Thornton Tomasetti’s 15,000-square-foot office at 650 California St. was awarded Platinum certification under the LEED ID+C: Commercial Interiors v4 rating system earlier this month. Photos Benjamin Grimes
Thornton Tomasetti’s leadership and Sustainability team drove the creation of an environment in our San Francisco office that is not only aesthetically stunning and functionally adaptable, but also very green. So green, in fact, that our 15,000-square-foot space at 650 California St. has earned the first Platinum rating in the United States under version 4 of the LEED for Commercial Interiors green building rating system.
“Leadership in Energy and Environmental Design (LEED) certification was an important aspect of the San Francisco office build out,” Managing Principal John Abruzzo said. “In addition to the firm’s commitment to sustainability, we also wanted to provide employees with a healthy and comfortable work environment that fosters collaboration and creativity. We decided to pursue LEED Platinum v4 because it not only supported our objectives, it provided us with a learning opportunity on the intricacies of the new rating system. We are excited that we were able to achieve this goal and to use this space as a laboratory of sorts for indoor environment analysis and design.”
From the early planning stages of the project, the Sustainability team was passionate about participating in the LEED version 4 Beta program in order to contribute to the vetting of new rating system requirements and strategies. Version 4 is the most stringent green building rating system offered by the U.S. Green Building Council and the new benchmark for green design and construction. Through involvement in this v4 program and achieving Platinum level certification, Thornton Tomasetti’s green building professionals have further established their expertise in certifying sustainable building projects.
Involved in the project were Senior Vice President Lynn Simon, Vice President Joel Stout, Senior Project Director Abena Darden, Project Consultant Maggie Smith, Senior Associate Vamshi Gooje, Associate Colin Schless and Vice President Mike Dowdall. Our project partners included architects Gensler, building owner Tishman Speyer, general contractor BCCI and mechanical and electrical design engineers Guttmann & Blaevoet.
To achieve a Platinum rating, the San Francisco office earned 80 points out of a possible 110. Areas of building design and construction where we strived for a Platinum rating include: energy performance, advanced metering, enhanced commissioning, daylighting analysis/views and interior materials and furnishings.
Here are a few highlights from that push for Platinum.
Our Sustainability practice and building analytics team provided feedback to the USGBC about how small tenant improvement projects are at a disadvantage because of the baseline requirements in the simulation option of the energy performance credit. Counter to prior versions of the LEED rating system, in CI v4 the envelope baseline is set to ASHRAE 90.1 – 2010 instead of the existing envelope. Tenants that lease space in brand new buildings are not impacted much, but small tenants taking space in buildings constructed many decades ago are penalized by the older building stock. This project type doesn’t have the budget or, in most cases, the opportunity or ability to modify the building envelope. A historic building envelope, for instance, may not be allowed to be modified. In major renovation projects that register under LEED v4 for New Construction, the baseline is set as the existing envelope prior to renovation commencing. Our San Francisco office is located in an iconic 1964 building, and the envelope cannot be made equivalent to the ASHRAE 90.1 – 2010 baseline. Therefore, our team focused on every other possible opportunity to improve energy performance. Strategies included window film on the south and west sides to improve the performance of the existing windows by reducing the solar gains, LED lighting fixtures with daylighting controls that reduced lighting energy use by 55 percent from the baseline requirements and plug load management using exceptional calculation to take advantage of plug load savings that are typically not realized in LEED projects. Despite the challenges, our team was able to achieve 21 of 25 points available in the Optimize Energy Performance credit and an additional point for regional priority, which credits projects for focusing on local environmental issues.
The space has ample daylighting with views of Chinatown and Fisherman’s Wharf.
Incorporating electrical end-use metering into tenant fit-out scopes of work is not very difficult. However, space heating and cooling energy coming from the base-building central plant is much trickier, especially in a 50-year-old building. In addition to temperature and flow meters, calculations are required in order to arrive at the portion of central plant energy that is attributable to the tenant space demand. Additionally, central plant data is the property of the landlord, so an agreement about access to building management system (BMS) data is important.
In LEED v4, enhanced commissioning (Cx) has stepped up significantly to include options for enclosure Cx (BECx) and monitoring-based Cx. Although Thornton Tomasetti provides BECx services, that option is not included in the Commercial Interiors form of the v4 rating system, so we followed the monitoring-based option. Our approach utilizes both BMS signals collected through the HVAC direct digital controls (DDC) of as well as tenant-managed electrical metering and monthly data analysis.
Most of the materials and furniture used in the space have Health Product Declarations and Environmental Project Declarations.
Daylighting and Views
LEED v4 requirements for demonstrating compliance in daylighting are more complex and difficult to achieve. This is partially due to the requirement for analysis on two dates per year with a 5-month gap in between. So in our case both a spring and fall analysis of the daylighting levels had to be within the required range. Using both computer simulations from our building analytics team and actual daylight meter readings taken in the completed spaces, it was determined that our floor plate was slightly too deep for demonstrating compliance. However, it was very close to the target, and during most of the year we actually have the desired amount of daylight throughout our space. The project had little difficulty in demonstrating compliance with the increased requirements for providing quality views for employees.
Interior materials and furnishings
Thornton Tomasetti’s Sustainability team worked with Gensler and BCCI to identify the most building materials and products possible that could meet the transparency requirements of having an Environmental Product Declaration. At the time that the project began design, not many manufacturers were quite ready with their declarations. Forward-thinking companies knew it was coming in LEEDv4, but the Beta program was arriving ahead of many of declarations being published. Although it was quite challenging to both material selection and to the project budget, enough materials were acquired in time for the LEED submittal. Additionally, LEED points were earned for material ingredient reporting and leadership practices in sourcing of raw materials. The office was also designed for convenient separation of occupant waste into three streams: landfill waste, recyclable materials and composting.
The San Francisco office marks Thornton Tomasetti’s sixth LEED certification in five of our offices. The Kansas City, Chicago, Philadelphia and Denver offices are LEED Gold certified and an expansion project in Chicago earned a LEED Platinum rating. Two other offices are slated to receive certifications this year. The firm’s corporate sustainability policy calls for all new offices and major renovations of 4,000 square feet or more to seek LEED CI certification at the gold level or higher.
“Thornton Tomasetti’s San Francisco Office Platinum LEED certification demonstrates tremendous green building leadership,” Rick Fedrizzi, CEO and founding chair of the US Green Building Council, said. “The urgency of USGBC’s mission has challenged the industry to move faster and reach further than ever before, and this project serves as a prime example of just how much we can accomplish.”
By the Numbers
Here is the San Francisco office LEEDv4 credit achievement by rating system category:
• Integrative process (1 out of 2 possible points). We attempted both points, but didn’t have access to a non-potable water source.
• Location and Transportation (18 of 18). Achieved 100 percent of points despite not being in a LEED-Neighborhood Development location.
• Water Efficiency (6 of 12). Achieved 50 percent of points (35 percent better than code), limited by base-building fixture standards. Funded the upgrading of plumbing fixtures to greatest extent allowable in the building.
• Energy and Atmosphere (30 of 38). Achieved 79 percent of points despite the handicap of 1964 building envelope being compared to an ASHRAE 90.1-2010 compliant (new building) envelope.
• Materials and Resources (6 of 13). Achieved 46 percent of points.
• Indoor Environmental Quality (9 of 17). Achieved 53 percent of points.
• Innovation and Regional Priority (10 of 10). Achieved 100 percent of points.
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