homes. Knowing this isn’t a one off and that they already have more schools lined up is fantastic. Harry might even have inspired some future Passivhaus designers! Watch the Retrofit Action for Tomorrow film
Richard Jarnot, MVHR Designer, Green Building Store
It was very interesting to hear Patrick Brown from City of Edinburgh Council talk about the push towards Passivhaus schools, which is being spearheaded by Edinburgh council, including their drive to achieve operational carbon net zero by 2030, 10 years sooner than Scotland’s 2040 target. The importance of the Passivhaus approach in schools is key and the benefits of MVHR to indoor air quality, such as increased concentration, reduced headaches and optimal humidity, will be huge on students and teachers alike.
Camilla Govan, Business Development Manager, Green Building Store
Overheating is an issue that many people seem cavalier about, evidenced by the fashion for wide floor-to-ceiling glazed units. Modelling in Passivhaus is extremely useful for predicting overheating, but the official allowances for 10% overheating and the option of mitigation measures concern me. In this context, I was so glad to hear John Palmer explain how the Passivhaus Trust is developing a new tool for stress testing summer overheating. It was useful to hear reference to the degree of cooling expected overnight being about 30C and an evaluation of the impact of thermal mass in this context. It was also interesting that the risk of overheating does not seem to be made worse by Passivhaus standard insulation. Building design, orientation and external shading are key factors. Other interesting overheating references from presenters included Jae Cotterell and Anna Carton of Passivhaus Homes talking about their experience of retrofitting in London and post-occupancy review highlighting various problems not completely predicted by their PHPP, including the impact of very high levels of occupancy, I think double the PHPP predicted maximum numbers. And finally, there was the significant reduction in both internal heat gains and primary energy use from the point-of-use hot water in a health centre situation, covered in Peter Ranken’s presentation. A big thank you to all the presenters and the Passivhaus Trust for an excellent conference.
Chayley Collis, Communications Manager, Enhabit + Green Building Store
We felt very proud that Green Building Store was able to support the Passivhaus conference as one of the lead sponsors this year. The Passivhaus Trust did a great job of weaving together a lot of very current issues connected to low energy building and Passivhaus that had been in my consciousness but that I had not fully understood. Kate de Selincourt gave an excellent, though sobering, overview of the health impacts of poor housing, fuel poverty and poor indoor air quality. It was also good to understand better how good ventilation can reduce the spread of airborne diseases, thanks to Mich Swainson’s talk. There were a wide range excellent in-depth technical talks – from structural engineer Beth Williams’ talk on concrete-free foundations to Mark Siddall’s talk on problems that can arise with cold roofs. The research on reduced levels of radon in Passivhaus homes, presented by Barry McCarron, was very enlightening. It was also great to understand from Chris Twinn more about why hydrogen as an energy source is not the green saviour it is being touted as. There were so many more informative talks and case studies in the Passivhaus Trust’s brilliantly-curated conference.
The most inspiring and hope-giving aspect of the conference was hearing about local authorities embracing the standard – from Exeter to Edinburgh – and our own local flagship Passivhaus scheme initiated by York City Council. The projects were largescale, ambitious and underway and it definitely showed the art of the possible to local authorities everywhere. The even larger-scale project examples from North America, presented by Bronwyn Barry of NAPHN, were also a much-welcome boost. I also really loved Harry Paticas’ film about the Retrofit Action For Tomorrow programme, sharing a retrofit educational project he is working on. The young people in the film were so switched on and made some striking comments about the urgent need for climate action (and adult inaction).