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.