ISO 50021:2019

Overview

ISO 50021:2019 - "Energy management and energy savings - General guidelines for selecting energy savings evaluators" provides guidance on choosing qualified people (or teams) to determine ex‑post (realized) energy savings for projects, organizations and regions. The standard defines roles (e.g., lead energy savings evaluator, selector), sets out principles for selection, and recommends the knowledge, skills and competence needed to deliver credible, transparent and impartial energy savings evaluations. Selecting evaluators who calculate predicted energy savings is explicitly out of scope.

Key Topics

• Scope and objectives: Applicable at project, organization and regional levels; relevant for internal and external evaluators; focused on ex‑post energy savings evaluation.
• Selection considerations: Final objectives, subject of evaluation (project, organization, city/region), evaluation approach, reporting requirements, and budget/time constraints.
• Approaches and methods: Top‑down (entity or indicator‑based) and bottom‑up (measure‑based, modelling, calibrated simulation, direct comparison); methods should be agreed before evaluation.
• Principles for selection: Confidentiality, impartiality, transparency, competence and professional conduct.
• Roles and responsibilities: Definitions for evaluators, lead evaluators and selectors - who leads, reviews and assures consistency of the evaluation.
• Competence and credentials: Recommended elements to assess knowledge, skills, education, experience and records; Annexes provide examples of selection methods, required knowledge and skills, demonstration of competence and acceptable credentials.
• Reporting: Requirements on accuracy, documentation, format, units (kWh, GJ, etc.), confidentiality and whether CO2 equivalents are included.

Applications

ISO 50021 is practical for:

• Energy managers and sustainability teams selecting internal or external evaluators to verify realized savings from Energy Performance Improvement Actions (EPIAs).
• Programme administrators, regulators and financing institutions that require independent, credible ex‑post evaluation for policy assessment, subsidy or loan verification, or compliance reporting.
• Consultants and evaluation firms preparing bids or structuring qualifications to meet client requirements for ex‑post energy savings verification.

Using ISO 50021 helps ensure energy savings evaluations are credible, consistent and aligned with stakeholder objectives - improving financial decision‑making, policy assessment and energy management outcomes.

Related Standards

• ISO 17741, ISO 17742 and ISO 50047 - referenced as providing additional approaches and methods for determining energy savings.
• ISO 50001 - related energy management system terminology and context.

Keywords: ISO 50021:2019, energy savings evaluators, energy savings evaluation, ex‑post verification, energy management, evaluator competence, top‑down, bottom‑up, EPIA.