Sweetwater Spectrum | Sonoma, CA

Recognizing a need for housing support as their children with autism advanced into adulthood, a group of Northern California families combined forces to conceptualize the Sweetwater Spectrum community for adults with autism. The residential community, created in 2009 as a pilot that could be replicated throughout the U.S., was designed to help residents establish a familiar, comfortable and manageable environment that would also nurture their independence. Shared housing, a community center featuring several amenities, indoor and outdoor gardens, and a welcome and volunteer center were combined into the Sweetwater Spectrum community concept to provide a comprehensive long-term living environment for residents.

The Sweetwater Spectrum community design also incorporates several sustainable building, renewable energy and general resource management elements that additionally reflect the goals of minimizing sensory overload for residents while creating a peaceful environment that connects them to the natural cycle of the day. Maximized daylighting, solar-thermal systems and non-VOC building materials were among numerous elements specified by the project’s San Francisco-based architecture firm, Leddy Maytum Stacy (LMS) Architects, to achieve the melding of universal design and sustainable building goals.

“We needed to offer real clarity in design, to allow residents the ability to preview situations and make choices on how to engage with other individuals in the community,” says Marsha Maytum, FAIA, principal of LMS Architects.

As part of this aim, combined radiant heating and cooling systems were specified for the 3-acre property’s four 4-bedroom, 3,250-square foot homes, which would accommodate all 16 residents in the community. A similar system was also specified for the 2,290 square foot community center.

“Controlling all sensory aspects of the living environment to the best of our ability was key to this project, particularly as we wanted to establish a successful model that could be replicated to address the need for this type of community across the country,” said Mark Jackson, president of Sweetwater Spectrum. “Including quiet, efficient HVAC systems in the residents’ living spaces and recreation area was part of the way in which we sought to achieve this goal.”

Mechanical contracting firm Reid Heating & Energy expanded on mechanical engineer Timmons Design Engineers original specification for radiant heating systems across all buildings on the property by incorporating a hybrid radiant heating and cooling system from REHAU. The updated design called for 9-ton hybrid heating and cooling systems with RAUPEX^® crosslinked polyethylene (PEXa) pipe from REHAU, as well as REHAU INSULPEX^® pre-insulated pipe for the distribution of heated and chilled fluid generated from two air-to-water heat pumps installed in each individual home and in the community center. The project was also designed with actuators that would facilitate customized, zoned climate control, providing heating or cooling only when a pre-programmed thermostat in each zone senses its need.

“As this was already going to be a radiant job, we were compelled to bring some of the latest and greatest in hybrid radiant heating and cooling, as well as energy transfer, available from REHAU,” said Bob Reid, president of Reid Heating.

Reid Heating & Energy installed a total of 18,312 feet of 1/2-inch O₂ Barrier RAUPEX pipe in the four residences, along with eight REHAU PRO-BALANCE^® manifolds to accurately balance circuit flow rates and facilitate the zoned control of each system. The firm additionally installed a total of 3,515 feet of 1/2-inch O₂ Barrier RAUPEX pipe and seven PRO-BALANCE manifolds in the community center building.

“While this was not our first experience with installing a hybrid radiant heating and cooling system, it was our first time integrating it with an air-to-water heat pump energy source,” said Reid. “We were glad to be able to rely on a foundation of nearly two decades using REHAU products and services. REHAU provided a piping circuit layout that ensured the accurate and timely installation of the radiant piping system, and the company’s exceptional support on this project was consistent with all of our experiences to date.”

Nealson additionally shares that the sustainable elements of the project extend beyond its construction and into areas including an on-property orchard and garden, which will be used to supplement the community’s food needs.

Designed to the U.S. Green Building Council’s (USGBC) LEED® Gold standards, the community at-large is expected to consume 30 percent less energy than Title 24 requirements.

“When we factor in our additional solar PV system leased from California Clean Energy, we expect the property’s total electric bills to be less than $25 per month per resident,” said Jackson. “The total combination of energy-saving technologies, including the automated HVAC control systems that will also make life easier for residents and staff, has facilitated Sweetwater Spectrum’s selection by PGE as a pilot community for its Net Zero Energy program. We’re very excited about this opportunity, as well as by the calls we receive every day from families all over the world who are eager to replicate our community-based housing model.”