The History and Significance of Passive House for Climate Action
I thought it might be useful to pull way back for the uninitiated and give some context around Passive House and why it has guided the work of OFA for decades. For those of you who are just discovering us for the first time, a brief history of the Passive House (PH) movement is in order. Most broadly the PH standard represents one of the most rigorous voluntary energy performance standards in the design and construction industry today. Its origins, development, and growing global significance are deeply intertwined with the broader narrative of climate action and the urgent need for sustainable building practices to mitigate the impacts of climate change.
The concept of the Passive House standard traces back to research and experiments conducted in the United States and Canada in the late 1970s and early 1980s. Harold Orr, a world-renowned environmental engineer, was one of the principal designers of the 1977 Saskatchewan Conservation House, the building credited with being the catalyst behind the Canadian R-2000 program as well as the global Passive House movement. However, it was in Germany, in 1990, that the physicist Dr. Wolfgang Feist, in collaboration with Professor Bo Adamson of Sweden, officially developed the Passive House standard after visiting the Saskatchewan Conservation House. The first dwellings to meet the Passive House Institute’s (PHI’s) standard were built in Darmstadt, Germany, in 1991, and demonstrated that it was possible to dramatically reduce energy consumption in buildings without compromising comfort or requiring conventional heating systems, in fact, the common follow up statement to this is that “….a Passive House can heat itself with a lightbulb”. This was one of the lines, as we were just beginning to educate ourselves on Passive House, that originally excited us but quickly confounded us. It’s helpful to keep in mind that Germany has (or at least, 25 years ago “had”) no real need for air conditioning and dehumidification, and therefore cooling was not even part of the energy modelling software the Germans were developing. It became very clear to us, very quickly, that we, in the US, with a wide range of climate zones, would need both active cooling and dehumidification, as well as much more than light bulb to heat our homes. And while that one sticky issue took us, but mostly PHIUS, years to figure out, the fundamental principles of PHI were sound.
The Passive House standard is built around five key principles: superinsulation, thermal bridge free construction, airtightness, high-performance windows and doors, and balanced ventilation with heat recovery. These principles work together to minimize heating and cooling demands, reduce carbon footprints, and create living environments that are comfortable, affordable, and sustainable. A Passive House building consumes up to 80% less total energy than conventional buildings, a testament to its efficiency.
The significance of Passive House in the context of climate action cannot be overstated. As mentioned in other blogs, buildings are responsible for approximately 45% of global energy consumption and a similar proportion of CO2 emissions. By drastically reducing the energy demand of buildings, the Passive House standard directly addresses one of the largest sources of greenhouse gas emissions. Furthermore, as the energy mix becomes greener with more renewables, Passive House buildings are well-positioned to become Net Zero or even Net Positive energy buildings, contributing more energy to the grid than they consume.
Since its inception, the Passive House standard has seen growing adoption around the world, adapted to various climates from the cold regions of Scandinavia to the tropical climates of Southeast Asia. This adaptability underscores the universal applicability of its principles, regardless of geographical location. International bodies like the International Passive House Association and regional groups in North America (ie PHIUS), Europe, and Asia have been instrumental in promoting the standard, providing certification, and sharing best practices.
Despite its benefits, the adoption of the Passive House standard faces several challenges, the greatest of which is the perception that a Passive House building requires high upfront costs. This perception is beginning to change as more and more PH buildings are finding creative design and construction strategies to reduce costs. OFA has routinely designed and built our PH projects at little to no premium, but more generally, a lack of awareness, and resistance to change among construction professionals and policymakers are the most significant barriers. However, as the impacts of climate change become increasingly apparent, there is a growing recognition of the need for carbon neutral building practices. Governments and organizations worldwide are beginning to incentivize energy-efficient construction, and the Passive House standard is often at the forefront of these discussions. Brussels, the seat of the European Union, is maybe the best example of this. In 2004, with the help of PH architect and activist Sebastian Moreno-Vacca, the government initiated a competition which incentivized building to the Passive House standard and by 2014, all new buildings and major renovations in the city were required to meet the PH standard. Similar legislation using the PH standard as a guide was introduced in 2015 in NYC, through Mayor DeBlasio’s climate action plan One City: Built to Last. Local Law 97 passed in 2019 requires most buildings over 25,000 square feet to meet PH level energy efficiency standards and greenhouse gas emissions limits with stricter limits coming into effect in 2030.
Beyond just energy savings, Passive House buildings offer improved indoor air quality, resilience to climate change-induced temperature extremes, and a pathway towards energy independence. As the world seeks solutions to reduce carbon emissions, the principles underlying the Passive House standard provide a proven blueprint for sustainable construction.
Innovation and technology have played crucial roles in the evolution of Passive House. Advances in materials science have led to better insulation materials, more efficient windows, and more effective ventilation systems. Similarly, computer modeling and simulation tools have become invaluable in the design phase, allowing architects and engineers to optimize Passive House buildings for their specific contexts. As technology continues to advance, it is likely that the Passive House standard will become even more accessible and cost-effective.
The global landscape is dotted with Passive House success stories, from residential buildings to schools, office buildings, and even entire neighborhoods. These projects demonstrate not only the versatility of the Passive House standard but also its potential to transform the built environment. For example, the Bolueta building in Spain, one of the tallest Passive House certified buildings in the world, showcases how high-density urban housing can achieve exceptional energy efficiency. Similarly, the Cornell Tech Residential Tower in New York City highlights the standard's applicability in skyscrapers and its role in reducing the carbon footprint of urban centers.
Looking forward, the role of Passive House in climate action is likely to grow. As countries commit to reducing carbon emissions and achieving net-zero targets, the principles of Passive House offer a clear and effective path towards carbon-free construction. Moreover, the Passive House standard is evolving, with new certifications like Passive House Plus and Passive House Premium recognizing buildings that produce renewable energy in addition to meeting the original efficiency criteria.
In conclusion, the history and development of the Passive House standard reflect a broader shift towards sustainability and climate action in the built environment. By focusing on energy efficiency, comfort, and affordability, Passive House has set a high bar for what is achievable in sustainable construction. As the world grapples with the urgent need to reduce greenhouse gas emissions, the principles and practices of Passive House offer a proven, scalable solution. The challenge now is to accelerate its adoption, innovate to overcome barriers, and ensure that the built environment contributes positively to the planet's future.
