Passive House: Building a sustainable future

25 Nov 2019

Against the background of climate change and increasing environmental awareness, new build construction is booming in some regions, while others face the challenge of retrofitting whole districts. In short: there has never been a better time to future-proof our building stock. The recent 23rd annual International Passive House Conference in Gaobeidian, China not only highlighted the international applicability of the Passive House standard, but also the enormous opportunity it presents to reduce CO2 emissions in the building sector.

Indeed, the more buildings retrofitted or constructed to the Passive House standard, the more significant the energy savings reaped. Not only that, energy efficient construction offers the opportunity to create new jobs in manufacturing, design and construction. Thus, Passive House buildings are an important contribution to both climate protection and a strong economy.

The Passive House standard, as promoted by the Passive House Institute and the International Passive House Association, is a performance-based, envelope first building standard that is proven to reduce heating and cooling demand in buildings by up to 90 percent as compared to a conventional building. This radically reduces the operative emissions in buildings and is applicable to new builds and retrofitting projects across all climates and regions worldwide. This is achieved through a careful planning and design phase, which considers the five principles of Passive House: airtightness, high-quality windows, climate-applicable insulation, avoidance of thermal bridges and sufficient ventilation. When these principles are properly implemented according to the local climate, the Passive House criteria, which are rooted in building physics, are attainable.

The Passive House standard can be achieved in any type of residential and non-residential building types; including high-rises, indoor swimming pools, hospitals, schools and factories. “Passive House” is not a brand name, nor is it a design style; rather it is a public standard that prescribes a set of cost and energy efficiency-optimised criteria to achieve a highly energy efficient, sustainable building. This means Passive House buildings can be designed to suit the regional architectural style and use local building materials.

The associated benefits of building better, are not limited to environmental and cost benefits. Certified Passive House buildings achieve a high level of comfort, as they are optimally insulated for the local climate and avoid thermal bridges that can lead to draughts. Instead, fresh air and a consistently comfortable temperature are maintained by a ventilation system with heat recovery. Passive House buildings are built to last, unaffected by moisture-damage and the mould build-up it can cause. This is due to their proper airtight planning and execution, as well as the use of high-quality components. Their extremely low energy demand enables renewable energy to optimally meet the energy needs of the building, thus reducing carbon emissions and incentivising local energy generation. This efficiency first approach has the financial impact of reducing energy infrastructure costs and empowering local communities, as well as reducing the energy dependence and energy bills of the building owners.

Despite varying occupant behaviour, there is no “performance gap” in the Passive House buildings, due to rigorous planning procedures and energy balance calculations performed using the Passive House Planning Package (PHPP). Indeed, the very first Passive House constructed in 1991 proved that by adhering to the Passive House Standard with its transparent and verifiable quality assurance procedures, it was still performing as designed, 25 years later. This means that from the very beginning, Passive House buildings have proven they perform as planned: saving considerable amounts of energy and reducing greenhouse gas emissions.

While construction costs vary from country to country and depend largely on the availability of qualified professionals and suitable components, they are said to be around 5-10 per cent more than a conventional building. However, there are now a number of Passive House projects that have been constructed with the same budget as a conventional build, and it is significant to note that the operating and maintenance costs in Passive House buildings are significantly lower. Indeed, a whole life cycle cost analysis has proven that even if a Passive House building costs slightly more to construct, it would still have lower life cycle costs than conventional buildings.

According to the International Energy Agency, buildings alone make up 36 per cent of global final energy consumption and nearly 40 per cent of total direct and indirect CO2 emissions. However, it is a sector for which proven solutions already exist. The Passive House standard is not only internationally applicable, has no performance gap and significantly reduces operating costs and emissions, it also supports the uptake of renewable energy. This plays a major role in achieving the goals set out in the Paris Agreement, keeping global warming well below 2°C. As Diana Ürge-Vorsatz, member of the Intergovernmental Panel on Climate Change, said in her presentation during the Passive House Conference: “Passive House is one of the rare solutions where you can have your cake and eat it too". 

The Passive House Institute with its headquarters in Darmstadt, Germany, is an independent research institute for highly efficient use of energy in buildings. The Institute, founded in 1996 by Dr Wolfgang Feist, holds a leading position internationally with regard to research and development in the field of energy efficient construction. It developed the Passive House standard and works to expand the knowledge of it by developing tools to support implementation; offering professional training and course material for a range of industry stakeholders; certifying components and buildings for quality assurance; and communicating the importance of energy efficiency in buildings.

Giorgia Tzar
manages the International Passive House Association (iPHA), communicating with stakeholders worldwide on Passive House principles and policy. Since joining iPHA in 2017, she has worked on EU projects, including Train to nZEB and Sinfonia and regularly speaks at events on policy issues, including COP24, EU Sustainable Energy Week and as a member of the Global Alliance for Building and Construction and Group of Experts on Energy Efficiency for the UNECE.