Utilizing a green building rating system is one of the most effective ways to achieve a sustainable project. Backed by decades of research, these third-party systems can reduce carbon emissions, improve occupant well-being, and increase accountability.
There are many rating systems on the market, including Leadership in Energy and Environmental Design (LEED) and Living Building Challenge (LBC). While these systems offer a holistic approach to sustainability, others focus on more specific aspects of building design and construction.
One system, Passive House, emphasizes performance and energy costs. The system can help you achieve a highly efficient, long-lasting building that maintains consistent interior temperatures.
This article will discuss Passive House design principles, the types of projects it fits, and the certification process—helping you determine if it fits your goals.
What is Passive House?
Passive House is a voluntary building standard that seeks to reduce carbon emissions and energy costs. Its techniques were initially developed in the 1970s by US designers responding to the oil embargo before gaining popularity in Europe. Today, passive building techniques are regaining popularity in the US with Phius (Passive House Institute of the US) helping lead the way.
Passive buildings often include features like:
- A highly insulated building envelope
- High-performance window glazing
- Minimal thermal bridging (heat escaping through a thermal barrier)
- Balanced mechanical ventilation to achieve superior air quality
The goal is to make the building as airtight as possible and utilize daylighting and shading techniques to keep the building cool in warmer months and warm in cooler months.
Benefits of Passive Buildings
Energy savings are perhaps the greatest selling point of adopting Passive House. According to Phius, passive building techniques can reduce energy needs by 80% in a single-family home. These techniques can get you closer to net-zero energy usage, making the transition to renewable energy more accessible.
At the same time, passive buildings are designed for longevity. They are better able to withstand climate change and natural disasters. In a power outage, passive buildings can maintain interior temperatures much longer than standard buildings.
If a standard building is a red solo cup, a passive building is a thermos.
Compared to a standard building, a passive building is like a thermos.
What Types of Projects Best Fit Passive House?
Although Passive House is traditionally associated with single-family homes, its principles fit a variety of project types, including schools, offices, houses of worship, multifamily developments, and retrofits of existing structures.
The system can increase construction costs, but building owners see a return on investment through energy savings. According to Phius, a passive building normally costs 3-5% more than a conventional home.
The cost difference decreases with building size. For a larger, multifamily development, passive building techniques are 0-3% more expensive than building to an ENERGY STAR baseline. In general, the larger the building, the smaller the cost difference.
Some larger-scale developments may struggle for certification. The larger the scale, the greater the chance for thermal bridging. There are exceptions to this rule, such as 425 Grand Concourse in the Bronx, and you will need to work with your design team to determine your project’s viability.
How Does the Certification Process Work?
Like all green building rating systems, Passive House involves third-party verification to ensure the design and construction meet the requirements. Certification begins early in the design process.
Your design team will submit initial plans to Phius for review. Phius will analyze the design, determine the project’s viability, and work with your architect to improve the building’s performance.
During the initial review and all subsequent reviews, the design team will use energy modeling software to ensure the project meets Phius standards.
The certification process continues into construction with a Phius verifier or rater, depending on the project type. The verifier will complete various tests, including a blower-door air tightness test, to ensure the building’s performance is congruent with the energy modeling done in the design process.
Learn More About Green Building Rating Systems
Green building rating systems offer a tangible return on investment. While they may increase initial project costs, they can help you achieve a higher-quality building with lower lifecycle costs.
If lower energy costs are one of your top project goals, Passive House may be a viable option. The system requires a high-performance envelope to reduce thermal bridging and maintain stable interior temperatures. Early planning, thorough energy modeling, and construction testing can result in lower energy needs.
As mentioned, Passive House is one of many rating systems available to new and existing buildings. Learn about your other options by reading about the most popular systems and the projects they best fit.