Atherton Library

2023 All-Electric Leader
outstanding commercial project

Location: Atherton

Building type: Library

Status: Completed

Size: 9,601 gross square feet

Completion date: June 2022

Energy Use Intensity: 28

Owner: Town of Atherton and San Mateo County Libraries

Contact: Pauline Souza,


Eager to restore its historic charm and preserve natural space, the Town of Atherton united to upgrade their aging civic center, including constructing a new 9,601 sq. ft. library, nearly doubling its previous size. The result is a Net Zero Energy-ready, all-electric, healthy building targeting LEED Gold certification. 

In alignment with town, state and federal carbon reduction goals, the library included passive design strategies and was built without any methane/natural gas, making the entire facility 100% electric, including space and water heating.

The design maximizes daylighting and natural ventilation, makes use of outdoor spaces, and integrates low-carbon materials. Thermally efficient rammed earth walls blend the building with the environs while maintaining indoor temperatures.

The displacement HVAC system distributes fresh, conditioned air into zones, lessening energy demand for unoccupied spaces while pushing out stale air. Coupled with air source heat pumps, cooling and heating loads are reduced, paving the way for Zero Net Energy (ZNE).

The 100-kW PV rooftop array will supply 100% of the structure's energy, so that all of the project's energy needs will be offset through on-site renewables.

Passive Design Strategies:

  • Orientation
  • Shading
  • Landscaping
  • Daylighting
  • Skylights, clerestories
  • Thermal mass
  • Envelope insulation
  • Glazing: Low E Insulated glass

Special Features:

  • Heat pump water heater
  • Onsite renewable energy: solar PV
  • Air source heat pump heating and cooling
  • Energy Star appliances
  • Other: LED lighting with dimming controls and plug load controls

Project Team:

Architect: WRNS Studio
Mechanical, plumbing, energy consultant and commissioning agent: Interface Engineering
Electrical engineer: Integral Group
S. J. Amoroso Construction
Project manager: Marty Hanneman, Interwest