SIZE: 25,000 SF
TYPE: Government office and archive facility
Measurement & Verification
Zero Net Energy
LEED New Construction v4 Gold
County of San Diego (Client)
Miller Hull (Architect)
C.W. Driver (General Contractor)
Latitude 33 Planning & Engineering (Civil Engineer)
Coffman Engineers (Structural Engineer)
Interface Engineering (Mechanical Engineer)
Electrical Engineer (Elen Consulting)
stok (ZNE Consultant)
Strategy & Services: The County of San Diego’s new Assessor, Recorder, and County Clerk East County Office and Archives Facility (ARCC ECO) is slated to be the first Zero Net Energy (ZNE) archive facility in the country. Led by the County’s ambitious performance targets and LEED v4 Gold certification pursuit, the project team implemented sustainable measures across the board, from energy and water conservation to waste reduction, sustainable transportation, and healthy material selection. stok was engaged by the County early in the design-build project to provide a path to ZNE performance through energy modeling, measurement and verification, and occupant training.
Project Details: The project team was faced with navigating the very technical, controlled, and energy-intensive conditions required of an archive, including a narrow range of temperature, humidity, and pollutant conditions. From the start, stok’s feasibility analysis assured the County that ZNE performance was possible, then helped the design and construction teams identify accessible practices and products to achieve it. To ensure operational performance early on, the stok team brought together all the key players in the measurement and verification process to deliver a critical, properly functioning monitoring system. Finally, stok assisted the design team with a whole-building energy model to help the project achieve ZNE in the most efficient way possible.
The project draws on a combination of energy conservation measures and on-site energy production to achieve ZNE performance. Based on energy recommendations from stok and the project team, the facility features:
• Large windows to capture daylight while a large overhanging south roof controls glare and excess heat gain
• High degree of control over lighting and plug loads through daylight sensors, LED fixtures, and occupancy sensors, which helps lower the overall impact of small loads at scale
• High-efficiency variable refrigerant flow system (VRF) to heat and cool the building
• Highly insulated envelope
• 253,200 kWh/year photovoltaic array mounted on building roof and parking lot canopy to offset remaining energy demand, with a 10% buffer for future growth
• Building automation system that displays how building is performing in real time and provides opportunity to fine-tune for optimal performance throughout building’s life span
Other key sustainability features include:
• Restorative site – 2 biofiltration basins that responsibly manage stormwater, reduce risk of flooding, and naturally filter water
• Water conversation – low flow fixtures and native, drought-tolerant landscaping for hot Santee climate
• Alternative transportation – incentives and charging stations for electric vehicles, bike racks and lockers for short- and long-term storage, and direct connections to the local public transit system
• Waste reduction – 88% of construction waste diverted from landfill, which is equivalent to 196 tons of recycled construction waste
• Healthy work environment – healthy materials to eliminate toxins and reduce VOCs for better air quality, as well as ample daylighting and outdoor paths for an escape into nature
“Creating a Zero Net Energy building with the strict and energy-intensive requirements of an archive facility was a highly technical and first-of-its-kind challenge for the County. The stok team brought unparalleled technical energy expertise, the know-how to work within financial constraints, and educational capabilities to help the County achieve our ambitious ZNE and LEED Gold targets. Simply said, the County of San Diego Energy and Sustainability Program wouldn’t be where it is today without stok.”
–Susan Freed, Project Manager, Energy & Sustainability Program at the County of San Diego
Outcome: The East County Office and Archives is on track to become the first Zero Net Energy archive facility in the U.S., as well as achieve its targeted LEED v4 Gold certification. Combining several governmental and administrative departments, the new building is a valuable public resource and amenity for the City of Santee and a testament to the County of San Diego’s commitment to a high performance real estate portfolio for the benefit of its residents.
stok will continue to provide measurement and verification services until the facility’s ZNE performance is verified. stok is also providing training for building occupants to understand how the building operates and the intent behind the ambitious performance targets, serving as an opportunity for improved engagement and feedback for County employees.
For its exceptional performance, the East County Office and Archives received the 2020 Government/ Public Building Award of Merit from Engineering News Record California. The project also received a 2020 Orchid Award for Architecture from the San Diego Architectural Foundation.
PHOTOGRAPHY: Chipper Hatter