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LETI Declaration

Aim of the LETI Declaration

To support London delivering operational zero carbon buildings 

What is the LETI Declaration?

The LETI declaration is a simple form that is appended to energy statements, and seeks to reward the efforts applicants make towards energy efficiency, low carbon heat and low carbon electricity. It is not an additional set of requirements but simply provides information which could better inform the client, the local authority and all stakeholders. Using it leads to a focus on outcomes, to deliver better buildings.

The Standard LETI Declaration contains specific questions that act as pointers and prompts regarding predicted energy consumption and carbon emissions, carbon content of heat, low carbon electricity, energy bills, data disclosure, lifecycle carbon and air quality.

A specific declaration for air-conditioned offices has also been developed, that additionally includes questions around solar gain, free cooling, lighting and HVAC controls; as well as Design for Performance guidance including contractual arrangements for performance verification and disclosure, operational commitments and enhanced modelling.

Download the LETI Declaration
Download the declaration
Why is the LETI Declaration needed?
Why is the Declaration needed?

To help London play its part in avoiding the most devastating effects of climate change, the London Energy Transformation Initiative (LETI) believes that all new buildings must operate at net zero carbon by 2030. This means we only have a few years to improve the way we design and construct buildings.

The draft London Plan has made some big steps in the right direction by introducing energy use disclosure, zero emission plans, enhanced fabric efficiency, minimising peak demand and approaches to decarbonising heating. In order to meet our targets it is crucial that industry builds upon this to be able to deliver operational net zero carbon buildings. 

What is the LETI Declaration for?
  • providing a platform to recognise developments that consider metrics beyond the London Plan; this includes the predicted energy consumption of the development in kWh/m2

  • providing transparent information for all stakeholders

  • addressing the performance gap by encouraging more robust prediction of energy consumption

  • promoting and rewarding new aspects of the draft London Plan before its enforcement in 2019

  • forming an evidence base for the GLA reflecting the industry’s direction of travel

  • providing a database of submissions to create benchmarks

  • providing a good practice guide and prompt for design teams

What is the Declaration for?
Who should complete the Declaration?
Who should complete the LETI Declaration and when?
  • The LETI declaration is normally completed by the consultants who are carrying out the energy statement.

  • Most new developments can complete the Standard LETI Declaration, no matter what size, location or energy performance aspirations.

  • Fully air-conditioned office buildings over 5,000m2 net lettable area and where Part L would require use of a dynamic simulation model rather than SBEM are encouraged to complete the Air-conditioned offices Declaration.

  • A LETI Declaration would typically be completed pre-planning, and a PDF version appended to the energy statement submitted at planning stage, and the respective excel spreadsheet is submitted to LETI.

How will the submitted Declarations be used?
How will the submitted LETI Declarations be used?
  • To understand how much the LETI declaration is being used and implemented

  • To create benchmarks

  • In the future, applicants will be given the opportunity to submit in-use data. This is crucially important to address the current performance gap

  • Data will be anonymised and open source – and can be requested by any non- profit organisation as long as it is used to support the development of operational net zero developments

  • Data collected will not be used for commercial purposes

  • Helps to create the evidence base required to drive the direction of future policy in London and the UK

How was the LETI declaration developed?
How was the Declaration developed?

Over the last year LETI brought together diverse construction industry professionals to put together proposals for changes to energy policy in London. We had a hugely successful year, and many of our recommendations were included in the draft London Plan including; energy use disclosure, zero emission plans, enhanced fabric efficiency, minimising peak demand and approaches to decarbonising heating.

In 2018, LETI’s new is focus is implementing zero emissions principles across the London design and construction sector. To achieve this LETI established the ‘LETI Leading by Example’ workstream made up of over 30 built environment professionals to develop the LETI Declaration.  The LETI Declaration is based on industry best practice such as the Passivhaus standard, Design for Performance, NABERS and Vancouver’s Zero Emissions Building Strategy and the learning from the last year of LETI’s work.

Getting Involved- LETI Declaration Pledge
Getting Involved

The LETI declaration is born out of the enthusiastic industry wide support for the work of LETI so far. Over the last year LETI has supported the London Plan taking some big steps in the right direction by introducing energy use disclosure, zero emission plans, enhanced fabric efficiency, minimising peak demand and approaches to decarbonising heating. However, policy only represents a minimum standard. In order to meet our targets, it is crucial that industry leads by example and builds upon the changes in the draft London Plan to be able to deliver operational net zero carbon buildings. 

LETI has developed a tool to help us achieve this. In order to create real change we now need you to commit to implementing the declaration and build momentum behind the LETI movement.

Please get involved and show your commitment to a zero carbon London by pledging to implement the LETI declaration over the next 12 months.


Furthermore, built environment professionals that are not directly involved in energy strategy submissions can also help by committing to advocate implementing the LETI declaration on projects that they are involved in.

The intention is that the LETI declaration is amended and further developed every 6 months, and specific declarations may be developed for more building types. There is an opportunity to join the group that manages this within the pledge form below.

If you have any questions about the LETI declaration please email 

LETI Declaration Pledge
LETI Declaration pledge
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