ADD2296 Urban Heat Island in London

The purpose of Phase 2 project, called, ‘Design to mitigate the contribution of new developments to the urban heat island in London – tools and guidance’, is to enhance the usability of the research, mapping and analysis developed as part of the ‘Heat Risk in London – translational research/modelling/report and guidance’ Phase 1 project. The usability function, in the form of a web tool and guidance, will enable planners and designers to mitigate the contribution of new developments to the urban heat island in London at the planning and assessment stage of new developments.

The focus will be on translating the outputs from Phase 1 into a usable tool and guidance for designers, planners and policy officers to use in a practical way. The Phase 2 output will be simple and easy to use, freely available on the GLA website and will demonstrate its added value over and above existing tools and guidance.

This work seeks to fulfil Policy 8.4.3 from the London Environment Strategy which aims to minimise the risk of new development overheating. This proposes, ‘The London Plan includes policies to minimise the risk of new developments overheating and reduce their impact on the Urban Heat Island (UHI)’. The Environment Strategy further sets out that, ‘The Mayor will also consider the impacts of further densification of London on the UHI and develop guidance on how new developments can be designed to minimise the amount of heat absorbed by the development, which is then released at night, warming the surrounding area.’

This work is distinct from the current guidance provided which focusses on how to mitigate internal heat risk. This project focuses on how to mitigate a development’s wider contribution to the UHI and overheating impacts specifically related to how to mitigate risk to and from the UHI.

Objectives

Understanding how London’s changing demographics, urbanisation, densification and climate change contribute to the UHI and how measures can be put in place in new developments to mitigate that contribution to the UHI and development heat risk.

Understanding UHI risk from existing/baseline site characteristics pre-development.

Understanding UHI risk created by different types of development typologies.

Expected outcome

Provide tailored mitigation measures specific to site risk and typology risk to reduce new development’s contribution to the UHI that are easy for designers, planners and policy officers to understand.

This project stems from the current London Environment Strategy which is informed by a full Integrated Impact assessment which includes consideration of equalities. This project will specifically look to maximise the positive impact on Londoners by reducing the health impacts and health inequalities of overheating risk by providing tailored mitigation measures specific to site risk and typology risk. In this way it is intended that a new development’s contribution to the urban heat island is reduced.

a) Key risks and issues

Delays in undertaking any of the above activities (due to not having budgets and/or contracts in place) could lead to delays in project delivery that could have a negative reputational risk on the mayor.

Mitigation: The timeline and expected cost for all activities have been reviewed. In addition, a risk register will be drawn up for the project to identify and monitor risks.

Staff resources have been identified within the GLA’s Adaptation team to manage and take forward the project.

b) Links to mayoral strategies and priorities

The London Environment Strategy– the design of the policies set out in the strategy will benefit all Londoners, but due to the unequal impacts of heat risk on the most vulnerable Londoners, there is likely to be a positive effect in tacking social and health inequality of this project’s activity.

Assistant Director’s approval is sought for expenditure of £15,000 to deliver the activities associated with the project called, ‘Designing to mitigate the contribution of new developments to the urban heat island in London – tools and guidance’. This will be funded from Environment team’s 2018-19 Cross Cutting budget.