Swinerton, DSA Architects Goes for Gold With Mountain Project

General contractor Swinerton Builders and Dan Smith & Associates, a Berkeley-based architecture firm, are seeking a gold certification from the U.S. Green Building Council for a recently completed renovation of the Presentation Retreat and Conference Center, a 264-acre interfaith retreat in the Santa Cruz Mountains near the city of Los Gatos.

Jess Rios, Swinerton's project manager in its Santa Clara office, said that while the sustainable elements of the $3.5-million project added 10 to 15 percent to the cost of construction, it will save up to 50 percent in energy use and at least 30 percent in water needs.

Rios said the project's owner-Sisters of the Presentation, a 225-year-old Catholic religious community of women that "responds to human needs"-were involved in planning the project's green elements. "Right up front, they wanted to go green."

The project involved construction of a 9,500-sq.-ft. welcome center, bookstore and dining facility-buildings that replaced the existing dining room and kitchen, which were structurally weakened by the Loma Prieta earthquake in 1989-as well as the former entry building, which was condemned at the time of the earthquake. The overall dining capacity of 200 will remain the same.

The new Welcome Center will have a clearer site entrance for retreat visitors and provide a space for information and environmental education.

The Presentation Retreat and Conference Center serves the community by providing accommodations for up to 150 persons.

The project also addressed significant environmental and natural landscape improvements. According to the project architect, site improvements included adding more native tree species; restoring natural creeks and wetlands; creating organic gardens and compost areas; rehabilitating open areas by healing the scars of old ruins; and making a more coherent, safe, and ecological circulation route for retreat visitors by concentrating most visitor parking and car traffic at the northernmost area of the site.

Sustainable design features included a "living roof" (thin-film unisolar panels on a standing-seam roof), radiant heat through in-slab water piping, passive solar water heating, straw-bale walls (that replace traditional insulation), natural convective heating and the use of low-emitting volatile organic compound materials. The living roof contains native grasses, plants and flowers.

Swinerton also built an on-site sewage treatment facility, used recycled content products and set up a stormwater collection and storage system in cisterns. A gray water system also was built for irrigation.

The radiant heated floor is made up of fly-ash replacement concrete, which reduced lumber use by up to 50 percent.

Rios said the project's primary challenge was getting green building plans approved by the local jurisdictions-especially the Santa Cruz County Fire Department for the living roof.