The Bartlett


A healthy, low-carbon built environment

Research into the effect of the built environment on energy use and health has contributed to a shift in the understanding of the possible health impacts of carbon mitigation measures.

The Bartlett’s work in this area, in collaboration with our partners, has influenced the development of guidance and regulations in this area.

Urban heat islands

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 minimising summer cooling energy demand and health risks, while retaining decreased winter heating demands and health risks due to reduced exposure to cold.

The Greater London Authority (GLA) drew on this work in its guidance relating to UHIs. The Mayor of London’s climate change adaptation strategy (Managing Risks and Increasing Resilience, 2011) also 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. This was included in the 8th edition of their Environmental Guide, which is an important reference source for their 19,000+ members.

Relative humidity and mould growth

Another strand of the group’s research 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 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 changes reflected specific recommendations such as the need to respond appropriately to the transient nature of mould growth.

The research provided policymakers with novel recommendations about the 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. It improves safety and allows house builders to demonstrate the legal requirement for compliance with the Building Regulations.

The World Health Organization (WHO) also invited UCL researchers to provide expert advice on humidity and mould growth. This informed important new WHO mould documents published in 2010.

This guidance provides policy-related recommendations and identifies potential ways for authorities to prevent, reduce or mitigate exposure to dampness and mould.

Evaluation tools

The UCL research has also helped to develop new evaluation tools, with modelling techniques being used. This is 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. It also calculates the monetary value of the health impact associated with energy efficiency changes in houses in the UK.

HIDEEM was used to calculate the value of health benefits of installing solid wall insulation in all properties in England. The DECC determined that this would give a total improvement in people’s health of £3.5–5 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. The DECC’s Fuel Poverty Framework (2013) notes, “for this reason, we should continue to prioritise vulnerable poor households for support”.