Attachment A – LEED and LBC The City of Santa Monica is an internationally recognized a leader in sustainable city planning. In 1994, it was one of the first cities in the world to publish a Sustainable City Plan. The City continues to pursue long-term environmental goals outlined in its Climate Action Plan. Current City codes mandate enough sustainable features to almost guarantee a minimum LEED Gold rating for new building projects. LEED Platinum, the highest LEED standard, is becoming increasingly common. The Pico Library, completed in 2014, is on track to achieve LEED Platinum certification.
LEED Certification In 1993, LEED, Leadership in Energy and Environmental Design (LEED), was developed as a program of the U.S. Green Building Council. LEED certification has been recognized across the globe as the premier mark of achievement in green building. Buildings are rated LEED Certified, Silver, Gold and Platinum based on increasingly rigorous measurements. For more information on LEED, see http://www.usgbc.org/leed.
The Living Building Challenge In 2006, an even more rigorous international rating standard for sustainability, the Living Building Challenge, was developed by the International Living Future Institute (ILFI). The Living Building Challenge is a philosophy, advocacy tool, and certification program that promotes the most advanced measurement of sustainability in the built environment. Similar to LEED, the LBC offers three levels of recognition: Living Building Certification, Petal Recognition or Net Zero Energy Building Certification, the most challenging level is full Living Building Certification. A full Living Building Certified (LBC) project achieves net-zero energy, net-zero water and contains no cancer-causing chemicals. Since 2006, only 5 projects in the world have met the standard, each of which was two-stories or less and developed by a foundation or private school. LBC differs from LEED in that it is performance based. A building project seeking LBC certification is monitored during the operational phase to determine if LBC certification is warranted whereas building performance is not a factor after a LEED rating is achieved. During the design phase of an LBC building, substantial attention is paid to how the building will be operated and occupied. A conservative design approach is used so that the designed building will produce at least as much energy and water than it consumes over the course of a year. A sixth building built to LBC standards and expected to achieve LBC certification in 2015 is the Bullitt Center, a six story, 50,000 commercial office building in Seattle, Washington. The building is occupied and currently in the operational monitoring / commissioning stage. Because the Bullitt Center is similar in size and use to the proposed City Services Building, it was studied by the project team in the Feasibility Analysis as a benchmark and aspirational model facility. More information regarding the Living Building Challenge can be found at http://living- future.org/lbc/certification. More information regarding the Bullitt Center can be found at http://ww.bullittcenter.org/.
Sustainability Approach As part of the feasibility analysis, the City Services Building was registered with the ILFI for the Living Building Challenge (LBC) to explore the impact and applicability of LBC, Petal or Net Zero certification. The project team, driven by the City’s commitment to sustainability, conducted the feasibility analysis to maximize sustainable design, construction and operation of the proposed facility within funding constraints. The project team utilized an integrated design process to identify available technical opportunities for sustainable solutions. Baseline energy and water budgets for a proposed building on this site were established and solutions were identified to provide enough energy and water to achieve Net Zero Energy and Net Zero Water Certification. Energy or water budgets are calculations of energy or water requirements necessary to serve the needs of building occupants. Budgets are designed to be both functional and conservative in their measurement of natural resources. Early-stage energy modeling simulations, utilizing the industry’s most advanced software tools, were employed to maximize energy efficiency opportunities using quantifiable data.
The feasibility analysis demonstrated that the proposed City Services Building in this location is technically able to achieve full LBC with both a Net Zero Water (NZE) and Net Zero Energy (NZW) status.
Net Zero Energy (NZE) A NZE building must create at least as much energy as it consumes. By definition a NZE building should have zero or near zero energy utility costs. A number of design variables including local climate, building size, location and orientation relative to daily and seasonal position of the sun, insulation requirements, daylighting, window to wall ratio, and overhang depth must be studied and understood to determine if NZE is feasible. Additionally, the use of natural ventilation, daylighting, high efficiency windows, heating, cooling, lighting equipment and office equipment must be studied and analyzed.
Energy model simulations help predict building performance prior to construction. The first step in an energy model is the creation of an energy budget. A baseline energy use study calculates the energy needed by building occupants based on the best data predictions available at the time (including occupancy numbers, thermal comfort levels, lighting and daylighting, equipment plug load requirements). Building power must be generated on-site and can be provided by a combination of renewable energy sources including, but not limited to: solar photovoltaic panels (PV panels), wind, solar thermal and geothermal. The proposed generated power must be equal to or greater than the annual energy budget in order to achieve Net Zero Energy.
During the City Services Building Feasibility Analysis the team identified that solar photovoltaic panels (PV panels) would be the most effective power generation source on the proposed site. Important elements of the proposed NZE strategy for the City Services Building include energy savings through the use of:
Building Envelope – use of high performance glazing and shading devices to control solar heat gain. Daylighting – strategic placement of windows and project spaces and the use of daylighting sensors and automated shades to provide natural lighting levels needed for interiors while controlling glare. Natural ventilation – reduce dependency on HVAC systems through natural ventilation. Modern designs can incorporate natural ventilation as a systematic function to manage building thermal comfort and healthy air. A building ‘weather station’ monitors weather conditions and automatically operates high efficiency windows based on temperature and pressure differential between the building and outside environment. Mechanical cooling and heating are utilized only when natural ventilation is unavailable or not suitable. In climates like Santa Monica, natural ventilation can meet all of a building’s heating and cooling needs for most of the year. Occupants would need to take an active role in order for the proposed building to achieve NZE by responding to the seasons through the use of layered clothing and adjusting clothing levels to maintain thermal comfort. Energy efficiency – all equipment in the building must be industry rated as energy efficient, which will reduce the energy load from plugged-in appliances.
Net Zero Water (NZW) NZW recognizes buildings that capture and harvest all water to achieve water independence from municipal sources. This achievement is sometimes referred to as ‘closing the loop’ on water usage.
A building water budget is calculated by determining the number of building occupants and visitors and calculating a total of their daily water use. Once the budget is established, design opportunities are evaluated to determine whether a proposed structure can be designed and constructed to achieve NZW. One affordable water conservation method with a low energy footprint is the use of composting toilets. It is estimated compost toilets would reduce the CSB water usage by over 55%.
During the City Services Building Feasibility Analysis, the design team evaluated multiple technologies in order to achieve NZW. These included the use of a living machine (an ecological wastewater treatment designed to mimic the cleansing functions of wetlands), sewer mining (capturing water from the sewer and processing it on site) and dew harvesting (capturing moisture from the air on site) none of which are recommended because of the size of the building site or the low water yield.
A 50,000 gross square foot commercial office building such as the proposed City Services Building would have a water budget of approximately 34,000 gallons of water a month. The use of composting toilets would reduce water use in the building by 19,000 gallons per month. The remaining required 15,000 gallons a month would then be able to be supplied using the following combination of recommended strategies: Rain/Stormwater harvest with on-site treatment. Graywater and process water capture and reuse for irrigation. Groundwater well with on-site reverse osmosis (RO) to be used in extreme drought conditions.