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The London Energy Transformation Initiative (LETI) is a network of over 250 built environment professionals that are working together to put London on the path to a zero carbon future. The voluntary group is made up of developers, engineers, housing associations, architects, planners, academics, sustainability professionals, contractors and facilities managers, with support and input provided by the GLA and London boroughs. Elementa Consulting have initiated and coordinated LETI as they were frustrated that the current energy policy in London wasn’t driving design solutions that encouraged long term carbon emissions reduction. LETI was established to work collaboratively to put together evidence-based recommendations for two pieces of policy – the new London Environment Strategy and the rewrite of the London Plan.

LETI acknowledges that global temperature rise needs to be kept below 1.5 degrees to avoid catastrophic climate change. To achieve this, all new buildings must operate at Net Zero Carbon by 2030 and existing buildings by 2050.  As a global city, London has a responsibility to help lead the transition to a low carbon future.


LETI believes that current energy policy relating to carbon emissions in buildings in London will not deliver Net Zero Carbon for new buildings by 2030 and therefore recommends the following proposals be implemented in policy to get London on the right trajectory. These proposals will help in the delivery of buildings that are more energy efficient, lower carbon and less expensive to occupy.

  • Revise the London Plan Energy Strategy Targets

  • Heat Networks

  • Offset payments

  • Energy Use Disclosure


LETI Proposal 1- Revise the London Plan Energy Strategy Targets

The current planning targets, based on using Building Regulations Part L compliance tools and percentage carbon emissions improvements over a notional building, encourage a culture of false reporting and thus do not lead to best practice design and performance. It is proposed that the London Plan energy strategy shall introduce a kWh/m2 site energy use target, as well as introducing a fabric energy efficiency target, onsite renewable energy generation and a peak demand reduction method statement. 

LETI Proposal 3- Offset payments

The current carbon offset policy does not deliver zero carbon buildings. The Mayor should provide guidance for the boroughs on the implementation of the carbon offset policy and require annual reporting relating to offset funds by London boroughs. The offset payment calculation methodology should be updated to include total building energy use, regulated and unregulated energy with staged payments to the boroughs. The cost of a tonne of carbon should be set at a level that incentivises on-site carbon emission reduction and reviewed regularly.

LETI Proposal 2- Heat Networks

The priority must be to ensure that policy drives decision-making that delivers long term carbon emission reductions in a way that gives the designers flexibility to incorporate engineering strategies that are appropriate to the building use. Resilience should be encouraged with systems that are technology neutral and can adapt to future technologies and building uses. All heat networks and communal heating systems should be required to provide a strategic district energy local plan that includes a Zero Carbon transition plan. All new developments should follow the ‘delivering low carbon heat’ hierarchy that prioritises the use of energy sharing networks to reduce load and energy storage (batteries and thermal stores) to reduce peak demand.



LETI Proposal 4- Energy Use Disclosure

Disclosure of building energy use is a central component underpinning progress in reducing carbon emissions and running costs. It is proposed that a new ‘Be Seen’ stage of the energy hierarchy be introduced such that all new buildings disclosed their energy use annually in kWh/m2, broken down by building type in the development, fuel type and by regulated and unregulated use. Energy consumption would be displayed transparently on an online platform along with the predicted energy performance from the energy assessment. This platform can be used to show how developments and buildings are performing. The power to mandate the use of Display Energy Certificates (DECS) for all buildings should be devolved to the Mayor so that energy use disclosure in existing buildings can be mandated, in the meantime it should be incentivised.



Development of proposals

The LETI energy policy proposals have been developed over the last 6 months. In May 2017, over 100 built environment professionals came together in a workshop facilitated by Elementa Consulting. During the workshop participants worked at 10 tables, each tackling a different theme. Four priorities emerged; data disclosure, better performance metrics, decarbonising heating & energy and delivery mechanisms. 





Next 4 working groups were established, one around each priority. The working groups established a set of recommendations for energy policy. These recommendations were merged together by the LETI taskforce who have published a set of proposals for energy policy.

Next Steps

The next step is to show the Mayor and the GLA that these energy policy proposals are supported by industry. To that end, LETI are gathering signatories on behalf of individuals and organisations