The recent boom in Passive House technology is beginning to make the City of Portland’s ambitious carbon emissions reduction goals seem a lot more doable.
Our town has long been recognized as a national environmental leader. For the past few decades, a host of green features – things like the bottle bill, the urban growth boundary, bountiful bike lanes, MAX light rail, and a rich tapestry of walkable neighborhoods – have placed Portland at the vanguard of sustainability in the United States.
So it should come as no surprise that the City leads the nation in pledged carbon emissions reductions. The current goal is to reduce total carbon emissions to 40% below 1990 levels by the year 2030, no small undertaking given the major population growth projected for the metropolitan region during the same period.
Of course, given the severity of the global climate change threat, we need to be working toward goals like these. But how do we achieve success? Transportation reform, land use changes, and technology improvements are all key pieces of the puzzle, surely. But a big part of the solution has to be energy efficiency in housing. After all, fully 40% of the nation’s carbon emissions come from our buildings.
And in the world of energy-efficient housing, Passive House is the gold standard. What is a Passive House? A structure that employs a simple set of building technologies to achieve big energy efficiency gains. Really big. In fact, consumption is cut by 80-100% compared to conventional buildings. In a climate like Portland’s, one of these homes can be fully heated all winter long with a heater the size of a hair dryer.
Just what the climate doctor ordered.
How do these homes scale such great efficiency heights? By creating an airtight building envelope, super-insulating that envelope, and employing heat-recovering mechanical ventilation that circulates in fresh air while capturing the heat of exhausted air. When you compare this relatively straightforward approach to the Byzantine measures required for LEED projects, Passive House shines as a triumph of simplicity over complexity. The results are impressive – comfortable, healthy living environments that require a tiny fraction of the energy use of conventional homes.
Today, Portland has become an epicenter of Passive House development, with several projects already in the ground, including two just featured by the City of Portland’s Build It Green! Home Tour. The most recently completed Portland project – Core Haus – sold at an affordable price point comparable to other homes in its neighborhood, demonstrating that the technology isn’t inherently expensive to build. That’s a good thing, because if Portland is to have any hope of reaching that 40% reduction in carbon emissions by 2030, we need to transform the way our buildings function at all tiers of the market. We simply can’t afford to build leaky houses anymore.
The Passive House page on our website contains more detail on the technology as well as links to case studies presented by Passive House US. Please check it out!
-Zack
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