Headquarters Office Renovation Team
San Francisco Bay National Wildlife Refuge Complex, Fish and Wildlife Service, Fremont, California
Point of Contact
Jim Burby, PE
The renovated Headquarters Office at the San Francisco Bay National Wildlife Refuge (NWR) Complex was transformed into a model of sustainability, consuming 52% less energy than the previous headquarters office building and saving 104 megawatt-hours (MWh) of energy annually, offsetting 72 metric tons (MT) of carbon dioxide equivalent (CO2e). Passive solar energy technologies include light-bronze double-glazed low-e windows, doors with thermal-break frames, expansive spray foam wall and ceiling insulation, and daylighting. Energy-efficient lighting, occupancy sensors, and ENERGY STAR appliances save electricity, and a solar-thermal collector with an interior heat reservoir provides the domestic hot water. Low-flow plumbing saves 5,000 gallons per year. Salvaged cedar boards, heavy-timber beams, and useable portions of the original electrical system were incorporated into the building renovation. About 75% of construction waste was recycled. Over 60,000 visitors enjoy the benefits of this green building each year.
The San Francisco Bay NWR Complex (pictured below) is comprised of 50,000 acres on seven central coastal California refuges devoted to preserving migratory birds, endangered species, over 400 species of wildlife, and their habitats. Habitats include sand dunes, salt marshes, rocky offshore islands, and wetlands that are home to a large variety of resident and migratory waterfowl and other wildlife species. Many species managed by the Complex are endangered, threatened or declining species, several of which survive only on or near refuge lands.
The office itself is located near the crest of several-hundred foot tall, relatively windy, bluff-overlooking, tidal marshlands. The 1970-vintage design of the 9,022 square-foot building emphasizes numerous windows with sweeping vistas. Renovation focused on weatherizing and insulating the heavy timber wood frame building in addition to otherwise conserving energy with passive solar energy technologies, as follows:
- Replaced all of the windows with new double-glazed, low-e windows to reduce winter heat loss, and repaired and replaced existing windows with thermally-broken frames, which are not normal for this locale (i.e., conventional windows and doors).
- Specified a light-bronze tint to reduce heat gain 25% while reducing glare for all exterior glass panes. The selected windows reduce HVAC run time by as much as 20% compared to conventional thermal-pane windows with clear glazing.
- Added a few new windows to increase daylighting of interior spaces.
- Applied spray-applied expansive-foam insulation comprehensively in walls and vaulted ceilings to seal and thermally insulate the building envelope.
- Installed high-efficiency fluorescent T-8 lighting with electronic ballasts, LEDs controlled by motion sensors and photocell controls, and LED Exit signs.
- Installed new ENERGY STAR appliances in the break room kitchenette.
- Replaced the existing propane-fired boiler with a new 6-ton ductless air-source heat pump (ASHP) Heating, Ventilation, and Air Conditioning system that includes heat recovery of the exhaust air, and does not require supplemental heat. The ASHP is 3.1 times more efficient than electric resistance heat. Renewable energy is provided indirectly by adding a 56-square foot, closed-loop, fixed-tilt, flat-plate solar-thermal collector (pictured below) that with an interior heat reservoir that provides 100% of the domestic hot water and eliminates 150-gallons of propane annually. The sustainable building retrofit conserved both indoor and outdoor water.
- Indoors, all plumbing fixtures such as sinks, lavatories, urinals, water closets, and toilets were replaced with EPA low-flow WaterSense fixtures. Outdoors, landscaping featured native plants adapted to the mesic-xeric cycle of Mediterranean climates that are not watered. Domestic water is metered. The facility will save 5,000 gallons of water annually with these devices.
- Construction related wood, metals, cardboard, and glass were separated fully and recycled, diverting about 75% of the construction waste from landfills. Cedar boards and heavy timber beams were salvaged and incorporated into the building renovation, as were useable portions of the original electrical system. The renovation features recycling bins incorporated seamlessly into the cabinetry, enabling the office staff to routinely sort plastic, glass, metal, and paper products for transport to the recycling centers. An estimated 400 pounds of waste is avoided annually.
Results and Achievements
The $2.5 million office renovation resulted in energy efficiency much greater than 30% from ASHRAE 90.1-2007 standards, or 52% less energy. The project reduced electricity by 28 MWH, and entirely eliminated 2,700 gallons of propane, for a total of 353.52 MMBTUs, which is equivalent to 104 MWH in energy savings. Assuming a 20-year life, the estimated lifecycle energy savings is 7,070 MMBTUs. Energy savings in 2010 includes the reduction in electricity for $23,900 and the entire elimination of propane for $10,300, for a total actual energy cost savings of $34,200. (The fuel cost saved in 2010 is reported as energy savings.) Of the total energy reduction, 62.4 MWH is attributed to indirect renewable energy offsets: solar-thermal domestic hot water, passive solar glazing, and ductless air-source HVAC. Assuming a 20-year life, the estimated lifecycle renewable energy production would be 1,248 MWH. The building renovation remarkably reduced greenhouse gas emissions, indirectly offsetting a total of approximately 72 metric tons of greenhouse gases annually.
Numerous non-energy benefits are seen throughout the newly renovated facility. For example, the compactness of the new ductless HVAC system freed 500-square feet of former mechanical room space that was renovated into mail handling and computer rooms. The energy reductions achieved avoided the need to up-size the relatively small amperage building electrical service, saving about $50,000 for features of higher value. A secondary benefit of the spray-applied foam thermal insulation was also used to sound-insulate the interior walls. Excellent sustainable materials management was attained via salvage, recycling, and selection of green building materials. Basically, the renovation was accomplished within the original building footprint without disturbance to the existing landscaping. The roofing meets the ENERGY STAR Cool Roof reflectivity criteria. Materials such as paint, carpet, vinyl, waste baskets, and modular furnishings are of high-recycled content (and low VOCs to protect indoor air quality). Interior doors are made of an agricultural straw-based product. Finally, metal components for wall corner guards and mini-blinds were used instead of petroleum-based plastics.
The renovated office building is equivalent to a Leadership in Energy and Environmental Design (LEED) Certified rating. The Service is considering applying for a LEED EB rating, since it now complies with the Guiding Principles for New Construction. Suppliers had to be convinced that the Service was serious about the products specified. The Service proactively far exceeded the requirement of Section 523 of EISA 2007 that 30% of the hot water demand of a major building renovation shall be met through installation and use of solar hot water heaters—this project met 100% of the demand.
This project is a unique application of innovative sustainability. An integrated team guided the collaborative design process for building renovation. The energy features are seamless, relatively simple, fully transferable, and relatively easy to operate and maintain at low cost. The team consisted of the Service, building users and management, professional design consultants, the general construction contractor, representatives of key specialty construction trades, and equipment manufacturers who communicated on a regular basis throughout the design, construction, and commissioning processes. Without increasing the building footprint, all performance goals were met throughout the design of the building. Commissioning and energy monitoring has been ongoing since the building became operational.
This highly successful project demonstrated practical, readily transferable, easy-to-implement, energy efficient construction techniques. It provides impetus for requesting funding for similar projects. The knowledge and awareness of the energy efficient design and construction from this project is being transferred to projects in other Service Regions. In addition, this project practically demonstrates a way to maximize key building renovation design elements necessary towards helping the Service achieve its Climate Change goal of carbon neutrality by 2020. More than 60,000 visitors annually learn about sustainability, energy conservation, and the environmental benefits achieved by this recent office renovation through showcase exhibits.