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19.04.23  Operational Modelling Guide

The modelling guide explores how a building's meter readings can be estimated at design stages, and how this understanding can be used to inform and improve designs, enabling more confidence that operational energy targets can be achieved.  This guide will be a useful resource for all stakeholders involved or interested in delivering net zero operational carbon projects. The guide addresses why we need to use operational energy performance modelling, and the key pieces in the jigsaw needed to make it effective for any project.

→  Download the Operational Modelling Guide here

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13.03.23  Specification and Procurement Guide

This guide has been created to support designers and Contractors who are facing the difficult task of trying to reduce embodied carbon without a clear roadmap to follow.


The Low Embodied Carbon Specification and Procurement guide is intended to support that process by considering specification and procurement in more detail, thereby helping to reduce the embodied carbon performance gap between the design intent and the reality of construction.

→  Download the Specification and Procurement Guide here

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06.03.23  Retrofit vs Rebuild Unpicker

The Retrofit vs Rebuild Unpicker provides guidance on how to compare whole life carbon for a retrofit, versus its demolition and rebuild. This document aims to help review whole life carbon comparisons between rebuild and retrofit scenarios.

This guidance helps establish whether the assessment and comparison are as fair and like-for-like as possible, technically robust and transparent.

→  Download the Retrofit Unpicker here

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09.01.23 Embodied Carbon Case Studies

The LETI Embodied Carbon Case Studies are a selection of projects in the UK chosen to showcase good practice regarding consideration of embodied carbon and whole life carbon principles in a clear, and consistent format. The aim of their development has been to create a format, with a clear and understandable scope, to provide a useful means of sharing lessons learned to reduce embodied carbon while striking a balance of reporting robust metrics to back up the ‘carbon story’ behind the analysis and project procurement.

→  Download the Embodied Carbon Case Studies here

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26.04.22  Circular Economy 1-pager

LETI's one page summary from the Circular Economy Workstream provides a definition and explanation of what circularity in a built environment context comprises, a circular strategies hierarchy, primary actions for the built environment industry to prioritise, and suggests key circularity metrics for professionals to test. The summary also references the relationship between circularity and whole life carbon reductions which requires further attention.

→  Download the Circular Economy 1-pager here

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07.04.22  LETI-CIBSE Net Zero FAQs

Previous LETI publications provide guidance on how to define good, when it comes to new buildings and retrofit of homes. But what does this mean in the context of ‘net zero carbon’? This guidance from LETI and CIBSE builds on the WLCN-LETI carbon definitions to try to make sure that the definitions are applied consistently and robustly in as many real-life situations are possible.

→  Download the LETI-CIBSE Net Zero FAQs here

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21.10.21  Climate Emergency Retrofit Guide

This guide shows how we can retrofit our homes to make them fit for the future and support the UK’s Net Zero targets.  We define energy use targets for existing homes and provide practical guidance on how to achieve them.  The guide is useful for architects, engineers, Local Authorities, social landlords, energy professionals, contractors and clients looking for guidance about best practice retrofit.

→  Download the Climate Emergency Retrofit Guide here

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11.08.21  Client Guide for Net Zero Carbon Buildings

As our global community struggles to keep up with their growing climate commitments, the LETI Client Guide for Net Zero Carbon Buildings will help all construction clients navigate their way through a rapidly changing construction industry. It pulls together key details from numerous LETI documents and publications, which cover the ways in which briefing, designing, procuring, constructing, occupying, managing and valuing buildings must change.

→  Download the Client Guide for Net Zero Carbon Buildings here

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27.05.21  Whole Life Carbon One Pager

We must urgently reduce carbon emissions. Whole Life Carbon analysis is the only approach that allows the emissions of a project to be considered holistically over its lifespan. This 1-page summary illustrates the concept of Whole Life Carbon with graphics that explain the measurement scopes, key terminology, an example building cycle and guidance on reducing emissions.

→  Download the Whole Life Carbon One Pager here

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27.05.21  Embodied Carbon One Pager

Embodied Carbon is an increasingly large component of Whole Life Carbon. Following the release of the Embodied Carbon Primer, this 1-page summary introduces the concept of the Embodied Carbon cycle as well as a clear definition. It is shown together with key methods of reducing emissions that can be embedded into a project strategy and taken through to consideration of building elements. The one pager also communicates the importance of Circular Economy principles.

→  Download the Embodied Carbon One Pager here

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27.05.21  Embodied Carbon Target Alignment

A key issue the industry faces when setting and using Embodied Carbon targets is the lack of consistent measurement, leading to mis-aligned benchmarks, project targets and claims. This document has been produced to standardise performance and reporting scopes to meet IPCC recommendations for urgent emissions reductions. The paper sets out a rating system that can be used to track the urgent performance improvements needed from now until 2030. These targets align both RIBA and LETI embodied carbon targets

→  Download the Whole Life Carbon One Pager here


10.02.21  Hydrogen: a decarbonisation route for heat in buildings?

Hydrogen as a means to deliver energy is often touted as a viable solution to assist in meeting the UK’s net zero carbon target. This has a major influence on the need, or otherwise, to enhance new-build energy efficiency and the energy retrofit of our existing stock. Why enhance our buildings if the current use of natural gas can be simply switched to zero-carbon hydrogen? In this short discussion paper, LETI have sought to investigate this further, examining to what extent hydrogen is likely to be used.

→  Download the Hydrogen Paper here


27.01.20  Climate Emergency Design Guide

We are in a climate emergency and urgently need to reduce carbon emissions. This guide outlines the requirements of new buildings to ensure our climate change targets are met. A definitive journey is set out, beyond climate emergency declarations, into a net zero carbon future. It is specifically aimed towards developers/landowners, designers, policy makers and the supply chain. The guide aims to help to define ‘good’ and to set clear and achievable targets.

→  Download the Climate Emergency Design Guide here


27.01.20  Embodied Carbon Primer

This Embodied Carbon Primer offers supplementary guidance to the Climate Emergency Design Guide for those interested in exploring embodied carbon in more detail. There is currently a lack of knowledge in the built environment industry surrounding embodied carbon reduction strategies and calculations. Therefore, the London Energy Transformation Initiative has produced this document to support project teams in designing buildings that deliver ambitious embodied carbon reductions.

→  Download the Embodied Carbon Primer here

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16.12.19  Net Zero One Pager

Industry consensus has been established on the key features of Net Zero Operational Carbon buildings. This new 1-page summary was launched by the London Energy Transformation Initiative (LETI) on 16.12.19 at Feilden Clegg Bradley Studios. It is the result of a very successful industry consultation with more than 330 responses and has been developed in collaboration with the UK Green Building Council (UKGBC) and the Better Building Partnership (BBP).

→  Download the One Pager here

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14.03.19  Consultation on a Definition for Net Zero Carbon

In order to meet our climate change targets all new buildings need to operate at net zero carbon by 2030 with all buildings operating at net zero carbon by 2050. In order for the above statement to be implemented, a robust definition of what net zero carbon means for buildings in the UK needs to be developed. LETI has received feedback from 140 built environment professionals from 78 organisations through an online survey and through a workshop. The findings are summarised in this document.

→  Download the report here

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14.02.18  Draft London Plan Consultation Response

The third ‘Getting to Zero’ publication gets into the detail of LETI’s response to the London Plan consultation. The GLA invited LETI to host a consultation workshop for the London Plan focusing on zero carbon, energy monitoring, the heating hierarchy, demand management and embodied carbon.  The report provides feedback on the wording of the polices, suggestions for Supplementary Planning Guidance (SPG) content and advice for the GLA to help support the policy implementation at borough level.

→  Download the report here

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20.09.17  Proposals for Energy Policy

The second ‘Getting to Zero’ publication outlines the London Energy Transformation Initiative proposals for energy policy. This is a summary of the second phase of the London Energy Transformation Initiative and includes the 4 working group reports on Data Disclosure, New Performance Metrics For Better Outcomes, Decarbonising Energy & Heat and Delivery Mechanisms.

→  Download the report here

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03.07.17  Developing Policy for a Net Zero Capital

The first ‘Getting to Zero’ publication is a summary report of the ‘Let fix London’s broken energy policy’ workshop that was facilitated and organised by Elementa Consulting. This report summarises the outcomes of the workshop and outlines next steps towards developing policy that can enable London to become a Zero Emissions Capital.

→  Download the report here

PLEASE NOTE: LETI graphics in these publications can be used by others in print or online. However, if graphics are used please do provide a photo/ image credit to LETI. In doing so, you help further the reach of LETI's work and help facilitate the transition to a zero carbon future.   

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