Overview
CEN ISO/TR 52120-2:2022 (identical to ISO/TR 52120-2:2021) is a Technical Report that explains and justifies ISO 52120‑1. Its purpose is to consolidate informative material needed for correct understanding, practical use and national adoption of the ISO 52120 series on the energy performance of buildings and the contribution of building automation, controls and building management (BAC / BMS / TBM). The report complements normative requirements by providing background, rationale, worked examples and an accompanying spreadsheet to aid implementation.
Key topics
- Purpose and scope: Guidance to support correct interpretation and application of ISO 52120‑1 across national and project contexts.
- Effect of BAC and TBM: Explanation of how building automation, control accuracy, control functions and control strategies influence building energy performance.
- BAC function descriptions: Informative details for major control domains including:
- heating control and distribution
- domestic hot water (DHW) control
- cooling control
- ventilation and air‑conditioning control
- lighting control
- blind/shading control
- Two assessment methods:
- Method 1 - detailed, time‑step based calculation method (for in‑depth simulation and precise impact assessment).
- Method 2 - BACS factor method (simplified approach for quicker estimates).
- Method selection and assumptions: Guidance on choosing between detailed and simplified approaches, required time steps, input data, calculation information and simplifying assumptions.
- Supporting material: Worked examples, symbols/definitions and an accompanying spreadsheet to facilitate consistent application.
- Normative references: Links to ISO 52120‑1, ISO 7345 and ISO 52000‑1 for related EPB (Energy Performance of Buildings) principles.
Applications
- Energy performance modelling and simulation that accounts for BMS/BAC impacts.
- National or regional adoption and harmonization of ISO 52120‑1 in building codes and EPB frameworks.
- Specification and procurement of building automation and control systems with quantified energy contribution.
- Facility management and retrofit planning to estimate energy savings from control upgrades.
- Compliance assessment and reporting where BAC influence on energy metrics must be demonstrated.
Who should use this standard
- Building energy modelers and simulation engineers
- HVAC and BMS designers/integrators
- Energy assessors and certification bodies
- Facility managers and building owners
- Policy makers and standardization bodies adopting EPB requirements
Related standards
- ISO 52120‑1 - General framework and procedures (normative companion)
- ISO 7345 - Thermal performance - Physical quantities and definitions
- ISO 52000‑1 - Overarching EPB assessment framework
- Supersedes: CEN/TR 15232‑2:2016
This Technical Report is published by CEN in collaboration with ISO (CEN/TC 247 and ISO/TC 205) and is intended to make the normative ISO 52120‑1 easier to interpret and apply in practice.
