This session details how a Walmart store in Southern California is evaluating the impacts of installing an integrated suite of precommercial energy efficiency technologies, with the goal of achieving at least 20% reduction in electricity consumption. Learn about different precommercial technologies and understand the complexities of pursuing such a project. The Big Box Efficiency Project is evaluating the impacts of installing an integrated suite of precommercial energy efficiency technologies to an existing Walmart Supercenter in Southern California. During this project, partners from the California Energy Commission, Walmart and Center for Sustainability will assess, install, test, measure and demonstrate the effectiveness of these technologies with a goal of achieving a minimum 20% reduction in electricity consumption. The project team will also be evaluating the impact of these technologies on utility and maintenance costs, human comfort and operational efficiency. Predicting the technical and financial performance of energy efficiency technology packages is complicated. This is due to a combination of factors, including untested interactive effects and unproven savings benefits of precommercial technologies. The objective is to model and test technologies and their accompanying systems, with the goal of creating a blueprint for large commercial buildings across California with similar end‐use and system characteristics. The project will also directly impact Walmart’s future store specifications that can be replicated and deployed in other buildings with similar end-use and system characteristics. This session will feature a project overview from the project manager at Center for Sustainable Energy. We will provide a review of the site hosts traditional approach for energy efficiency projects as well as specific considerations for analyzing and installing pre-commercial technologies in an existing retail store. Finally, a Center for Sustainable Energy lead engineer will provide an in-depth review of the different precommercial energy efficiency technologies used in the project.