WHAT IS PASSIVE HOUSE?
Lincoln and his staff recently completed their Passive House designer certification. What is Passive House? It is a building design and construction standard that originated in Germany and is steadily gaining popularity in the U.S. and around the world. It prioritizes user health and comfort while dramatically reducing building energy use and carbon emissions.
A comfortable and healthy interior environment is achieved by focusing first and foremost on a high-performance building envelope. High levels of wall insulation, high-performance windows, and airtight construction techniques mean that very little mechanical heating or cooling is required to maintain a comfortable indoor temperature. This high level of thermal control also eliminates condensation (think 1960’s metal window frame with dew on the inside when it’s cold out), which prevents mold growth and rot and promotes the long-term durability of the building.
In response to the tight building envelope, fresh, filtered outside air is delivered constantly and silently through a low-flow mechanical ventilation system, providing optimal air quality at all times. A heat recovery unit transfers the warm or cool temperature of the exhausted interior air to the incoming fresh air so that very little energy is lost in the process. This maintains a very stable indoor air temperature, even in very cold climates.
What little interior heating or cooling may be required can typically be added to the ventilation system, maintaining a constant temperature and eliminating the uncomfortable hot and cold cycles of traditional forced-air systems. Another key benefit in the age of poor air quality due to forest fires is that the tight air sealing of a Passive House ensures you and your family have safe, clean air to breathe when outdoor air quality is bad.
Passive House is applicable to all kinds of projects- residential single family, multi-family, commercial and institutional buildings. The standardized metrics for energy use and air infiltration mean that the construction requirements will vary by climate and location, but the results will always be consistent. In the temperate Bay Area climate, for example, walls won’t need to be as thick as they would in say, the Lake Tahoe area, to achieve the same result in terms of energy use and occupant comfort.
Like other green building programs, Passive House projects get certified to officially confirm that they meet the requirements. But unlike other programs, this certification is a rigorous system performed by trained, third-party practitioners who confirm the building meets specific metrics.
When properly executed by a team of trained design and construction professionals, building to the PH standard can be expected to cost 5-10% more than typical construction for single-family homes. Because of the energy savings, the payback period for these investments can be as short as a few years. Of course, these numbers will vary depending on many factors, but the bottom line is that building to the PH standard is not significantly more expensive than traditional methods, and the benefits guarantee a financial payoff that grows over the life of the building. In temperate areas like much of California, “Almost Passive” is another option, where the building is designed to achieve most of the benefits of the PH standard with fewer additional costs and certification requirements.
LLA is ready to help you create the most comfortable, durable, and sustainable building you’ve ever experienced. Please contact us if you’d like to learn more and discuss possibilities for your project.