505 Brannan (Pinterest HQ)

Completed in 2017, the new headquarters for San Francisco-based Pinterest are designed with the possibility of adding a tower in the future. This means that the building must be strong enough to support the future 165-foot tall tower addition. Certified LEED Platinum, the 150,000-square-foot building includes flexible work areas for Pinterest employees, a public lobby and cafe and onsite cafeteria. The building is located down the street from SF's main Caltrain station, and next to one of the new stops for the Central Subway, which is set to be complete in 2019.