Niall Crosson | Senior Engineer | Ecological Building Systems
Reflecting on the International Passive House Conference, Darmstadt 2016. By Niall Crosson, Senior Engineer at Ecological Building Systems and Member of the Board of Directors of the Irish Green Building Council
I travelled once again to the International Passive House Conference which was held in Darmstadt, Germany from the 22nd to the 24th of April. The International Passive House Conference (IPHC) returned to Darmstadt, for its 20th anniversary, 25 years after the world’s first Passive House was built. The conference ran over 3 days, 2 days of over 100 seminars followed by guided tours of Passive Houses in the region on Sunday. Unfortunately, I could not attend the tours but I did attend a number of the seminars over the 2 days.
It is no surprise that the sustainability and durability of this standard came to the fore in many presentations at this year’s conference. While attaining a 90% reduction in the space heating requirements is an impressive feat, to be truly sustainable this must be maintained over the long term, a fact highlighted by the founder and director of the Passive House Institute, Wolfgang Feist in his presentation.
Some key points I noted from his presentation were that the amount of energy required for space heating for the first generation Passive Houses is still an incredible 8.5 KWh/m2/year, clearly proving once again that that the “performance gap” simply does not exist when it comes to Passive House. Even 25 years later, these buildings use a 10th of the energy required for space heating compared to the average German dwelling. This is all the more impressive given the lack of availability of high performance heat recovery units, Passive House windows and doors and advanced airtightness and thermal bridging solutions 25 years ago when this building was originally built.
Many other areas of the construction were scientifically scrutinised by materials experts and building physicists, to the extent that even a portion of the 25 year old external insulation was removed and examined.
The airtightness of the envelope remained the same as it was originally, except for the requirement to replace some seals on window frames, acceptable after 25 years I suppose, especially given I have to replace some of mine after only 10 years. The thermal insulation is still performing as it did the first day it was installed. The durability of both the airtightness and thermal envelope is all the more impressive given that there have been a number of earthquakes in the region over this time.
Another impressive feature was the performance of the ventilation unit; not only in energy performance, but also in its contribution to indoor air quality, its durability and that it is still spotless, with an expected life of 50 years. To sum up it was highlighted that durability and sustainability are as important as energy efficiency. This is even more relevant today, when one considers more rapid forms of construction, demanding high levels of energy efficiency, in new builds and retrofits. The durability of the solution must be prioritised.
One of my favourite aspects of the IPHC is the willingness of speakers and attendees to share ideas and experiences about what worked well on projects and more importantly what failed and why. This was exemplified when, on two different presentations I attended, the speakers highlighted areas where air leakage occurred due to an oversight on their part, but which was remedied on site.
As I have experienced in my Internal insulation of solid masonry wall seminars with the Green Register, retrofitting buildings presents a major challenge and similar issues arise in different countries. The Passive House standard for retrofit is called Enerphit. While it is somewhat less onerous than Passive House it is still an incredibly challenging standard to attain. While external insulation of walls is often seen as the optimum solution this is not always possible. It was encouraging to see that many of the thermal solutions and steps taken for the sustainable retrofit of masonry walls with internal insulation presented at the conference are echoed in The Green Register Training Programme. Addressing thermal bridges, vapour movement, protecting walls against moisture induced issues and many other challenges were highlighted in presentations from Floris Keverling from Four Seven Five in the US and Tanja Schulz of the Passive House Institute.
50% of the attendees at this year’s conference were from an architectural background. This made Elrond Burrell’s (of Architype Ltd) presentation all the more relevant. Elrond explained how architects can drive the adoption of Passive House in primary schools in England and Wales. Elrond eloquently set out key steps as to how Passive House can be adopted more quickly based on Architypes extensive experience with delivering quality and cost effective Passive House schools. This was exemplified by the delivery of two Passive House schools at no extra cost and a third one cheaper and quicker than the two before. He also reiterated a common theme from almost every presentation I attended whether it be from a German, US, UK, Irish of Australian presenter, which was the need for collaboration. It should be early and frequent and to include everyone from the design team, contractors and even the client as integral team members. This was highlighted brilliantly by Michael Ingui of Baxt ingui Architects in New York. Michael explained how this collaboration, after some initial trepidation, has now expanded to contractors who have “meet ups” and discuss projects, details and find solutions, even though they may compete with each other to win some projects.
Following Elrond’s presentation I attended Jonathan Hines’s (MD of Architype Ltd.) presentation “Closing the performance gap in UK schools”, detailing three years of energy and comfort monitoring evidence. Jonathan’s presentation highlighted the superior levels of indoor air quality and thermal comfort in summer and winter in Passive House schools compared to conventional schools, not to mention the energy savings. Could you imagine needing only 1 small boiler for a 2,500 m2 school?
Another consistent theme in each seminar I attended was the critical role airtightness plays in ensuring thermal performance so that the building’s durability is optimised. This was clearly exemplified in Nick Newman’s (of ECD architect in London) study of the retrofit of an 11 storey 1960’s building with 107 properties. Nick stressed that the airtightness made the largest contribution to energy saving. To learn more about airtightness and how to deliver it on site the next Green Register training event, “Airtightness, Why and How” will be held on the 6th and 13th of October and on the 10th of November. More details can be viewed here.
I attended many other presentations over the course of 2 days, but one which resonated particularly with me was Monte Paulsen’s of Red Door Energy Design Ltd in Canada. Monte presented an affordable factory-built Passive House solution for the remote Canadian communities. Monte presented the project which the contractor estimated saved €325,000.00 compared to site building costs. His final slide highlighted that on the coldest night of the year each unit only required the energy equivalent of 6 100W light bulbs to maintain a comfortable living climate. For me, this is the primary benefit of the Passive House standard. It can protect the neediest in society against fluctuating fuel costs, while at the same time maintain a durable building, with a healthy comfortable living climate. This is all the more pertinent given the housing crisis we are experiencing at the moment in Ireland and other parts of the world.
This is but a fleeting glance of the IPHC. Unfortunately I couldn’t write about all the presentations I attended, and with over 100 I struggled to pick the ones to attend. It was also great to meet so many familiar faces from Ireland, the UK and all over the world, and to meet many new ones too.
It is clear that Passive House projects can be delivered in all shapes and sizes from small pods, to large multi-story buildings. It is not limited to a single form of construction either. Over the course of the event I saw projects with conventional masonry walls, timber frame, CLT, SIPS, straw bale and even rammed earth Passive Houses.
It is an incredible achievement that 175 countries have finally agreed to binding protocols with COP21, and it was a nice coincidence that this document was finally signed in New York on the same weekend as the International Passive House Conference 2016 was been held. Signing though is just the first step; the major challenge now is to deliver on and realise the promises as set out COP21 and reduce our carbon emissions. It is clear that the Passive House standard, with its 25 years of real experiences over tens of thousands of buildings is a key ingredient in making the promises within that signed document a reality.
25th April 2016