The project was part of a LEED for Homes pilot project program that was administered by Earth Advantage Institute, a nonprofit green building resource organization that has certified 11,000 sustainably built homes. Ierulli Construction, Inc. of Tigard, Oregon, built the residence.
The home is designed for indoor and outdoor living, with generous and balanced naturaldaylight interiors. The site slopes from east to west, has a grove of native Douglas firs, and enjoys excellent southern solar exposure. The new house’s footprint minimizes soil disturbance and reuses the existing driveway alignment, enabling preservation and restoration of the remnant native Northwest landscape. The design arranges interior spaces and outdoor private areas to the east and south, away from the public street, emphasizing views to the existing grove of trees and planned gardens on the property.
The house form allows for natural ventilation and utilizes passive solar heating, which is supported by an in-floor hydronic heating system. The home has a metered solar electric 2.4 kWh photovoltaic system and is pre-plumbed for solar thermal hot water. The project includes the first North American installation of a Daikin Altherma high-efficiency air-to-water heat pump, which provides hydronic heating and domestic hot water. A heat recovery ventilation system captures waste heat for the fresh make-up air, maintaining high indoor air quality.
“This home design offers a unique example of how sustainable features can work with the landscape and reduce the footprint of a residence on the land,” said Randy Hansell, LEED for Homes program manager at Earth Advantage Institute. “Constructive Form has been an instrumental player in our LEED for Homes pilot project. Their innovative work provides long-term value to both the owners and the neighborhood.”
The project is approximately 1,820 square feet. The primary living space is on one level, with a bedroom and bath to accommodate aging in place. Another bedroom and bathroom are located at a half-level above. A separate one-bedroom, one-bath space was built below the main level for use as a guestroom. A southeast outdoor living space is protected by an extended roof that expands the seasonal living area. The sloped ceilings, corner windows, large glass area, operable clerestory, and interior door transoms enhance the visual appeal of the site and provide a more spacious feeling to the efficient home. The narrow depth of the house ensures balanced natural light to all rooms. The L-shaped form creates a generous south-facing outdoor court, providing a layered transition from outside to inside and public to private areas.
All rainwater is either detained in flow-through planters or infiltrated onsite, contributing to the health of the neighborhood’s stream that supports riparian habitat. Rainwater from the metal roof is also directed into an above-ground cistern and overflows into a vegetated bioswale on the property. The access driveway was formed with a pervious concrete mix that enables the infiltration of stormwater.
The construction system uses industry standard wood framing elements with advanced framing strategies. Use of continuous headers above windows and doors, and a two-foot framing module, reduced the amount of wood used on the project and allowed for door and window openings to extend to the ceiling. On the exterior, cement fiberboard, rough sawn cedar, metal siding and roofing, and a rainscreen assembly were carefully constructed for the Northwest climate. Fir trim and millwork, as well as FSC certified eucalyptus flooring, were used in the interior, complementing the clear finished fir windows. In keeping with the clients’ wishes for superior indoor air quality, all interior finishes are non- or low-VOC (volatile organic compound).
About Constructive Form Architecture and Design LLC
Founded in 2006 by Brent Hinrichs, Simone Goldfeder, and Kina Voelz, Constructive Form Architecture and Design LLC, is based in Portland, Oregon. The founders have worked together on architecture and design projects over the last decade, with collective design experience across the United States and Europe. The firm also has international competition expertise, including a wide range of use programs with private, public, and institutional clients. Common to all of the team’s projects is an open and collaborative approach to the design process, as well as a critical interest in environmentally supportive practices, site relationships, and spatial organization; construction detailing and materials; and technical and system performance. Constructive Form is committed to providing design services that are supportive of project needs, budgets, and requirements. The team is dedicated to crafting livable places that are responsive to the region and locale.
About Earth Advantage Institute
Earth Advantage Institute works with homeowners, homebuyers, builders, and developers to bring the most energy efficient, sustainable, and healthy homes to the market. The organization is an independent, nonprofit resource group that certifies homes and communities based on conformance to ENERGY STAR®, Earth Advantage®, or LEED® for Homes standards. Earth Advantage Institute also offers education classes and has a showroom at its national center in Portland, Oregon.
About LEED® for Homes
LEED® for Homes is a third-party certification system for high performance green homes. Developed and administered by USGBC, LEED for Homes awards points to projects in seven categories of environmental performance: Location & Linkages, Sustainable Sites, Water Efficiency, Indoor Environmental Quality, Energy & Atmosphere, Homeowner Awareness, and Innovation & Design. To date, more than 540 homes have been LEED certified, and over 13,000 have been registered and are under development. For more information, visit www.thegreenhomeguide.org.