Research Impact


A healthy, low-carbon built environment

Construction workers looking at plans

12 December 2014


Research into the effect of the built environment on energy use and health has contributed to a fundamental shift in global understanding of the possible health impacts of carbon mitigation measures. UCL's work in this area, in collaboration with our partners, has influenced the development of guidance and regulations at regional, national and international levels.

One aspect of the UCL research focused on the health impacts of urban heat islands (UHIs) and overheating in dwellings. It produced new guidance for measures to minimise summer cooling energy demand and health risks, while retaining lower winter heating demands and decreased winter health risks due to reduced exposure to cold. The Greater London Authority (GLA) drew on this work in its guidance relating to UHIs, and the mayor of London's climate change adaptation strategy (Managing Risks and Increasing Resilience, 2011) details plans to tackle overheating in London. The research has supported the GLA's development of better evidence-based policies to optimise its adaptation and mitigation measures, and to target limited funding as effectively as possible.

Elsewhere, the Chartered Institution of Building Services Engineers (CIBSE) used the research in its development of UHI guidance to be included in the 8th edition of their Environmental Guide, which is an important reference source for the 19,000+ members of CIBSE.

Another strand of the group's research, into relative humidity and its effect on mould growth, has led to changes in the Building Regulations for England and Wales. The work looked at how to reconcile the need for sufficient ventilation to minimise damaging mould growth in homes with the desire to minimise airflow in order to reduce energy use and carbon emissions.

In 2010, the moisture criteria guidelines (ADF 2010) for the control of mould growth in dwellings were amended. The fundamental changes made reflected specific recommendations such as the need to recognise and respond appropriately to the transient nature of mould growth. The research provided policymakers with novel recommendations about the daily, weekly and monthly maximum average levels of relative humidity that should be permissible in dwellings. Every dwelling constructed in England and Wales since 2010 has been subject to ADF 2010; from 2011 to 2012, this amounted to more than 230,000 households. Following the guidance improves the safety of dwellings and allows house builders to demonstrate the legal requirement for compliance with the Building Regulations.

The World Health Organization (WHO) invited UCL researchers to provide expert advice on humidity and mould growth, which informed important new WHO mould documents published in 2010. This guidance provides policy-related recommendations and identifies potential ways for international, national and local authorities to prevent, reduce or mitigate exposure to dampness and mould.

The UCL research has also helped to develop new evaluation tools, with modelling techniques being used, in collaboration with colleagues from the London School of Hygiene and Tropical Medicine, to develop the novel Health Impacts of Domestic Energy Efficiency Measures (HIDEEM) tool for the UK Department of Energy and Climate Change (DECC). This included the construction of micro-environmental stock models to quantify indoor environmental conditions and calculate the monetary value of the health impact associated with energy efficiency changes in houses in Great Britain.

Using HIDEEM to calculate the value of health benefits of installing solid wall insulation in all properties in England, DECC determined that this would give a total improvement in people's health of £3.5 to £5 billion over the lifetime of the measures. DECC's modelling work using HIDEEM also suggests there are substantial health-related costs associated with cold homes, and DECC's Fuel Poverty Framework (2013) notes "for this reason, we should continue to prioritise vulnerable poor households for support".

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