ISO 50002-2:2025

Overview

ISO 50002-2:2025 - "Energy audits - Part 2: Guidance for conducting an energy audit using ISO 50002-1 in buildings" provides targeted guidance on applying ISO 50002-1 specifically to audits of buildings (single or groups, new or existing). It is supplementary to ISO 50002-1 and focuses on the particularities of built environments - building fabric, envelope and technical building systems - while excluding process audits, specific isolated systems (e.g., compressed air) and transport (see ISO 50002-3).

Key topics and technical requirements

This guidance expands on the general requirements of ISO 50002-1 with building-specific topics, including:

• Audit planning - clarifying owner/operator/tenant relationships, defining audit objectives (energy reduction, GHG/emissions, indoor environment quality), scope and boundaries, and estimating audit cost.
• Initial agreement and meetings - conducting opening and closing meetings to align stakeholders and verify findings.
• Data collection - collecting building energy data, operational information and benchmarking values; Annex A lists typical data that can be collected.
• Measurement plan - preparing preliminary data analysis and a targeted measurement plan for energy end uses and technical systems.
• Site visit and fieldwork - managing on-site inspection of building fabric, services and controls.
• Analysis and evaluation - assessing current energy performance, identifying and evaluating energy performance improvement opportunities, and prioritizing actions.
• Reporting - structuring audit reports with required content to support decision-making.
• Competence of the energy auditor - ensuring auditors have building-specific technical knowledge.

Key definitions included: building, building envelope, building fabric, building service, and technical building system - all central for accurate scoping and analysis.

Practical applications and who should use this standard

ISO 50002-2 is intended for:

• Energy auditors and consultants conducting energy audits in buildings
• Facilities managers and building owners seeking to reduce energy use, costs and GHG emissions
• Building operators and tenants involved in multi-stakeholder properties
• Organizations integrating audit outcomes into an Energy Management System (EnMS), including ISO 50001-aligned programs

Practical uses:

• Developing measurement plans and site visit protocols for commercial, institutional or residential buildings
• Identifying energy efficiency measures, improving occupant comfort, informing asset management and capital investment decisions
• Benchmarking building energy performance against national or international reference data

Related standards

• ISO 50002-1 - General requirements with guidance for use (normative reference)
• ISO 50002-3 - Process audits (separate, for non-building processes)
• ISO 50001 - Energy management systems (EnMS) - for implementing audit findings into ongoing management

Keywords: ISO 50002-2, energy audit, buildings, ISO 50002-1, building energy performance, technical building systems, building envelope, energy efficiency.