Construction has wrapped on the Larkin Street Substation addition in San Francisco, California. The net-zero energy (NZE) targeted project is designed to meet the practical needs of the utility building while enhancing the surrounding community.
The steel frame concrete structure by TEF Design is a modern addition to the existing historic 1962 substation building designed by Pacific Gas and Electric (PG&E) to supply power to the northeastern part of the city.
The constrained property and need to accommodate crane and equipment lift access prescribed the expansion’s perpendicular orientation to the existing substation. The structure features street-facing façades which integrate three types of glass fiber reinforced polymer (GFRP) panels—sloped, perforated, and ribbed—to form a surface that contradicts its materiality.
Sloped panels embedded with lighting fixtures expand across the building at night, expressing the city’s electrical power grid. The west-facing green wall, planted in a geometric pattern which echoes the faceted concrete walls, provides biophilic relief to the urban block while asserting its contribution to green values. A fine-grained metal mesh provides a transition between the existing structure and its new addition and is also used to bookend the façade.
On top, 60 kilowatt (kW) solar panel arrays offset the building’s energy consumption. Large vents at the base of the building exploit the city’s cool temperatures through natural ventilation to help eliminate the need for artificial cooling and reduce the building’s energy load by nearly 40 percent. Inside, supplemental fans, triggered only at high temperatures, help to cool the building only when needed.
The PG&E Larkin Substation addition is one of the first targeted net-zero electrical switchgear utility buildings to get a rating from the International Living Future Institute’s (ILFI) Living Building Challenge. The design team collaborated with ILFI to establish a rating system for registering the unprecedented building type.