An ASHRAE LII Energy Audit was conducted on the former AT&T Headquarters also known as the Bishop Ranch BR-2600 Camino Ramon building which is located in San Ramon California. Built in 1983, this building is part of a larger planned development known as Bishop Ranch that is a Class-A building that is built in four separate wings within a 100-acre park-like setting with over 1,800,000 square-foot of office space. The owner is San Ramon-based Sunset Development Company and New York City-based MetLife. With this huge complex, the AT&T regional office complex is located here and includes other Bishop Ranch tenants which includes GE Digital, Chevron, SAP, Accela, and Five9. The San Ramon area now has the second-largest concentration of computer-engineering employees in the Bay Area, behind only Silicon Valley. The 2600 Camino Ramon building-campus has undergone extensive mechanical upgrades and tenant improvement over the last five years which has provided more efficient and sustainable operations.