TM39 Building Metering and Monitoring (2026)

Since the 2009 edition of TM39, metering installations have grown to meet new challenges such as technological advances; the climate crisis; rapid growth in renewable energy; changes in national and global fuel supply infrastructure and pricing; growing demand for load management over a range of timescales, and more.

The 2026 revision of TM39 benefits from experience with existing metering installations. Good metering yields both general and project-specific insights into energy use, enabling better energy management and benchmarking. The design and facilities teams can use metered data to correlate predicted performance with in-use outcomes, fine-tuning as they go. Metered data can benefit industry, government, researchers and occupiers, and can feed into more powerful methods of building energy certification during design and in use.

Good metering forms the foundation of building performance that is proven and verified by successful and reliable measurement. In turn, measured building performance forms the basis of compliance with many climate-related disclosure standards and items of legislation.

TM39: Building metering and monitoring describes and promotes best practice for the design, specification, installation, commissioning, data export, and use of energy metering and submetering data in non-domestic buildings. It provides guidance for new and existing buildings and is a resource for designers, owner–occupiers, facilities managers, landlords (and letting/managing agents acting on their behalf), tenants, managers, staff and all others who benefit from the energy data that metering and monitoring can provide

1 Introduction

1.1 The TM39 method

2 Develop the meter strategy

2.1 Survey the building infrastructure

2.2 Define the TM39 metering boundary

2.3 Determine the strategy

3 Apply the strategy within the metering boundary

3.1 Document the energy and water flow across and within the boundary

3.2 Fine-tune the strategy considerations

3.3 Strategy review before proceeding

3.4 Decide which items to meter

4 Meter selection

4.1 Typical uses for meter data

4.2 Hardware selection and sizing

4.3 Meter accuracy

4.4 Meter placement

4.5 Meter communications (‘comms’)

4.6 Data collection and visualisation system

5 Documentation

5.1 Meter naming convention

5.2 Meter point schedule

5.3 Site plan drawing marked to show meter locations

5.4 Examples of meter schematics and schedules

6 Review for a ‘sanity check’

7 Meter installation and commissioning

7.1 Installation troubleshooting

7.2 Meter labelling

7.3 Meter commissioning

7.4 Commissioning procedure

7.5 Load-testing electricity meters

7.6 Specific guidance for commissioning thermal meters

7.7 Final commissioning documentation for O&M manual and building log book

7.8 Ongoing commissioning guidance

8 Meter reading

8.1 Manual meter readings

8.2 Automatic meter readings

9 Data validation

10 Data analysis and user engagement

10.1 Data visualisation: minimum requirements

10.2 Utility bill validation

10.3 Data analytics: options to consider

10.4 Tenant billing

10.5 Using temporary meters

10.6 GSHP monitoring to predict group loop performance

Appendix 1: Supporting items

A1.1 Key activities mapped onto RIBA stages

A1.2 Glossary

A1.3 Related documents

A1.4 Commissioning checklists

Appendix 2: Thought pieces

A2.1 Building regulations and how they apply to meters in new and existing buildings

A2.2 Metering energy use in new buildings: example flowchart

A2.3 Common items to submeter in a mixed-use development

A2.4 Cybersecurity

A2.5 Common metering pitfalls

A2.6 Metering for export/trading

A2.7 ‘Shipperless’ meters

A2.8 Good practice for metering lift and escalator energy

A2.9 Metering in disturbed electrical environments

A2.10 Metering for ambient loop systems

A2.11 Ground source heat pump system performance monitoring

A2.12 Tenant billing

A2.13 Understanding how embedded manufacturer controls can affect system performance

Appendix 3: Case studies

A3.1 Case study: peak heat monitoring (Arts University Bournemouth)

A3.2 Case study: metered heat pump and energy system performance (Gloucestershire College)

A3.3 Case study: Halving the Half — baseload reduction and BESS project (Cardiff Metropolitan University)

A3.4 Case study: observations on submetering from operational buildings 138

References and bibliography 142

Lead author: Ellen Salazar (CIBSE Head of Building Services Engineering)

Working Group Technical Panel: Ian Allan (Switch2 Energy), Claire Das Bhaumik (Inkling), Peter Brown (Savills), Lee Cleeton (Verte Ltd), Paul Clements (D2E), Joshua Cooper (Hildebrand), Richard Daniels (DfE), Nicholas Darling (SES (Engineering Services) Ltd), Shivraj Dhaka (Confederation of Indian Industry), Stuart Dixon (SES (Engineering Services) Ltd), Phil Draper (Energy and Recharge Consultant), Steve Edge (Introba), Lewis Edwards (Morgan Sindall), Esam Elsarrag (Hoare Lea), Keegan Farrelly (BESA), Colin Gadd (Electracom Projects), David Harden (Enica), Simon P. Hardy (Bovis Construction-Europe), Richard Hipkiss (Elemental Consulting Group), Richard Jackson (Arup), Ashish Jain (Aeon Consultants), James Lester (Benchmark Electrical Design and Consultancy), Cherry Li (Beyond Engineering Consulting Ltd), Roger Macklin (Hoare Lea), Jyotirmay Mathur (Malaviya National Institute of Technology Jaipur), Laurie McKelvie (IES), Tim May (Aphex Systems), Tony Mayo (Hilson Moran), Adam Middleton (KJ Tait), Simon Mitchell (CBRE GWS), Adam Newman (Insite Energy), Barry Paschali (Paschali Energy and Environmental Consultants), Emmanouil Perisoglou (University of Cardiff), Daniel Piasecki (Oldham Council), Ashish Rakheja (Aeon Consultants), Tom Randall (Arup), Matthew Rose (MWA Technology), Caspar Sayany (Ground Source Engineering), Dominic Slaven (D3 IoT), Philip Tamuno (NHS Homerton), Phil Tower (University of Huddersfield), Martin Trentham (Tilbury Douglas), Joe Valentine (Max Fordham), Martin Wardell (MWA Technology), Shen Wei (University College London), Chris Yates (Specialist Consultant), Yangang Xing (Nottingham Trent University)

Technical content authors and contributors: Ian Allan (Switch2 Energy), Karthik Anniappan (Forest Rock Systems), Quinten Babcock (Transport for London), Chris Bishop (DMS Ltd), Laura Bishop (Hillside Infinitas Ltd), Bill Bordass (Usable Buildings Trust), John Brenton (The Energy Consortium), Peter Brown (Savills), John Carroll (NDY a Tetra Tech Company), Dave Cooper (LECS UK), Joshua Cooper (Hildebrand), Paul Clements (D2E), Richard Daniels (DfE), Nicholas Darling (SES (Engineering Services) Ltd), David Deacon (Spirax Sarco), Shivraj Dhaka (Confederation of Indian Industry), Stuart Dixon (SES (Engineering Services) Ltd), Phil Draper (Energy and Recharge Consultant), Lewis Edwards (Morgan Sindall), Ryan Elliott (Hoare Lea), Esam Elsarrag (Hoare Lea), John Field (Native Hue), Colin Gadd (Electracom Projects), Vishal Giga (Spirit Energy), Darragh Gleeson (IES), David Harden (Enica), Simon P. Hardy (Bovis Construction-Europe), Richard Hipkiss (Elemental Consulting Group), Richard Jackson (Arup), Mat King (Spirax Sarco), Ian Knight (K2n Ltd/Cardiff University), Dominic Kolb (The Energy Consortium), Leonora Lang (Arup), James Lester (Benchmark Electrical Design and Consultancy), Graham Lewis (Cardiff Metropolitan University), Chuan Lim (Foster and Partners), Stephen Lowndes (Carbon & Energy Fund), Roger Macklin (Hoare Lea), Tim May (Aphex Systems), Tony Mayo (Hilson Moran), Laurie McKelvie (IES), Paul Meenan (C2C Rail), Emeka Efe Osaji (University of Hertfordshire), Phil Pearson (Pearson Consult), Emmanouil Perisoglou (University of Cardiff), Mark Ponzini (Land Sec), Mathew Preece (Arthian), Mark Rimell (Carlo Gavazzi UK), Matthew Rose (MWA Technology), Vince Ruane (RCDC), Timo Rumble (RCDC), Ellen Salazar (CIBSE), Caspar Sayany (Ground Source Engineering), Mark Simmons (Switch2 Energy), Phil Tower (University of Huddersfield), Martin Trentham (Tilbury Douglas), Chris Yates (Specialist Consultant)

This publication is supplied by CIBSE for the sole use of the person making the download. The content remains the copyright property of CIBSE

Technical draft reviewers: Quinten Babcock (Transport for London), Claire Das Bhaumik (Inkling), Laura Bishop (Hillside Infinitas Ltd), Bill Bordass (Usable Buildings Trust), Robert Cohen (Verco), Darren Coppins (Built Physics Ltd), Jennifer Cox (Cundall), Richard Daniels (DfE), Chris Davidson (Genuis Energy Lab), Phil Draper (Energy and Recharge Consultant), John Field (Native Hue), Grace Foo (DeltaQ Pty Ltd), Stephen Gathergood (Vinci Facilities), Mark Gifford (IES), Darragh Gleeson (IES), Colin Goodwin (independent consultant), David Harden (Enica), Simon P. Hardy (Bovis Construction-Europe), Richard Hipkiss (Elemental Consulting Group), Roger Hitchin (independent consultant), Keith Horsley (BECA), Phil Jones (Building Low Carbon Solutions), David Kingstone (Buro Happold), Ian Knight (K2n Ltd/Cardiff University), James Lester (Benchmark Electrical Design and Consultancy), Graham Lewis (Cardiff Metropolitan University), Stephen Lowndes (Carbon & Energy Fund), Rob MacWhannell (Better Building Partnership), Tim May (Aphex Systems), Tony Mayo (Hilson Moran), Emeka Efe Osaji (University of Hertfordshire), Gary Parker (Electrical Contractors Association), Neil Pennell (Land Sec), Mark Ponzini (Land Sec), Duncan Rae (Genuis Energy Lab), Mia Richardson (Schneider Electric), Matthew Rose (MWA Technology), Divyanshu Sood (University College Dublin), John Taylor (BSRIA), Phil Tower (University of Huddersfield), Chris Yates (Specialist Consultant)

Peer reviewers: David Arnold (Troup Bywaters + Anders LLP), Eszter Gulacsy (Mott MacDonald Ltd), Denise Newbold (MAPP Property Management Ltd)

Acknowledgements

The Institution is grateful to everyone who gave their time and expertise to this update and to the following companies that contributed material for inclusion in this publication: Benchmark Electrical Design and Consultancy, Carlo Gavazzi UK, Elemental Consulting Group, Enica, Hilson Moran, IES, K2n Ltd, MITIE, Native Hue, SES (Engineering Services) Ltd, Spirax Sarco, Switch2 Energy, the Building Engineering Services Association (BESA), Transport for London (TfL).

Permission to reproduce extracts from British Standards is granted by BSI. British Standards can be obtained in PDF or hard copy formats from BSI Knowledge: https://knowledge.bsigroup.com or by contacting BSI Customer Services for hardcopies only: Tel: +44 (0)20 8996 9001, Email: [email protected]