Concrete key to San Mateo County's new net-zero HQ

REDWOOD CITY – San Mateo County is putting the environment first in construction of a new 330,000-square-foot office in downtown Redwood City to house county services.

Known as COB3, the five-story building under construction at Marshall Street and Middlefield Road will target LEED Gold certification from the U.S. Green Building Council and is planned to operate at net-zero energy.

Key to achieving the sustainability criteria for the LEED certification are the building’s water and energy consumption as well as materials used in construction, which includes environmentally friendly concrete from Graniterock.

Graniterock has supplied more than 3,200 yards of concrete produced with supplemental cementitious materials, saving approximately 555 tons of cement, for construction of the building foundation.

“This is an important project for San Mateo County that perfectly aligned with Graniterock’s ability to deliver the mix design necessary to help the building achieve LEED Gold,” Max Morgan of Graniterock said.

COB3 will improve public experience by offering a one-stop-shop for county services, create a vibrant campus with a strong civic identity that well represents the county seat and consolidate office space from multiple locations of leased/aged facilities for various departments to enhance operational efficiency.

The $500 million capital investment includes the office building and seven-story parking structure with 1,200 parking spots.