Sustainable construction certifications can play a crucial role in mitigating climate change by establishing solid criteria to foster ecologically responsible practices in the construction industry. They not only give public visibility to industry-accepted standards and monitor performance, ensuring compliance with regulations, but also stimulate the reduction of negative environmental impacts while rewarding buildings that fulfill strict sustainability standards. By establishing higher levels of excellence in projects and constructions, these certifications influence the evolution of construction codes, training professionals, and even changing corporate strategies.
More specifically, the movement towards passive buildings has its roots in Germany, where the Passivhaus Institute formalized these principles in 1996. The central concept is to create a habitable or working space that requires a minimum amount of external energy to regulate its temperature, making it highly sustainable and economically viable in the long run. Essentially, this balance is achieved through a combination of key elements, including high-quality insulation for walls, ceilings and foundation; the construction of a hermetic envelope that avoids losses and minimizes air leaks; the use of high-performance windows and doors that eliminate thermal bridges; heat recovery ventilation systems; solar gain considerations, as well as efficient solutions for space heating and cooling; and power modeling and design optimization. These principles can be applied to all buildings, including single-family houses, multifamily buildings, schools, skyscrapers, and more.
There are several certifications available around the world, each with its own approach. Some that stand out are LEED, WELL, and many others. One of the prominent participants of this movement is Phius (Passive House Institute US), which has been seeking to establish new standards for energy efficiency through its approach to certification. Phius stands out by integrating passive construction principles with cost optimization and climate specificities. The result is the construction of buildings that demonstrate a balance between cost savings, energy efficiency, and environmental resilience, promoting comfortable and healthy internal environments. We spoke with Lisa White, Phius Associate Director, to better understand this approach.
Compared to other sustainable construction certifications, Phius introduces specific measures for passive buildings, such as airtightness and thermal comfort. But the most prominent aspect of Phius is its emphasis on the conception of buildings that reduce energy requirements from the beginning, establishing a solid foundation to achieve zero energy status. This places projects on a path to save between 40% and 60% more energy compared to conventional buildings, and with the addition of minimal initial costs. It also prioritizes adaptability and resilience, ensuring that these structures keep internal temperatures comfortable, even during power outages and extreme climate events. This inherent resilience reduces the dependence on overloaded electrical networks, improving the sustainability of these buildings in the face of the challenges caused by climate change.
As White puts it, “the five primary principles of passive building are: using continuous insulation, creating an airtight building envelope, employing high-performance windows, utilizing some form of balanced heat- and moisture-recovery ventilation, and minimizing the space conditioning system because of lower conditioning loads.”
Phius buildings implement these principles while adhering to a specific set of energy targets that take into account the building typology and climate zone of the project. This includes the recommendation of environmentally friendly materials.
This approach generated climate-specific benchmarks for heating and cooling loads in more than 1,000 locations in the United States, taking into account unique climate factors and electricity costs at the state level. They establish restrictions on annual and peak heating and cooling loads, creating an ideal zone for energy conservation through passive strategies.
Such an approach avoids excesses in the use of insulation materials and unnecessary costs, making their standards not only energy efficient, but also optimized in terms of budget and the use of materials. In addition to the third-party verification that ensures all Phius buildings meet comfort and health standards, there is also the iterative review process. In other words, instead of just assessing a building once it is complete, Phius engages with project teams during the design phase to guide them toward certification. The collaborative practice simplifies the process and promotes a deep understanding of energy-efficient design principles. This approach is intended to serve as a comprehensive guide throughout the building delivery process, ensuring that the design and construction of the building are conducted with an emphasis on energy efficiency and sustainability.
The case of Forever House, a modernization project located in Westchester County, New York, illustrates the practical application of the Phius principles. Architect Christina Griffin demonstrated the viability of sustainable living through design by transforming a 1905 cottage into an energy-efficient, fossil fuel-free housing prototype, meeting the Phius+ Source Zero standard.
Griffin's retrofit involved replacing the oil and gas burner line with electric components, including a Bradley heat pump water heater system, as well as a centralized energy recovery ventilation unit. An array of solar panels generates more energy than the house consumes, with excess energy stored in battery modules. Griffin's thoughtful design, energy-efficient appliances and well-placed windows contribute to the home's minimal energy consumption. The building's thermal envelope, with multiple layers of insulation and vapor control membranes, exceeds typical building codes. The exterior features wood detailing, expansive eaves for passive cooling and strategically angled trusses.
The Phius Certification Guide is a most valuable resource for builders and architects wishing to embark on the certification journey. With useful and essential information, it serves as a tool throughout the certification process. The Phius Resource Library also provides an extensive range of supplementary resources, including calculators, workbooks, webinars, tutorials and much more. In addition, PhiusCon will take place in Houston from November 7-10, 2023. Hosted by Phius, the conference brings together building science experts, manufacturers and attendees looking to learn and reduce the impact of buildings as a contributing factor to climate change.
This article is part of the ArchDaily Topics: Decarbonize Architecture presented by Holcim
Driven by its purpose to build progress for people and the planet, Holcim is decarbonizing building, while improving living standards for all. Holcim empowers architects and developers across all regions to build sustainably. This series explores how cities of the future can be low-carbon, circular and resilient.
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