Phil Williams, Webcor vice president
Phil Williams, Webcor vice president

When San Francisco-based Webcor Builders dug deeper into the roots of its carbon footprint two years ago, it found that a remarkable 99.6% of its building and operational greenhouse gas emissions was embedded in the products and materials it purchased from its supply chain partners.

Working upstream with clients, architects, and engineers and downstream with its suppliers, California’s largest general contractor sought to address the issue with better building design that required fewer materials and a less-impactful mix of specifications.

Those efforts are exemplified in the San Francisco Public Utilities building, a 15-story, LEED-Platinum project completed earlier this year. The structure features innovative post-tension poured concrete slabs and shear walls that not only better manage seismic forces but also reduced the carbon footprint of the overall structure by 40%, or 7 million tons of CO2 emissions ... and reduced costs by $10 million.

“Our research found that carbon emissions from the supply chain were most embedded in the structure, skin, mechanicals, and interior finishes of a building, in that order,” says Webcor vice president Phil Williams. “Good design is the first step, but so is the right mix of products.”

Gathering consistent and comprehensive data from the supply chain, however, is not easy. Carbon reporting and Environmental Product Declarations are in their infancy, especially among building products, yet are critical to accelerating mainstream sustainable construction. “It’s a critical piece of information if we hope to move toward net-zero energy and carbon-neutral buildings,” says Williams.

Webcor reported its supply chain carbon footprint findings to the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) in an effort to establish consistent national and global standards for carbon reporting and help accelerate the practice. The builder also has since required greenhouse gas emissions data in contract bids from its suppliers as a matter of policy on every job.

This year, the builder of nearly 9 million square feet of multifamily and commercial space is working with Climate Earth to add water intensity and toxicity measures to its internal and supply chain carbon reporting databases to broaden the scope. “Both are potentially huge issues and require establishing standards beyond code minimum,” says Williams, both internally and through WRI, WBCSD, and other agencies.