Dwell Development takes home their first Housing Innovation Award
The 2013 Housing Innovation Awards were presented on October 4, 2013, at a breakfast ceremony during the U.S. Department of Energy (DOE) Solar Decathlon 2013 in Irvine, CA. The awards showcased a number of the Building Technologies Office residential programs under one umbrella event. View all winners.
Below is the case study for Dwell Development’s Passive House, a DOE Zero Energy Ready Home in Seattle, WA that scored HERS 34 without PV. This 2,000-square-foot system home has R-45 double-stud walls, an unvented flat roof with 2 inches of spray foam plus 18 inches blown cellulose, R-42 XPS under slab, triple-pane windows, and a ductless mini-split heat pump.
Anthony Maschmedt’s first U.S. Department of Energy (DOE) Zero Energy Ready Home is also his first Passive House, and, to his knowledge, the first Passive House built on speculation in the state of Washington. If the home performs according to expectations, DOE’s Zero Energy Ready Home will become a target for future Dwell homes. Maschmedt also plans to build more Passive Houses with the goal of eventually building every home to Passive House standards.
Like most of the homes he’s built, this one sold at the foundation stage. “Our buyers are looking for energy efficiency. We have a waiting list of people who keep an eye on our new homes,” said Maschmedt. All of his homes are built on spec, which Maschmedt prefers over custom homes, because it gives him the freedom to build homes the way he likes—and what he likes is as energy-efficient as possible.
Maschmedt started out in 2002 working for his Mother, an award-winning designer and general contractor of traditional, custom homes. In 2005 Maschmedt ventured out on his own and started Dwell Development with the idea of going modern and going green. He took the fi rst Built Green class offered by Washington State’s Master Builders Association and began building homes that achieved the 3-star rating from the Snohomish and King County Master Builder Association’s Built Green program. By 2007 every home was achieving a 5-Star Built Green rating as well as the Northwest ENERGY STAR certification. When the market crashed, Dwell Development’s homes continued to sell at premium prices.
Maschmedt’s company has grown to 6 employees (plus contractors) and he now builds about 25 homes a year, with 26 scheduled for 2013 and 27 slated for 2014.
The home in South Seattle is one of 42 homes by Dwell in a micro-community of modern, efficient homes built on an urban gray-fi eld site. One of the other homes in this community is part of a performance testing program conducted by DOE and the Northwest Energy Efficiency Alliance (NEEA), with energy monitoring by Washington State University’s Energy Extension Office.
Meeting the DOE Zero Energy Ready Home criteria was not a difficult jump, according to Maschmedt. His company was already building a double-wall enclosure. To meet their project goals they just increased the overall cavity width from 10 to 14 inches. The double-wall consists of two 2×4, 16-inch on-center framed walls. The framer built the exterior walls in his shop and brought them to the site ready to assemble.
The walls were spaced 8 inches apart, so the overall wall cavity was 14 inches wide from the OSB-sheathed outer wall to the interior surface of the inner wall, which was covered with netting to hold 14 inches (R-45) of blown cellulose. Instead of housewrap, a liquid air- and weather-resistant barrier was sprayed onto the OSB sheathing, then half-inch vertical battens were installed to provide an airspace and drainage plane behind the fiber cement siding. “Application of an exterior fluid-applied air barrier allows us to make the homes air and water tight after framing. Once the roof and windows are installed, we can work all winter long and the homes stay warm and dry inside even in the wet Northwest,” said Maschmedt.