While buildings account for 30% of global energy consumption, the industry has developed several approaches to limit these impacts, including so-called passive construction.
The environmental impact of buildings is colossal. They account for 30% of global energy consumption and 26% of global CO2 emissions, according to the International Energy Agency.
These emissions result mainly from heating, air conditioning, lighting, the use of electrical appliances and construction waste. But construction itself also requires significant quantities of resources such as wood, concrete, steel, and plastics. Factors such as the hauling of household waste, the extraction and processing of these resources leads to deforestation and ecosystem destruction.
It also causes air and water pollution due to the emissions mentioned above, the release of chemicals into wastewater, and waste materials containing volatile organic compounds such as paints and insulation. These processes also contribute to disrupting natural habitats and biodiversity.
Faced with the climate challenge, the industry has developed several approaches over the past few decades to limit these impacts, including so-called passive construction.
Three approaches to reducing the environmental impact of buildings
Three approaches stand out for their effectiveness and sustainability: passive construction, active construction, and bioclimatic construction. All aim to reduce the ecological footprint while improving occupant comfort.
Bioclimatic construction takes into account local climatic, geographical, and environmental conditions to design buildings that use the climate to their advantage.
Active construction, on the other hand, integrates advanced technologies to make buildings’ energy production autonomous (photovoltaic solar panels, solar hot water systems, and energy storage solutions such as batteries).
Finally, in contrast to active construction, passive construction aims to maximize energy efficiency by minimizing the need for artificial heating and cooling. It relies on the use of natural resources (sun, wind), systems such as advanced insulation, triple-glazed windows, and mechanical ventilation systems with heat recovery. It is this latter approach, initially conceptualized in the 1970s, that we focus on here.
75 to 90% less CO₂ emissions
Its history dates back to the 1970s, when the 1973 oil crisis raised awareness of the limits of fossil resources and encouraged the search for sustainable solutions. Initial developments in passive construction sought to create economically and energy-efficient buildings by optimizing comfort and air quality at an affordable cost. In 1991, the first passive building was erected in Darmstadt, Germany, following three years of research led by Wolfgang Feist.
Since then, passive construction has consistently demonstrated its environmental effectiveness. According to the EPA, these buildings now save up to 90% of energy for heating and cooling compared to traditional construction, reducing CO2 emissions by 75 to 90%.
This performance is due to advances in insulation, heating, ventilation, waste management and lighting, as well as the use of more sustainable materials such as FSC (Forest Stewardship Council), certified wood and innovations such as EMERWALL’s sugarcane bagasse-based insulation panels. The integration of renewable energies such as solar, wind, and geothermal energy into building design has also grown significantly.
The emergence of environmental standards such as LEED and BREEAM has also encouraged the deployment of sustainable construction practices. Growing awareness of environmental issues has stimulated demand for green buildings, leading to investments in environmentally friendly technologies and innovative architecture. These efforts are supported by government policies, such as Wisconsin environmental regulations, business initiatives, and increased citizen engagement for a more sustainable future.
It applies to new or renovated buildings: single-family homes, multi-family housing, educational buildings, offices, and public buildings. A Passivhaus-certified building is distinguished by its extremely low energy consumption, which is ensured by three fundamental principles:
- very low heating requirements,
- a very airtight building envelope,
- low total primary energy consumption.
These buildings are highly insulated, perfectly airtight, and equipped with dual-flow ventilation systems with heat recovery, ensuring optimal indoor air quality and minimal energy consumption.
The certification imposes strict criteria: heating requirements must not exceed 15 kilowatt-hours (kWh) per square meter per year, regardless of altitude or climate, and the airtightness of the building envelope must limit air loss to less than 0.6 times the envelope volume per hour, verified by a blower door test.
Total primary energy consumption must also not exceed 120 kWh per square meter per year. This figure includes heating, hot water, ventilation, lighting, and electrical appliances. Another important aspect is controlling overheating, which should not affect more than 10% of annual hours in order to maintain occupant comfort without exceeding 25°C indoors.
Long-term economic benefits
Passive buildings thus contribute not only to the preservation of natural resources but also to the creation of a more sustainable and comfortable built environment.
Despite potentially higher initial costs, the energy savings achieved allow for a rapid return on investment. Scientific studies show that the total costs of a passive building can be lower than those of a conventional building in the early years, highlighting the long-term economic benefits of this construction approach.
The principles of passive construction, which are part of a long tradition of energy savings and environmental friendliness, continue to be developed and refined today. Combined with innovations in materials and technologies, it provides the industry with a strategic response to climate challenges.
