Case Studies


Environmental projects

Many of our projects involve water purification, material recycling, and green energy generation, such as the Miners Ranch Water Treatment Plant Improvement project, a progressive design build project that expanded plant capacity from 14 to 21 million gallons per day of clean water to serve approximately 6,700 households in Butte County.


Choosing projects and partners that align with our values

Case Study: Choosing projects that support the environmental initiatives

Overaa actively pursues projects that include water purification, water recycling, material recycling, and green energy generation such as solar, cogeneration, and biofuel. 

In 2009, Overaa invested in people and equipment to increase our ability to compete in the water resource and municipal infrastructure market. Today, more than half of our volume of work involves water resource management, material resource management, and renewable energy. We have been named one of the Top Environmental Firms in the nation three years in a row by Engineering News Record (ENR).

Additionally, we seek out LEED projects, Net Zero projects, ParkSmart projects, and other certified green building projects. We built the world’s first rotating laboratory, The FLEXLab at Lawrence Berkeley National Laboratory to support research in building system efficiency such as building envelopes, windows, and ventilation, and energy control systems.

We recently built the largest commercial kitchen in Northern California, the Central Commissary, for  Oakland Unified School District. That project was named a Top Environmental Project Merit Award by ENR in 2021. The project uses 35% less electricity than comparable structures thanks to extensive daylighting, carbon dioxide-based refrigeration, waste heat recapture system, and full building systems integration.

100% SOLAR Headquarters

Since 2016, Overaa has invested in renewable energy to power operations.


100% Solar Powered, Centralized Operations

Case Study: Going green 

Our Richmond headquarters – including our prefabrication yard and shop – is 100% solar powered

In 2016, we added our first solar array to our rooftop and in 2018, we added an additional 5,852 SF carport structure equipped with solar panels. Together, the system produces approximately 194,151 KW per year of energy, enough to power our offices, shop, and prefabrication yard most days of the year. On days that this is not enough, we source our supplemental energy from MCE Solar One, a 10.5 megawatt solar farm that Overaa helped design-build in 2018.

The energy generated from Overaa’s solar system is equivalent to 137 metric tons of carbon dioxide emissions avoided. This is equal to 23.9 homes’ electricity use in one year, removing 29.1 passenger vehicles from the road each year, or the carbon sequestered by 162 acres of US forest in one year.


sustainable Stewardship

Most of our clients are interested in investigating methods and materials that can lower the impact of construction on natural resources and carbon emissions. Our in house team provides thoughtful analysis and options.


Certified Green Building Specialists

Case Study: Education, training and engagement in the newest approaches to sustainability

Overaa LEED certified professionals get involved with design teams early in the development phase to help analyze materials and methods and to incorporate concepts to achieve LEED accreditation. From our knowledge base, we provide critical value analysis for project teams to make strategic decisions during the project development.  

We also have Stormwater Pollution Prevention Plan (SWPPP) certified staff, ready to help you implement and maintain your project’s SWPPP that was developed during design. Our comprehensive SWPPP services cover: regulatory compliance and compatibility and feasibility for both construction as well as industrial general permits. 

In addition to LEED, our team uses benchmark systems to validate sustainable design approach for our projects including Living Building Challenge, ParkSmart, CHPS, Labs 21, SITES, Well Building Standard, Buy Clean California Act, Architecture 2030, SB 100 etc.