First Zero Energy Multi-Family Project in Portland

Neighborhoods like The Oaks at Rose Villa prove that Zero Energy homes are entirely possible today, and that the building industry can play an important role in reversing climate change. Photo by Bill Purcell Photography.

The ﬁrst of its kind in the Portland senior living marketplace, The Oaks Zero Energy Neighborhood at Rose Villa is a 12-home neighborhood of residences designed to meet their own energy needs through a combination of ultra-energy-efficient design and on-site renewable energy generation.

The Oaks is a neighborhood within Rose Villa, a cottage community for senior living set on 22 acres along the Willamette River, designed and built by the Portland-based design build firm Green Hammer. The 12 Zero Energy craftsman-style homes are built to meet Passive House principles that support health and energy efficiency. Residents will likely have low-to-no energy costs while enjoying comfortable, quiet homes with fresh, filtered air.

"Rose Villa is committed to creating a robust community with many opportunities for residents to live their social and environmental values," says Vassar Byrd, CEO of Rose Villa. "We've created an independent and welcoming culture that embraces and celebrates diversity. For eco-minded individuals, The Oaks stands out as a unique and innovative approach to sustainable living."

In 2016, Rose Villa completed a $60 million campus redevelopment, including 75 new homes and "Main Street"—a village center with restaurants, a garden store, a rooftop deck, a spa and more. The residences within The Oaks—each about 1,200 square feet—are organized as triplexes clustered around a central courtyard. The project, which commenced construction in December of 2017, sold out prior to build-out—a testament to the demand for sustainable senior living options in the market.

"Neighborhoods like The Oaks are proving that Zero Energy homes are entirely possible today," says Stephen Aiguier, Green Hammer Design Build founder and president. The firm is just one of 10 in the nation meeting the goals of the American Institute of Architects' (AIA) 2030 Commitment, a voluntary path toward carbon neutrality in the built environment. With mounting evidence showing that governments must act with greater urgency to address global warming, initiatives such as the 2030 Commitment show that the building industry must and can be part of the solution.

At Rose Villa, the 12 homes within The Oaks pocket community are designed to significantly minimize environmental impacts through the following measures:

The homes incorporate a super-insulated, airtight building envelope for improved comfort that reduces the heating and cooling load by nearly 90 percent.
Fresh, filtered air is continuously supplied to bedrooms and living spaces and extracted from bathrooms and kitchens through heat-recovery ventilators.
State-of-the-art, energy-efficient, transcritical carbon dioxide (CO2) hot water heat pumps are used to cut energy use by half from the next-highest performance options currently on the market. A transcritical heat pump uses CO2as the refrigerant, which also reduces the global warming potential of the system, compared to standard refrigerants.
LED lighting and ENERGY STAR appliances throughout significantly reduce energy use.
All buildings have triple-paned, tilt-turn operable windows for improved comfort and performance. They block out sound while allowing for plenty of natural light and fresh air.
Advanced framing techniques reduce lumber use by 15 percent and reduce insulation voids, increasing energy efficiency.
A rain-screen wall system increases the longevity of materials by preventing moisture from entering the wall cavity.
WaterSense-certified showerheads, faucets, and toilets significantly reduce water and energy use.

With the completion of The Oaks, Rose Villa is preparing for its third and final redevelopment project in 2020, culminating in the construction of a next-generation 24-hour long-term-care neighborhood along with more independent-living homes and a second Zero Energy housing project in partnership with Green Hammer.