SAN FRANCISCO—Developer Kilroy Realty Corp. broke ground this week on San Francisco’s first new LEED Platinum tower, 350 Mission Street. The 450,000-sq.-ft. office tower is already 100 percent pre-leased to salesforce.com.

“The construction of 350 Mission Street affirms the investor confidence in our City, and I am pleased to partner with salesforce.com and Kilroy Realty on this exciting venture to help deliver on a vision for the Transbay district where people can live, work and play sustainably with rich access to regional transportation,” said Mayor Lee at the groundbreaking ceremony this week.

The project, slated to open in the beginning part of 2015, works to incorporate state-of-the-art sustainability practices such as using recycled materials and energy efficiency technology. The design calls for open floor plates, high ceilings, full height glass, as well as energy-efficient operating systems.

“It is very rare to have an opportunity to develop from scratch a cutting edge work environment in one of the nation’s most forward-looking cities for one of the most innovative companies in the world,” said KRC’s CEO John Kilroy. “We view this project as an important demonstration of what imaginative partners, focused on sustainable development, can accomplish.”