The 5 Elements of Passive House Design
Passive House is a holistic approach to green home design, using five interconnected elements that work together to save energy.
1. Superinsulated Envelopes
The outside walls, roofs, and floors make up a house’s building envelope, which separates the interior of a house from its exterior. In Passive House design, the areas between the building envelope and the house’s interior space, ceilings, and floors are superinsulated with continuous insulation that wraps the house completely — with as few gaps as possible — to keep warm or cool air inside.
A Passive House envelope uses much more insulation than a typical envelope, providing greater soundproofing, improved durability, and greater building resiliency — including the ability to maintain interior comfort for extended periods of time, even when there’s a power failure.
2. Airtight Construction
A house’s air barrier is a layer of material — such as membrane, tape, and seals — around the building envelope that restricts the movement of air into and out of the building. Passive House design requires a house to meet strict air leakage standards so a continuous air barrier is baked into the plans by our expert Passive House architects.
Gaps in the air barrier can lead to increased energy use, cold air drafts, and condensation problems. While air exchange is necessary for ventilation and providing fresh air, it’s far more effective to control air exchange by tightening the envelope and using mechanical ventilation. To ensure that the air barrier remains intact and the envelope performs as designed, crews perform blower door tests throughout the construction process.
3. Eliminate Thermal Bridges
When a wall, balcony, vent, or other material bypasses the insulation, it creates what is called a thermal bridge. This often happens at points of transition — where windows meet walls, where walls meet balconies, and where walls meet at corners.
Thermal bridges are weak points in a house’s thermal envelope. Passive House design aims to avoid thermal bridging to decrease the likelihood of cold spots or mold growth near windows. By eliminating or minimizing thermal bridging, Passive House design helps ensure the effectiveness of the building envelope so the space is more comfortable and more energy efficient.
4. High-Performance Windows
Walls typically make up the largest portion of a house’s façade, but the glazing system (windows and windowed doors) can play an even bigger role when it comes to energy conservation.
Because windows are typically the weakest parts of a building envelope, Passive House design incorporates high-performance windows with triple-layer panes sandwiching layers of insulating gases, insulated frames, and other features that reduce the flow of heated or cooled air. Passive House design also positions windows to take advantage of solar heat in the most efficient way possible for each building site.
5. Heat Recovery Ventilation
Because Passive House projects are airtight, a high-performing ventilation system plays a crucial role in air quality, bringing in fresh air and moving odors, pollutants, carbon dioxide, and moisture out of the space.
A heat recovery ventilator (HRV) continuously extracts heat from outgoing air and transfers it into incoming air without directly mixing the airstreams together, ensuring that heat is not completely lost to the outside. Passive House projects recover at least 75% of this heat, leading to big energy savings. In some climates, an energy recovery ventilator (ERV) is used instead to transfer both heat and moisture to the incoming airstream.
Our Team Is Primed To Support Passive House Certification Of Your Project
AT Artisans Group, we have two Certified Passive House Consultants (CPHC), a Certified Passive House Builder (CPHB), and several talented energy modelers who can help you obtain the right documentation and navigate the Passive House certification process.
Although we don’t certify every project, we encourage certification because it leads to greater quality control; when your project is certified, a third-party verifier oversees construction to ensure that all of the Passive House elements are in place.
Passive House Can Help You Meet Other Sustainability Standards
Passive House design meshes with other project standards to help you meet your environmental building goals for sustainable residential architecture.
A “net-zero” structure strikes a balance between the amount of greenhouse gasses it produces and the amount it consumes. With the addition of onsite renewable energy, Passive House structures meet this standard, which drastically reduces their impact on the environment. Passive House can be an effective way to decrease overall greenhouse gas use.
Living Building Challenge
Living Building Challenge is a certification program that encourages sustainable, regenerative built environments — including homes, office buildings, community spaces, landscapes, and neighborhoods — all around the world.
It requires compliance in seven areas: place, water, energy, health and happiness, materials, equity, and beauty. Passive House structures can enhance Living Building Challenge projects, enabling your project to meet, or even exceed, your goals.
LEED certification addresses climate change by encouraging structures that put out fewer carbon emissions, operate with improved efficiency, and maintain healthier indoor environments. Passive House design dovetails with these goals, acting as the perfect vehicle for LEED projects.
We help Washington State residents meet standards for Built Green certification, a program that verifies through a third party that a project reduces energy use at various levels, down to net-zero. Passive House design can help you meet Built Green goals.
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