Energy Trust of Oregon is seeking proposals for a contractor to perform a comprehensive impact evaluation of Energy Trust's commercial building energy efficiency program, the Existing Buildings (EB) program, for the 2025 and 2026 program years. This two-year evaluation will utilize a retrospective evaluation approach to the 2025 program year and a concurrent evaluation approach for the 2026 program year, representing the first instance of concurrent evaluation for an Energy Trust program-level impact evaluation. The evaluation will cover four main program tracks: Custom, Lighting (including downstream, direct-install, midstream/buydown and street lighting measures), Standard (prescriptive, midstream/buydown, and direct install), and Strategic Energy Management (SEM). The evaluation scope includes: developing reliable estimates of EB program gas and electric savings to establish realization rates by year and track; developing estimates of electric and gas demand savings at the measure category level and for the program overall; reporting observations and recommendations to help Energy Trust understand substantial deviations from claimed savings; and improving ex ante savings estimates and the effectiveness of future engineering studies and impact evaluations. The contractor will be responsible for conducting study kick-off meetings, reviewing program data and developing comprehensive 2025 and 2026 work and sampling plans, planning data collection and facility operator interviews, conducting detailed data collection and facility operator interviews, performing impact analysis, reporting observations and recommendations, delivering final evaluation reports with presentations, and ongoing project management. The 2025 sampling plan should be constructed to develop savings estimates and realization rates with 10% relative precision at 90% confidence for program level electric and gas savings and 15% relative precision at 90% confidence for track level electric and gas savings. The 2026 sampling plan follows a concurrent evaluation approach with sample draws at two distinct periods: on or soon after July 1st, 2026 (for projects completed January 1 - June 30, 2026) and on or soon after January 21st, 2027 (for projects completed July 1 - December 31, 2026). Data collection methods will include desk reviews, customer interviews, virtual site visits, in-person site visits, and metering. For SEM projects, the evaluator will verify the persistence of savings through control set point verification, scheduling changes, and operations and maintenance changes. The contractor must develop detailed site- or project-specific evaluation plans (SSEPs) for sampled Custom and SEM projects with savings above the 75th percentile, including proposed data collection methods, evaluation methods (IMPVP option choice or alternative), and specific data points to be collected. The evaluation requires compliance with utility customer information confidentiality agreements and data security requirements. The contractor will provide monthly status reports, bi-weekly check-in meetings, draft results workbooks for non-SSEP projects, and detailed draft reports for SSEP projects. Final deliverables include comprehensive evaluation reports for both 2025 and 2026 program years with executive summaries, introductions describing evaluation and research questions, summaries of methods including sampling and recruitment, results and findings with charts highlighting key findings, conclusions and recommendations, appendices with detailed tables and crosstabulations, and confidential appendices containing site level reports and results. The contractor will also develop and present 20-minute presentations of evaluation findings for each program year at public evaluation webinars hosted by Energy Trust's evaluation team.