Energy and Managing Heat Risk in the London Plan 2021

The Greater London Authority (GLA) has published The London Plan 2021. The Plan sets out a framework for how London will develop over the next 20-25 years so that those who live in, work in, and visit London have the best experience possible.

Individual London Boroughs’ local plans must be in “general conformity” with the Plan, ensuring that the planning system in London operates in a joined-up way and reflects the overall strategy for how London can develop sustainably.

As part of the statutory development plan for the Capital City, policies outlined in the London Plan should inform planning decisions. However, at over 500 pages long, the document is a lot to sink your teeth into. As a business, we’re most interested in Chapter 9: Sustainable Infrastructure. In this article, we’ll talk about the key things within the plan we can potentially help you with.

Within the updated London Plan, there is a strong emphasis on topics such as sustainability, energy usage, carbon emissions, air quality and managing heat risks. Existing rules have been tightened and new ones have been introduced. Whilst some authorities have already been using the guidelines since the draft of the Plan was published, other councils will now be required to adhere to the guidelines.

We regularly carry out work in London and provide a range of services that will help you comply with the updated guidelines.


The London Plan 2021 introduces the country’s strictest targets for meeting low energy and carbon emissions standards. Developments must reduce greenhouse emissions in operation and minimise both annual and peak energy demand. The document makes it clear that the carbon emissions guidelines in the Building Regulations don’t go far enough and sets out a requirement for a minimum onsite reduction of at least 35% beyond Building Regulations for major developments.

The Plan has set out an “Energy Hierarchy” which developers must use in order to reach the net zero carbon targets.

The hierarchy is as follows:

  • Be lean: use less energy and manage demand during operation
  • Be clean: exploit local energy resources (such as secondary heat) and supply energy efficiently and cleanly
  • Be green: maximise opportunities for renewable energy by producing, storing and using renewable energy onsite
  • Be seen: Monitor, verify and report on energy performance

All major planning applications require an Energy Statement which outlines how the development will meet the energy policies in the London Plan. This includes how the proposals will meet the net zero carbon target and how they will apply the energy hierarchy to do so.

The “Be Seen” element of the energy hierarchy aims to bridge the gap between expected performance and actual energy usage. Buildings will need to be monitored post-construction to assess how well they are performing. Displaying a Display Energy Certificate (DEC) is one way of doing this.

Developers will also be expected to maximise opportunities for onsite electricity and heat production from solar technologies (PV and thermal) and use innovative building materials and smart technologies.

The GLA has said that achieving BREEAM energy credits can help demonstrate that energy efficiency targets have been met and Boroughs are actively encouraged to include BREEAM targets in their local plans where applicable.

Managing Heat Risk

New legislation to tackle heat risks is expected to be launched in England later this year so it’s no surprise heat risks have their own section in the London Plan. Due to climate change, the Capital is already experiencing higher than historic average temperatures and more severe hot weather events. This means that managing heat risks within new developments is only growing in importance.

The Plan has set very high standards to avoid the problem of uncomfortably hot buildings in the summer. Development proposals must minimise adverse impacts on the urban heat island through design, layout, orientation, materials and the incorporation of green infrastructure. Plans should also demonstrate how they intend to reduce the potential for internal overheating and minimise reliance on air conditioning systems.

An air cooling hierarchy has been laid out:

  • Reduce the amount of heat entering a building through orientation, shading, high albedo materials, fenestration, insulation and the provision of green infrastructure
  • Minimise internal heat generation through energy efficient design
  • Manage the heat within the building through exposed internal thermal mass and high ceilings
  • Provide passive ventilation
  • Provide mechanical ventilation
  • Provide active cooling systems

The Chartered Institute of Building Services Engineers (CIBSE) has produced guidance on assessing and mitigating heat risk in new developments. We provide Thermal Modelling designed to help with this, including TM 59 for domestic buildings, TM 52 for non-domestic developments and TM 49: Design Summer Years for London (residential only).


The London Mayor is committed to the city becoming zero-carbon and there are stringent measures in place designed to make this goal achievable. The Plan delivers an increased focus on carbon emission-reducing, environmentally friendly measures such as high levels of insulation, environmentally sensible designs, high efficiency lighting and ventilation systems.

It is important to be aware of the Plan and ensure you use building compliance services that take the Plan into account.

There may be further updates to the London Plan in the future. We’ll be keeping an eye out for these and updating our clients when necessary.

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