Photograph by Rebecca Hale, National Geographic
Great Energy Challenge Innovator: Habitat for Humanity of Washington, D.C.
Project: Passive house construction for low-income residents
Location: Northeast Washington, D.C., United States
Summary: Habitat For Humanity of Washington, D.C. (DC Habitat) is constructing six passive row houses in the Northeast quadrant of Washington, D.C. The chosen location is ideal to showcase an extremely energy efficient method of building science in proximity to policy-makers. While the Passive House standard is well established in Europe, it is still very new in the U.S. This technology is an optimum opportunity to make a serious reduction in energy consumption for the building sector. (See a related feature with video about the homes: Thermos-Like Passive Homes Aggressively Save Energy)
Passive housing will provide the low-income families served by DC Habitat with an ability to consume significantly less energy overall and to greatly reduce their water usage. These benefits will not only save the homeowners money, but will empower them to create a more sustainable lifestyle. The passive house model embodies Habitat for Humanity's vision that all people deserve safe, affordable and sustainable homes. (See related blog post: "Laying the Foundation for Sustainable Housing in D.C.")
Passive House is a performance-based house design system that from a building science perspective is simple and clean. The major components of Passive House Design include a super insulated thermal envelope that eliminates all thermal bridging elements that conduct heat and cold transfer between the exterior and interior of the home. The super insulated envelope is also airtight, which greatly reduces heating and cooling losses due to convection. An Energy Recovery Ventilator (ERV) acts as a proper circulation or ventilation system to evacuate stale and moist air build-up and replace it with fresh air from the outside.
These optimum building science components are expected to maintain a comfortable temperature range of 64 to 77 ºF, almost obviating the need for supplemental heating and cooling. Energy savings for the Passive House are projected to lower utility bills by as much as 75-90%. There will eventually be the option to install PV panels. Finally, DC Habitat will provide homeowner training as part of their sweat equity education.
DC Habitat has served nearly 300 families with in D.C. and outside the US through tithes to Haiti, Kenya, Kyrgyzstan and Senegal. These tithe dollars have helped to build approximately 80 simple, decent homes in these countries. DC Habitat serves district families that fall within 25-80% of area median income (AMI). The last 56 families have averaged 29% AMI. The types of people that make up the heads of households of our Habitat families include, cab drivers, housekeepers, government employees (clerical), teachers, healthcare service workers, etc. We provide low or no interest loans combined with volunteer construction, gift in kind donations and as much subsidy as we can locate in order to sell the home at an affordable price, well below market rate.
Goal: Provide low-income homeowners with extraordinarily energy efficient homes and raise awareness of home building strategy with revolutionary energy-saving technology
Project participants: Habitat for Humanity (Susanne Slater, president and CEO; Heather Phibbs, director of communications)
The Great Energy Challenge grant program, in collaboration with a distinguished group of scientists acting as the board of advisors, awards roughly a half-dozen grants per year. The goal of the grant program is to hasten the growth of promising, global energy solutions as a response to climate change, energy resource constraints and environmental limitations.