Development design has a significant collective influence on population-level health and wellbeing, explains Mark Cope
There is plenty of evidence that the design of a new development shapes the conditions in the built environment which are necessary for sustaining health and wellbeing. Unfavourable social, environmental and economic conditions lead to behavioural risks and disease patterns at the population scale that account for around half of all variation in health outcomes.
Figure 1: Key considerations when designing new development for better health outcomes.
Quality of the built environment
The link between health and the quality of the built environment is clear. Shelter is a basic requirement for sustaining life, but poor-quality buildings can create health problems of their own. The risk of developing a respiratory condition is higher in cold, damp accommodation, and is greatly reduced in buildings that are warm and energy efficient.
Indoor air quality issues can also exacerbate chronic health problems such as asthma and chronic obstructive pulmonary disease. Indoor pollutant sources include cooking, heating and smoking, but most indoor air quality issues originate in outdoor air pollution, which becomes concentrated inside. Road traffic emissions and tyre wear are the main causes of poor air quality in urban areas. Ventilation design in buildings can help to control the accumulation of these pollutants, and also mitigates overheating.
Overheating in buildings can be a problem for health, particularly for older people who are more susceptible to the effects of heat stress. There are approximately 2,000 heat-related deaths per year in England and Wales. However, the risk of overheating is predicted to increase with climate change, with heat-related deaths in England and Wales projected to rise to more than 7,000 per year by the 2050s. A growing and ageing population are also thought to be contributing factors.
Other sources of pollution also have an impact. The effects of noise pollution are often described in terms of annoyance, but excessive noise can harm both mental and physical health, causing anxiety, high blood pressure and changes in social behaviour. Noise disturbance is most common in poorly insulated high-density accommodation. Road, rail and air transportation, and mechanical plants such as construction equipment and air conditioning units, are also sources of noise. In contrast, natural soundscapes such as flowing water, breaking waves, rustling trees and singing birds have a positive impact.
Exposure to natural daylight and sunlight also has mental health and wellbeing benefits, which are mainly associated with entrainment of the body’s circadian rhythm. Moderate levels of sunlight also provide a source of vitamin D, which protects against a range of diseases, and is most easily be obtained during short periods of outdoor exposure. However, overexposure of skin to ultraviolet radiation from sunlight can also create health problems, associated with sunburn and increased risk of skin cancers.
Overlapping networks within a community reinforce a sense of belonging that supports mental wellbeing. Within community networks, social capital refers to facilities that enable people to mutually co-operate, such as local schools, shops, pubs, indoor social spaces and outdoor green spaces. Walking to a community facility greatly increases the chance that a person will meet other members, providing an opportunity for social contact.
Where factors reduce the likelihood of people choosing to walk, there are fewer social interactions. For example, streets with higher levels of traffic have a greater sense of insecurity and lower levels of social interaction. Community severance is also a problem if high volumes of road traffic pass through a neighbourhood with inadequate crossing provision, resulting in real and perceived safety issues. Pedestrian and cyclist accessibility is improved by limiting vehicle speeds to below 25 miles per hour and providing traffic calming measures such as roundabouts and speed humps.
Social segregation occurs when inequalities exacerbate health inequalities – for example, where income deprivation influences the accessibility of local services such as shops, amenities and cash machines. Similarly, where housing is limited or in high demand, house prices can become disproportionately high in relation to income, resulting in the exclusion of those on low incomes. Health inequalities are exacerbated when the income-deprived have difficulty finding affordable housing in locations that are suitable for their needs.
There is a relationship between crime or fear of crime on physical and psychological health. Fear of crime makes people less likely to leave their home, use public spaces or public transport, and less likely to have chance social interactions with others. Provision of a range of mixed land uses and affordability of housing types is associated with improved safety perceptions in neighbourhoods. Similarly, urban design features such as street lighting and the installation of CCTV are associated with reduced fear of crime.
Opportunities for healthy lifestyle choices
Access to safe and well-maintained green spaces boosts physical activity, mental wellbeing, social interactions and community cohesion. It provides relief from stress, and reduces blood pressure and cholesterol levels. In built environments, when located close to people’s homes or workplaces, green space has a positive influence on activity levels, providing the best opportunity for walking or cycling.
‘Active travel’ refers to journeys taken on foot or by bicycle that are necessary for practical purposes, such as travelling to school or work. It is associated with numerous health benefits, as it involves physical activity and provides greater opportunities for social interactions. However, walking journeys have declined with the growth of habitual car use, and more sedentary lifestyles are associated with weight gain and increased health risks in the general population.
Distance is the strongest predictor of active travel. Compact neighbourhoods with higher density and connectivity, and a diverse range of land uses, are generally more conducive to active travel. Perceived safety risk is another barrier to active travel, and provision of cycle paths and street lighting increases the number of walking and cycling trips undertaken.
Poor diet is another factor associated with weight gain with associated health risks, although weight gain is largely a factor of a sedentary lifestyle. For example, access to shops locally can encourage exercise via active travel, and opportunities for food production locally, such as growing fruit and vegetables, can encourage exercise outdoors and improved attitudes towards diet.
Significant self-production of food is dependent on the availability of open space, which is often limited in built up areas. High-density housing and housing with small gardens are not conducive to self-production of food. Allotments, community gardens or orchards and local collectives provide opportunities for local food production, as well as community interaction, social networking and better mental wellbeing.
The condition of the natural environment
Climate change is the greatest threat to global health, impacting disease patterns, food security, water pollution, sanitation and extreme weather – all of which will pose challenges if we are to maintain a healthy built environment. Furthermore, multiple climate and non-climate hazards sometimes coincide, exacerbating impacts; for example, heatwaves in cities exacerbate air pollution levels.
The Intergovernmental Panel on Climate Change has said that improving the resilience and healthiness of built environments should involve mitigating the causes of climate change. For example, an optimised urban form with higher density, pedestrian connectivity and a diverse range of land uses encourages active travel, cuts vehicle-related greenhouse gas emissions and reduces associated air quality impacts. However, the feasibility and effectiveness of climate change mitigation and adaptation in the built environment also requires co-ordination between physical, social and natural infrastructure.
Natural infrastructure or ecosystem services are the range of ecological resources, processes and sinks required to provide the balanced and stable conditions necessary for life on earth. These include provisioning services, such as food and water; regulating services, such as flood and disease control; cultural services, such as spiritual, recreational and cultural benefits; and supporting or provisioning services, such as nutrient cycling. Use of ecosystem services must contribute to human health without destabilising the ecosystems upon which we rely. These services can be safeguarded in new development though the creation and management of green and blue infrastructure.
Green infrastructure refers to both multifunctional green spaces and green spaces that allow ecological species to leapfrog between habitats, creating a network. For example, rows of street trees provide habitat and connectivity to other habitats, but also can add aesthetic value to an urban area and thus encourage active travel, remove air pollutants from the atmosphere, and reduce wind microclimate and urban heat island effects. Other examples of green infrastructure include wildlife reserves, urban woodland and orchards, river corridors and flood plains, public parks and gardens, green roofs and green walls.
Blue infrastructure refers to multifunctional spaces with an emphasis on water quality, navigation or flood management. Blue infrastructure can also be useful in response to climate change resilience and adaptation responses, and in the management or urban heat island effects. At the project scale, sensitive management of water principally concerns avoiding ‘end-of-pipe’ design solutions for water management, including sustainable urban drainage systems such as soakaways, swales, permeable surfaces, planting systems, vegetation cover and wetland habitats.
Human health relies on a high-quality built environment, opportunities for community networks to develop and exist, individuals making healthy lifestyle choices, and the overriding condition of the natural environment. In isolation, individual design decisions on new developments have only a limited capacity to influence health. However, when considered collectively and in combination, such design measures are key to shaping better health outcomes at the population scale.
The evidence base used to inform this article has been summarised from a review of the following principal information sources: City of Well-being: A radical guide to planning (Barton, 2017), Spatial Planning for Health: An evidence resource for planning and designing healthier places (PHE, 2017), The Marmot Review (Marmot, 2010, 2020) and Climate Change 2022: Impacts, Adaptation and Vulnerability (IPCC, 2022).
Mark Cope, MIEMA CEnv, is an associate at Hoare Lea, specialising in environmental impact assessment.