This project targeted the development of a software tool, BEopt-CA (Ex) (Building Energy Optimization Tool for California Existing Homes), that aims to facilitate balanced integration of energy efficiency (EE), demand response (DR), and photovoltaics (PV) in the residential retrofit 1 market. The intent is to provide utility program managers and contractors in the EE/DR/PV marketplace with a means of balancing the integration of EE, DR, and PV.The National Renewable Energy Laboratory's BEopt software was enhanced by adding capabilities in the following areas:• Existing home retrofit analysis • Retrofit measures and cost data • Utility tariff capabilities • Utility cost-effectiveness tests • Incentives for PV and whole-house efficiency • Demand response.These new BEopt-CA (Ex) capabilities are now available in the current version of BEopt (https://beopt.nrel.gov) and can be accessed by selecting the California-specific mode upon launching the program.BEopt was connected to the new California Simulation Engine (CSE) to provide capability for software-to-software comparisons with EnergyPlus via the BEopt Test Suite. 2 Further integration of BEopt and CSE could provide: (1) parametric (and optimization) capabilities for CSE in Title 24 development; and (2) a front end for a public CSE-based Title 24 user tool. This report includes example analysis results to demonstrate some of the new BEopt capabilities. Utility cost test results are given for optimized building designs combining EE and PV on the path to zero net energy over a range of rate types, house types, fuel types, energy consumption levels, and climates.1 Retrofit analysis was a major focus of the project, but many of the new BEopt capabilities are also applicable to new construction. 2 The BEopt Test Suite automates thousands of runs for multiple simulation engines across a full range of building characteristics and energy efficiency measures. Statistically relevant end-use data from two existing California communities were also developed for use in validation.6 Conclusions .