Costing the Rush to Build Sick Cities

Urban planning decisions taken years before a home is built already determine much of the health outcome a resident will experience. Housing type, density, access to green space, air quality and noise all shape rates of asthma, obesity, cardiovascular disease and mental ill health. No single part of the housing or planning system carries formal responsibility for these outcomes. 

A five year research programme led by Professor Sarah Ayres, professor of public policy and governance at the University of Bristol, has set out to change that. TRUUD, Tackling Root Causes Upstream of Unhealthy Urban Development, is a transdisciplinary consortium of 50 scholars from six institutions, backed by £6.6 million in funding. The project has worked with central government, mayors, local authorities, developers and real estate investors to trace how health costs accumulate through development decisions, and where those costs land. 

Quantifying the cost of unhealthy places 

At the centre of TRUUD's work is an economic valuation model, developed from an earlier Wellcome funded project led by Bristol's Dan Black with economists from the University of Bath. The model, now known as HAUS, the Health Appraisal of Urban Systems, links features of the built environment to health outcomes, prices the resulting ill health, and identifies where those costs are ultimately borne. 

The pathways it maps are specific. Noise pollution has been linked to ADHD in children, school disruption and cost to the education sector. Air pollution contributes to respiratory illness, lost working days and cost to employers, the Treasury and the pensions system. A single change to a housing scheme can prevent a measurable number of childhood asthma cases, and the cumulative cost of even a small number spirals across a thirty year life course. 

Into government guidance 

TRUUD's model has now been incorporated into the MHCLG Appraisal Guide, in a new section covering the assessment of health impacts of urban design. This is the guidance government departments use to test whether spending represents value for money, and for the first time, a health return on investment can be set against other criteria when a scheme is assessed for public funding. 

The model was stress tested with government and peer reviewed, with input from the Department for Health and Social Care on minimum quality thresholds. TRUUD describes the resulting figures as conservative, built on established economic consensus on the cost of death, discomfort, pain and treatment, rather than inflated projections. 

A remit nobody holds 

TRUUD's central finding is structural. Housing, transport and infrastructure teams across government and local authorities operate to short term, siloed remits, and health is not one of them. One senior official at the Ministry of Housing, Communities and Local Government put it plainly to researchers, the department builds houses, it does not deal with asthma cases. 

This absence of ownership means health is routinely priced out of decisions long before residents are affected. TRUUD has built a cross Whitehall group spanning MHCLG, Treasury, Transport, the Department for Environment, Food and Rural Affairs, and the Department for Health and Social Care, on the basis that guidance agreed within MHCLG alone will not gain traction without buy in from departments that hold the money. 

The limits of devolution 

Elected mayors and strategic authorities have some jurisdiction over housing, transport and infrastructure, but not enough alone to reset the incentives shaping development. Change relies on hard power, the statutory levers mayors can pull directly, combined with soft power, persuading developers and other local actors to act differently. 

A public health duty is due to reach mayors and strategic authorities through the devolution agenda, which TRUUD identifies as a genuine opportunity. Local and regional bodies currently operate with constrained budgets and variable technical capacity, and will need funding and appraisal tools if the duty is to translate into different decisions on the ground. 

Where assessments and delivery fall short 

Health impact assessments already exist within planning, but TRUUD's review found they are not applied systematically, and are often used poorly where they are. Compiling the evidence and economic data a rigorous assessment needs sits beyond the capacity of most planning teams working scheme by scheme, which HAUS is intended to supply as a ready assembled resource rather than a duplicate process. 

The clearest test of that ambition sits within the government's New Towns programme. Danny Fellows, a senior economist at MHCLG leading the New Towns team, has worked with TRUUD since the HAUS model's early development, and is now applying health thinking to New Towns schemes alongside Homes England, which has committed significant time to refining the model for large scale housing development. 

Pressure to build quickly, cheaply and at volume can crowd out long term health outcomes, producing homes that later require retrofitting for a changing climate. TRUUD's position is that volume and health are not opposing objectives, provided health evidence is built into decisions from the outset rather than added once a scheme is already committed. 

From a Healthy Homes Hub perspective, this shifts the basis on which investment in housing quality is judged. Where the health return on a design choice, a retrofit measure or a development decision can be quantified against its capital cost, health becomes a measurable input alongside the other criteria that already govern spending decisions.  

Practical steps for housing providers 

• Review how health outcomes are currently weighted, if at all, in business cases for new development and retrofit programmes, and identify where a model such as HAUS could be applied. 

• Engage with regional devolution deals to understand how an incoming public health duty for mayors and strategic authorities might affect local planning and investment decisions. 

• Map existing health impact assessment practice against the MHCLG Appraisal Guide to identify gaps in application, rather than assuming a policy commitment is being carried out consistently: https://www.gov.uk/government/publications/the-mhclg-appraisal-guide 

• Build relationships with local public health teams and combined authorities early in scheme development, before decisions on design and location are finalised. 

• Treat the absence of a formal health remit as an organisational risk rather than a reason for inaction, and identify who within the organisation is accountable for health outcomes in housing decisions. 

• Read more on TRUUD's research and its consortium partners: https://www.bristol.ac.uk/population-health-sciences/projects/truud/  

• Request access to the HAUS model to see how it values health impacts: https://www.bath.ac.uk/projects/the-haus-health-appraisal-of-urban-systems-model/  

Image credit: Adobe Stock