What is Passive House?
Those of us who care about climate change don’t think of ourselves as very “passive” about it. However, the green building standard Passive House is anything but! One of the most rigorous energy efficiency certifications for buildings, Passive House buildings are so airtight and well-insulated that you could heat them with a light bulb. On top of that, they provide a continuous supply of fresh air and can result in cost savings from lowered energy use. Any building can be certified as a Passive House, including houses, multifamily apartment buildings, commercial, and institutional buildings. Grouparchitect’s Gavin Erickson and Andrea Detweiler are Certified Passive House Consultants and can coordinate your Passive House project from start to finish.
There are five principles involved in building to a Passive House standard:
A Passive House building might have more insulation than a conventional building. However, what will be most different is the way that transitions, like roof-wall junction or wall-foundation junction, will be detailed. In order to achieve Passive House levels of performance, these junctions need to be carefully detailed in order to avoid thermal bridging.
An air barrier can take many forms, but always achieves the same function: keeping conditioned air inside the building and unconditioned air out. This is important both to minimize heating and cooling loads and to keep walls free of moisture.
The size of a window and the compass direction that it faces can dramatically affect the heating and cooling of a building. Shading devices can also help by blocking the hot summer sun while allowing solar heat gain in the winter.
High-Performance Windows and Doors
It has been said that installing a window is like punching a hole in the thermal envelope of a building. This can be mitigated with windows that have a high thermal resistance value, thermally broken frame, and glazing with coatings that improve performance. In general, windows in Passive House buildings are triple-paned.
In order to provide a continuous supply of fresh air without losing heated or cooled air to the outdoors, heat recovery ventilators move heat between supply and exhaust air. In the winter, heat moves from exhaust air into the ventilation air coming in, keeping the interior warm. In the summer, heat moves from the air coming in to the air moving out, keeping the interior cool. Besides reducing the heating and cooling loads that would have resulted from dumping conditioned air outside and replacing it with unconditioned air, heat recovery ventilation ensures that occupants enjoy a continuous supply of fresh air.
Give us a call to discuss how Passive House might be right for your project! More information on Passive House can also be found at phius.org.