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San Diego Mayor Murphy Leads Effort at Sustainable Building Technologies

August 30, 2004

"It's not easy being green"... those words ring as true as ever when cities across the nation are looking at huge budget shortfalls and competing priorities. One ray of sunshine is being able to improve energy efficiency, improve indoor and outdoor air quality, reduce greenhouse gas emissions, and have a return on investment of less than three years! When Dick Murphy was elected Mayor of San Diego in 2000, he set out 10 goals to help make San Diego "A City Worthy of Our Affection". Included in these is Goal #9, "Pursue Energy Independence", which seeks to make San Diego less dependent on outside energy sources through energy conservation and renewable energy.

In pursuing energy independence, it is important to keep in mind that existing buildings and the building development industry consume nearly half of the total energy used in the United States. The City of San Diego's commitment to become increasingly efficient with resources, including energy, water, and materials associated with construction projects, is demonstrated in the City's first "Green Building", which is the administrative center for the Environmental Services Department located on Ridgehaven Court, hence the nickname "Ridgehaven Green Building".

The Ridgehaven Green Building is truly a sustainable building. Not only does it use 60% less energy than before being retrofitted, it also uses 50% less water and provides a healthy workplace for employees. Energy savings have been accomplished through energy-efficient lighting, occupancy sensors, reflective window film, daylight sensors, and a computer-controlled, highly efficient ventilation system using water source heat pumps. The building conserves water with low-flow toilets, sensors controlling water flow in sinks, and landscaping using drip irrigation and drought-tolerant native plants, a strategy known as xeriscaping. The colorful exterior complements the healthy interior, where building materials were chosen not only for their recycled content and recyclability, but also for their non'toxic composition. In many aspects, including energy use, recycling and waste reduction, water conservation, and harmony with the surrounding environment, Ridgehaven is a model of sustainability.

The building also serves as an environmental education venue for San Diego community groups and other visitors. It houses San Diego County's only Environmental Library specializing in environmental topics. A composting garden features commercial and homemade composting bins, and examples of vermicomposting (i.e., using worm) systems. Free composting seminars are provided to the public. In the spirit of "reduce, reuse and recycle" all furnishings, art, and displays are created with recycled materials and products.

Constant improvement and innovation are the norm at sustainable buildings like Ridgehaven. Improvements in the ventilation system such as the use of Spirotherm air-and dirt separators and upgrades to the Tracer Summit Direct Digital Control system have improved overall efficiency, and Ridgehaven was selected as a site for the U.S. Green Building Council's LEED for Existing Buildings Pilot program.

Clean Air, Clean Energy: Renewable Energy in the City's Sustainable Buildings

Along with the clean indoor air, Ridgehaven now produces clean power with its 49kW AC rooftop and 4kW carport photovoltaic (PV) arrays (picture) providing power when it is most needed at peak times. Over the 25-year lifetime of the system, the Ridgehaven solar arrays will reduce emissions of carbon dioxide by almost 480 tons, which is equivalent to planting almost 135 acres of trees or removing almost 100 cars from the road.

In 2002, the Miramar Operations Station Administration Building became the City's second "green building". The administration building is the City of San Diego's most energy efficient municipal facility. Built in 1981, the 18,000 square-foot administration building is the operation station's nerve center. In October 2002, the administration building began operating on a 61.5 kW AC "net zero" photovoltaic (PV) array. The array is capable of generating about 91,950 kWh annually. The 468 solar panels form the roofs of two carports at the administration building's parking lot.

The City will save $16,551 annually in energy expenses that would have been used to cover energy costs at this building. To fund the PV installation the City received $263,925 from the California Energy Commission (CEC). The total cost of the project is $681,415, but with the additional funding the total cost to the City is $417,490. Current "building envelope" energy'saving upgrades include a heat-reflecting "cool roof" and heat-reducing window awnings, a high-efficiency air conditioning system with programmable thermostats, and energy-saving T8 fluorescent lighting fixtures that feature daylight and occupancy sensors, and efficient electronic ballasts. The building is 38 percent more energy efficient due to the building envelope energy reductions. More than 80,000 kWh is saved annually and about 45 tons of carbon dioxide and other greenhouse gases are diverted from the atmosphere. Annual cost savings are more than $14,000. Mayor Murphy has continued to "push the envelope" to advance green buildings. In the newest version of Council Policy 900-14 Sustainable Buildings Expedite Program, adopted in 2003, the Mayor and City Council state that all new buildings and retrofits over 5000 square feet with have to meet the USGBC's LEED criteria at the Silver level. LEED includes all the aspects of sustainable building discussed here: energy and resource efficiency, water conservation, waste reduction, use of renewable energy, etc. and awards points for each design element on a 78-point scale. Silver level buildings must score at least 39 points, which may not sound like much, but keep in mind that the average building would probably score between 10 and 15.

It's easy to make a difference when you-re willing to try new things. Through the City's use of sustainable building technologies, San Diego taxpayers save more than $250,000 in annual costs, and keep approximately 600 tons of greenhouse gases and pollutants out of the air By making the commitment to sustainable buildings like Ridgehaven, Mayor Dick Murphy is leading San Diego toward a future that we can all be proud of. For more information, contact Tom Arnold, Environmental Specialist at: or John Helminski, Senior Energy Project Engineer at