VOICES | ANNA MAVROGIANNI Housing and hardship Households hit hardest by the cost-of-living crisis are those most likely to live in unhealthy homes. UCLs Professor Anna Mavrogianni considers the relationship between the built environment and health inequalities T here is increasing recognition of the role the built environment plays in peoples health and wellbeing. A wide range of health determinants is contingent on the quality of the built environment, including neighbourhood conditions, green infrastructure, and outdoor and indoor environmental quality. It is expected that health inequalities will be exacerbated by the ongoing costof-living crisis. A hike in energy prices, a reduction in disposable income and low thermal efficiency levels of the housing stock mean almost a quarter of UK households are now facing fuel poverty, with large families, lone parents and pensioner couples most affected. Beyond the impacts of rising fuel costs on health and wellbeing, there are also interactions between building energy efficiency and building services, financial choices, occupant behaviour, indoor air quality (IAQ), and comfort. One example is the increase in mould risk because of reduced heating. English Housing Survey assessments say that damp and mould risk is almost four times higher for the poorer quintile group compared with the wealthiest group.1 Another example is the emerging trend of switching to solid-fuel heating. The rapid rise in domestic burning of solid fuels, such as wood, for heating can cause outdoor and indoor air quality to deteriorate. Currently, there is lack of financial mechanisms to support the installation of energy efficiency measures. According to a recent letter by the Climate Change Committee (CCC), the number of government installations of energy efficiency measures fell from 2.3 million a decade ago to fewer than 100,000 in 2021. While it is imperative we decarbonise our building stock, single-focus policies can potentially lead to unintended consequences if other aspects of building performance are neglected. As buildings become more thermally insulated and airtight in the path towards net zero, unintended ventilation air exchange paths will be diminished. Unless energy efficiency interventions are combined with sufficient means of controlled ventilation, this could lead to air pollutants and heat trapped indoors. A recent BMJ paper called for empirical longitudinal data to be collected in energy efficient buildings, to quantify the effects of low carbon measures on health and inequalities.6 The effects of outdoor air pollution are not equally distributed: it is estimated, for example, that 46% of the most deprived London areas experience NO2 concentrations above the recommended EU limits; thresholds are exceeded in only 2% of the least-deprived areas. Although the distribution of indoor air quality exposures across building types and socioeconomic groups was less understood until recently, research studies have demonstrated that households of low socioeconomic status are exposed to higher levels of indoor air pollutants on average. This may be the result of overcrowding or solid-fuel cooking causing increased particulate matter, or the use of lower-quality consumer products that may emit volatile organic compounds. Lower-income households may also live in lower-quality housing where ventilation systems are not repaired regularly. This summer, the UK experienced an unprecedented 40C heatwave and, across Europe, the hot spell caused more than 20,000 excess deaths. The effects of extreme heat can hit the most vulnerable the hardest. Older people and individuals suffering from ill health are generally most at risk, but social isolation and low income can also limit ones capacity to identify a hazard and reduce exposure. Poorer households may have lower thermal-adaptive capacity, as they may have limited access to cool spaces and be less able to afford to modify their surroundings through retrofit or air conditioning. The potential of natural ventilative cooling may be less in lower-income neighbourhoods, where concerns about crime, noise and traffic-related air pollution may hinder window opening. Although fuel-poverty research and policy generally refer to winter, summer fuel poverty may soon become a significant issue too. A recent CCCcommissioned report by Arup found that the cost of implementing passive cooling measures in existing homes is appreciable. Integrating health, wellbeing and equity with net zero goals and building safety is critical to achieving a healthy and sustainable built environment for all. References 46% of the most deprived London areas experience NO concentrations above recommended EU limits ANNA MAVROGIANNI is professor of sustainable, healthy and equitable built environment at the Bartletts UCL Institute for Environmental Design and Engineering (IEDE) and a member of the CIBSE Health and Wellbeing working group, chaired by Dr Milena Stojkovic (Foster + Partners) and Dr Marcella Ucci (UCL IEDE) 18 April 2023 www.cibsejournal.com Please see this article at www.cibsejournal.com