Launch of new guidance on net zero carbon definition

Launch of new guidance on net zero carbon definition

To deliver real progress on net zero, we need to develop a common understanding of what it means for buildings, in practice and in detail.

The Chartered Institution of Building Services Engineers (CIBSE) and London Energy Transformation Initiative (LETI) will be launching new guidance, developed to provide industry-wide definitions and address frequently asked questions during an online launch event on 7 April 2022.

This guidance, led by Julie Godefroy, Head of Sustainability for CIBSE and Clara Bagenal George, Associate at Elementa Consulting, builds on the definitions developed by WLCN/LETI in summer 2021 and looks at whole life, embodied – referring to total emissions and removals associated with an asset throughout the whole life cycle of an asset; upfront carbon – referring to emissions associated with materials and construction processes up to practical completion; operational energy; and operational water. Crucially these new definitions are based on meeting operational energy and embodied carbon targets and generating energy from renewable sources.

The new guidance from CIBSE and LETI provide more detail and are intended to be applied consistently in as many real-life situations are possible.

An initial industry survey on the FAQs illustrated that there was general agreement about acknowledging achievements in working towards net zero operational energy at different project stages, with the provision that continued progress is verified on an annual basis.

This guidance is for professionals from different disciplines, clients, investors, and occupants so they can be aligned in language and understanding of net zero targets and achievements.

With a growing suite of CIBSE guidance and digital tools relating to embodied carbon, net zero and creating a circular economy practice, this exciting new resource further demonstrates the impact of industry collaboration and communication in responding to challenges presented by the climate emergency.

The launch event is online and free to attend. Attendees will be invited to participate in an interactive Q&A as part of an engaging afternoon session hosted by Clara Bagenal George, and Julie Godefroy.

Launch of new guidance on net zero carbon definition

Find out more about CIBSE’s ongoing work around net zero via


CIBSE publishes guidance providing best practice advice and is internationally recognised as authoritative design guidance for building services. The CIBSE Knowledge Portal, which makes guidance available online to all CIBSE members, is the leading systematic engineering resource for the building services sector.

For more information about the Institution, please visit

About LETI

LETI is a network of built environment professionals that are working together to put the UK on the path to a zero carbon future. In 2020, LETI launched the Climate Emergency Design Guide and the Embodied carbon primer, which outlines requirements of new buildings to ensure our climate change targets are met. in 2021, LETI published guidance on Hydrogen, Carbon Alignment, a Client Guide for Net Zero Carbon Buildings and the Climate Emergency Retrofit Guide.