2024 USGBC-CA Green Building Awards
Merit in Energy/ Operation Carbon
The project includes many different sustainability features such as lower embodied carbon (reusing a building saves 55-85% of the upfront carbon), reduced energy and water consumption (indoor water use reduction of 41%), enhanced lighting performance (savings of around 50%), optimized MEP systems, and other features contributing to the project's LEED Gold certification. With access to quality transit and bike facilities provided onsite, the project’s parking footprint and related emissions are reduced. The project team utilized collaborative and integrative processes to take a holistic approach to the sustainability effort and provide a healthy and comfortable environment in which tenants can work and thrive.
In addition to the building reuse, the project underwent a Life Cycle Assessment (LCA) to account for the amount of embodied carbon the interior renovation contributed to its overall impact. Collecting Environmental Product Declarations (EPDs) and conducting LCAs allows for transparency in how much each different product is emitting in greenhouse gases. By using an existing building, the project’s embodied carbon is 206,877.74 kg CO2e or ~19 kg CO2e/ m2. The average newly constructed office building has an embodied carbon of 230-320 kg CO2e/ m2. Through building reuse and sustainable materials, the project was able to achieve a large carbon reduction from benchmark values.
The mechanical, electrical, and plumbing systems have been optimized to reduce consumption. Through LEED v4 energy modeling it was found that the project’s energy use is projected to be 21% lower than the ASHRAE baseline. The project had an energy cost savings of 19%, which for interior projects yields 22 LEED points for the Optimized Energy Performance credit. There are savings in heating, cooling, fans, and interior lighting. In order to achieve these savings, the mechanical systems have been optimized. The project uses the existing water-cooled chiller and tower, which are efficient systems, in addition to new high-performance heat pumps. Additionally, the office’s fans and pumps are equipped with variable frequency drives (VFD). This allows for the project to control the amount of air and water at variable levels in order to eliminate unnecessary consumption. Without having these VFDs the project’s system would be supplying air and water at a consistent rate, even if less is needed at a given point. Providing this adaptability greatly improves the efficiency of the project. Through all of these features the project achieves an EUI of 30 kBtu/ sqft.
A large amount of the energy savings is due to the LED lighting fixtures throughout the project, which show savings of around 50%. To further reduce the need for artificial lighting, the team ensured there was adequate daylighting in the project through daylight analysis. The simulation found that the project’s regularly occupied spaces achieve an sDA of 50%, earning an additional LEED point in the Daylight Availability credit. Plentiful daylight along with daylight sensors allow for a reduction of artificial lighting when there is enough natural lighting. This reduces the energy load in two ways: through using less interior lighting and by reducing the heating load for the space. Artificial lighting can give off heat, so using less lighting can reduce the need for cooling.