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Why 20 by 2020?

To avert dangerous climate disruption we need to shift architecture, engineering, and construction to zero net carbon (ZNC) building.  You can help lead this shift by joining the 20 by 2020 Building Challenge.


The good news is that ZNC buildings can make economic sense today. Passive House construction is a cost-effective means to revolutionize building energy performance, particularly for larger buildings. Many of the pioneering Passive House buildings in the US have been affordable housing projects.

By establishing an ambitious energy target and using science-based design and modeling, Passive House buildings reduce energy consumption by as much as 75%. Couple this with rooftop solar or a contract for green power, and you’ve got a ZNC building.


The 20 by 2020 Building Challenge will provide “proof of concept” that Passive House can propel our shift to a carbon-sustainable future.

Read more about Passive House

Benefits of Joining the Challenge
  • Identification as a change agent and market leader.

  • Promotion on the 20 by 2020 website and in media campaigns.

  • Recognition at events and in communications by King County and Challenge partners.

  • Preparation for Washington's regulatory requirements as energy code progresses to Passive House-levels of building performance by 2030.

Assistance + Incentives

The City of Seattle offers expedited permitting (Priority Green Expedited) and zoning incentives (SDCI Director’s Rule 20-2017) for Passive House. Seattle City Light’s Energy Efficiency as a Service program provides utility payments to investors in building efficiency, providing building owners with a new revenue stream for Passive House projects. Outside Seattle, various municipalities in King County are considering new Passive House policy and incentives.

Participation Requirements + Process

To enroll, applicants submit a pledge letter with project details and images. To achieve the Challenge, applicants must have, by December 31, 2020, submitted a letter of commitment and evidence of: (1) building permit submittal; and (2) Passive House performance modeling results by a certified professional showing compliance with Passive House targets (PHIUS or PHI); and 3) confirmation that the project is 20,000 square feet or larger and sited in King County.


Alternative Eligibility

Buildings that are certified as zero energy by Built Green or ILFI are also eligible to participate. Contact Kelsey Brokaw at Built Green, and Andrew Lee at ILFI for more details.

20 by 2020 Building Challenge Partners
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