Sonoma Clean Power Headquarters Renovation 

Company:
EHDD Architecture
Pier 1, Bay 2 The Embarcadero
San Francisco, California 94111 
(415) 285-9193
https://ehdd.com/
Contact:
Brad Jacobson
Business Phone: (415) 214-7276

Project Location: Santa Rosa, CA 
Completion Date: 01/01/2021
Owner: Sonoma Clean Power

Architects Involved:
N/A

Additional Team:
Midstate Construction, General Contractor, Petaluma, CA
Sixth Dimension, Construction Manager, Oakland, CA
GUTTMANN & BLAEVOET INC, MEP (Engineer of Record), Santa Rosa, CA
POINT ENERGY INNOVATIONS , MEP (Schematic Design), San Francisco, CA
Reed Gilliland, Landscape Architecture, Petaluma, CA
ZFA STRUCTURAL ENGINEERS, Structural Engineering, Santa Rosa, CA
BKF ENGINEERS, Civil Engineering, Santa Rosa, CA
RGD ACOUSTICS, INC., Acoustics and Audio-Visual, San Rafael, CA
INTEGRATED DESIGN LAB, Daylighting, Seattle, WA
New Buildings Institute, Grid Optimal Advisor, Seattle, WA
VAN DEUSEN & ASSOCIATES, Elevators, San Francisco, CA
TBD CONSULTANTS, Cost Consulting, Los Altos, CA

Project Description

Sonoma Clean Power (SCP) is the public electricity provider for California’s Sonoma and Mendocino counties, aiming to provide 100% renewable electricity to customers. SCP chose to purchase a dated commercial office building in downtown Santa Rosa and transform it into a high-performance headquarters and zero carbon demonstration project. Their goal was to minimize their climate impacts as an organization through addressing “whole life” emissions, including both operational and embodied carbon.  

Sonoma Clean Power leadership wanted their new company headquarters to demonstrate how outdated building stock could be transformed into high-performance buildings with minimum cost and carbon impact. With surgical precision, the building was retrofitted for peak energy performance and minimal embodied carbon: the design utilized 95% wood construction, increased daylighting for a reduced energy load, and added a demonstration parking lot with electric charging at each stall, fed by an on-site PV system and battery.  

The design team’s real innovation, however, lies beyond these modifications, in the creation of the first-ever “grid optimal” building:   

  • This is the first-ever pilot project for the Grid Optimal® Buildings Initiative, a New Buildings Institute and U.S. Green Building Council innovation program.  
  • As the first grid-responsive building, SCP headquarters monitors the demand on the public grid and adjusts to draw from its onsite battery system OR return stored energy to the public grid.  
  • This reduces the state’s reliance on carbon intensive energy plants and promotes fully renewable electricity supply.  
  • The building serves as the community’s emergency command center through the activation of the microgrid and operation of the battery and PV system independently of the public grid. 

The 15,330-sf, two-story, wood-framed building today serves as SCP’s high-performance workplace and headquarters. 

Design Challenge

Transforming an Outdated Building into a High-Performance Workplace and Customer Center  This project enhances SCP’s image within downtown Santa Rosa by creating a headquarters that elevates the context without seeming extravagant, respecting the financial contributions of ratepayers. The reoriented entrance experience is framed by a unifying wood screen at the second level, which shades a staff terrace while smoothing out a previously jarring façade composition. This simple, cost-effective design approach demonstrates that existing buildings can be transformed into high-performance structures and highly functional workplaces within a modest budget.   The design addressed SCP’s multifunctional and complex program needs. The design elegantly zones customer and employee pathways. This zoning maintains security and privacy for staff and establishes a welcoming atmosphere for customer-facing programs, board meetings, and community gatherings in a multi-purpose room off the lobby. The multi-purpose space can be readily converted into a command center during emergencies through the activation of the microgrid and operation of the battery and PV system independently of the public grid.   Abundant, well-balanced daylight is provided through enlarged north-facing windows and diffuse sky lighting. An existing dropped acoustic ceiling concealed an existing trussed, gabled roof. Our design opened this volume with acoustic drywall and lights integrated into the truss bottom chords, creating grandeur out of existing conditions.   A Grip-Optimal, Zero-Carbon Building  Our client asked for a “Zero Carbon” building that “goes beyond California’s current ‘net zero’ concept and ensures that all energy is carbon free.” The design team proposed a smart, grid-responsive building that adjusts energy flows based on the real-time carbon intensity of grid electricity. The first step was retrofitting the existing building to current energy efficiency standards through simple, low-cost systems befitting a customer-focused organization. Strategies and features include: 
  • All electric systems: Removal of all gas infrastructure; Full electrification of building heating, hot water, and induction cooking  
  • Upgraded envelope: All new windows, insulation, and air sealing 
  • Exceptional daylighting: Skylighting, enlarged north windows, and bright surface characteristics  
  • Enhanced comfort: “Smart” controllable thermafusers, destratification fans for thermal comfort  
With energy-efficiency as a base, the building’s flexible microgrid relies on an hourly signal of grid emissions to adjust its energy source, pulling from either the external power grid or its on-site 220kWh battery system. The building’s 23 electric car chargers, building lights, HVAC, and water heating only draw energy from the external grid when plenty of clean power is available. This allows the microgrid to store and utilize renewable energy, and even supply power back onto the external grid at times when other buildings need it.   The battery system typically charges around noon when there is an abundance of solar power. During the evening, the building then uses that energy or returns it to the grid to reduce the state’s reliance on gas-polluting power plants. The microgrid also provides resilience, allowing portions of the building to operate when the grid is down due to power outages, which is critical to maintain services to customers. This is especially relevant based on Sonoma County’s increasing susceptibility to wildfires. 

Physical Context

SCP’s new headquarters is one-quarter mile from the old town square of Santa Rosa, CA. The organization’s decision to purchase and transform an underperforming, non-descript building represents a commitment to the revitalization of downtown Santa Rosa. The location takes advantage of the tree-filled, amenity-rich, walkable downtown neighborhood with restaurants and cafes nearby, and close adjacency to SCP’s new customer demonstration center. The site strategy combined two lots, allowing us to reorient the building toward a welcoming entry courtyard and a demonstration parking lot with electric charging at each stall, fed by on-site PV and battery.   A key feature of the site design was the preservation of several heritage trees, including two 300-year-old oak trees, that now help cool the building during the summer.   Our design team carefully coordinated underground electrical work to protect the tree’s root structure. Additionally, the design’s understated facade and natural material palette foregrounds the trees and Santa Rosa’s local ecology. A new staff terrace off the breakroom provides a place for socializing and respite amongst the tree canopy's shade.  Santa Rosa is rapidly warming and perennially at risk of wildfire and power outages, both in the city and in the utility district. Water scarcity is ever-present as water supplies from nearby Lake Mendocino and Lake Sonoma are subject to fluctuating annual rainfall levels. By creating a resilient building that can operate independently from the external grid and serve as a command center during emergencies, this design empowers SCP to better serve its community.