What is a TRM?


In 1999, VEIC won a three-year contract with the Vermont Public Service Board (PSB) to administer the first statewide energy efficiency utility in the country under the name Efficiency Vermont. Initially, Efficiency Vermont relied on custom engineering analysis for each project. As services multiplied and demand for energy efficiency services grew, however, Efficiency Vermont was challenged to develop an authoritative prescriptive analysis tool that would decrease the administrative and engineering resources required by each project, while providing accurate and up-to-date data for efficiency measures.


The first Technical Reference Manual (TRM) was created by VEIC in 2000 to generate consistent and transparent documentation of energy-efficient measures. The TRM is used by program administrators to plan for, quantify, report, and document savings.

The TRM approach has since been adopted by other states to provide detailed state-specific information including algorithms for kilowatts, kilowatt-hours, net-to-gross calculations, interactive effects, fossil fuel impacts and water savings, hours of use assumptions, install service rates, lifetime savings, and incremental costs. Information is organized by program (commercial, multifamily, low-income, etc.) and measure (direct install, retrofit, time of sale, etc.).

Each measure used by Efficiency Vermont (and its parent, VEIC) is documented and included in the Vermont TRM after passing through four stages of development. The four stages include:

  • Planning by program managers and technology experts.
  • Development of measure characterizations and quality-assurance by evaluation, measurement, and verification (EM&V) staff of technical analysts, engineers, consulting resources, and marketing.
  • Regulatory oversight and review by state regulators, third-party independent evaluation teams, and EM&V services group.
  • Implementation by marketing staff, customer service staff, information technology staff, and EM&V service staff.

The TRM is continually updated to support existing technologies and savings assumptions, and to develop new measure characterizations for emerging technologies and prescriptive programs. An annual version of the Savings Verification TRM, documenting all measure characterization assumptions used in a given program year, is published annually and submitted to the state regulators and EEU stakeholders.

Over the last decade VEIC has assisted numerous states and utilities in developing and managing TRMs, including Maine, Massachusetts, Rhode Island, Ohio, Illinois, Mid-Atlantic, District of Columbia, and others.


  • A Higher volume of efficiency measures can be implemented with low variability in results.
  • Fewer resources are required for delivery of energy efficiency services.
  • Fewer administrative costs are required for project completion.
  • Greater transparency and consistency is achieved in energy efficiency service delivery.
  • The annually updated TRM provides accurate and up-to-date market data and technology information.