If we make a change to an area where people live, what is the impact on health and how can we value this?
TRUUD is developing a valuation model to help planners, investors and developers understand the health impacts of urban development plans.
We know the environment around us can have a profound effect on health and quality of life, but it can be hard to anticipate the magnitude of this for a specific place, or to compare lots of different health impacts across all the alternative options.
The Health Appraisal of Urban Systems Model (HAUS) quantifies and values the health impacts of different characteristics of the urban environment. These include conditions indoors as well as those around our homes. It features the natural environment (including air pollution and green space), transport, socio-economic factors (such as crime or deprivation), climate change and community infrastructure (such as public transport and access to healthy food).
Dr Eleanor Eaton, University of Bath explains HAUS
How it works
HAUS is driven by changes in the environment which have been shown to have a measurable impact on health.
We take data from our review of published medical studies to produce a bank of impacts, covering a wide range of factors from air pollution to opportunities for walking. We use these to forecast what might happen if one or more of these factors are changed.
The impact of disease is felt by individuals, our NHS and social care providers, through our ability to care for others, through lost work, lost wellbeing and lost life years. HAUS provides a bank of more than 70 unit costs of health, taken from published economic valuation studies and our own research into the costs of ill health.
HAUS is a comparative risk assessment model, which means that it compares levels of risk to health between a baseline and at least one other scenario. It includes evidence on demographics and risk of disease in the modelling, and calculate changes to health in terms of attributable cases of illness and premature life years lost. We then apply the financial impact of these changes into the potential cost to society.
For more information read our briefing note Valuing the ‘external’ social costs of unhealthy urban development (December 2023) and Dr Eleanor Eaton’s presentation ‘Introduction of the HAUS model‘ (July 2024).
What makes HAUS different?
There are some tools available which provide costs on changing specific aspects of a proposed development. These tend to focus on one element, such as green space, or one area of cost, such as costs to individuals.
HAUS allows users to forecast how changes in the indoor or outdoor environment impacts population health, what this costs individuals, agencies and services, and how it compares to other changes.
HAUS will also allow users to connect to the original evidence they need. This could be published medical studies on the association between housing conditions and health, for example.
Importantly, the data includes children, who are often overlooked in modelling.
Developing HAUS
HAUS has informed our spatial planning and urban transport interventions through work with embedded researchers in Bristol and Manchester.
In Bristol local government officers were able to consider land-use trade offs for a large scale regeneration plan and in Manchester HAUS has brought another layer of data into the Streets for All design checklist to help the city’s ambitions for healthier place making. Outside these local applications, we are working with real estate investors to explore how health data could be used to inform their plans for sustainable urban schemes. HAUS is also being explored in our national government intervention for its potential to help improve how we consider health in policy appraisal and strategic planning.
Next steps
The model is still being tested, so it can’t be shared – yet.
We are planning to make a simplified beta version available for anyone who wants to experience the model.
While government and industry testing continues we can take expressions of interest for future collaborations. Get in touch.
Resources
Background
- Short animation introducing the valuation model (2023)
- Briefing note introducing HAUS, its main features and structure: Valuing the ‘external’ social costs of unhealthy urban development (2023)
- Academic article in Frontiers in Public Health providing an in-depth look at the development and specification of HAUS: Developing and testing an environmental economics approach to the valuation and application of urban health externalities (2023)
- Briefing note outlining all the evidence behind the model: Evidence used in the HAUS model (2024)
- Briefing note explaining what HAUS adds to current government appraisal guidance: Adding value to existing government appraisal guidance with HAUS (2024)
Application
Briefing note summarising how HAUS is being applied in the Ministry of Housing, Communities and Local Government: Providing health impact evidence for government appraisals and decision-making (2024)
Briefing note demonstrating how HAUS has been applied to help local government officers in Bristol consider land-use trade offs in a large scale regeneration plan: Using health evidence to influence urban regeneration in Bristol (2024)
HAUS data and evidence
The following health data was sourced from HAUS and other sources to inform series of films illustrating what it is like to live in an unhealthy place.

Overcrowding
- Health risks from overcrowding include intestinal and respiratory infection, and mental ill-health from sleep disturbance.
- In England, approximately 708,000 households are living in overcrowded conditions.
- The saving to the NHS of solving overcrowding in England could be £5 million every year, with a wider societal benefit of £80 million, due to less absence from work, increased productivity, and lower costs to social services and education providers.

Lack of green space / place to play
- Good quality parks and green spaces can help reduce risk of depression, diabetes and weight gain.
- Around 6 million people in the UK do not have access to a park or green space within a 10 minute walk.
- Providing a new park for a neighbourhood of 1,000 people could provide health savings of at least £9 million over 25 years.

Damp and mould
- Damp and mould in the home has been associated with 3.5 times the normal risk of asthma in children, and increased risk of respiratory conditions and asthma attacks in adults.
- Long term, persistent exposure can damage mental health.
- In 2018, 75,000 homes in England were found to have damp problems so serious that they constituted an immediate risk to health and safety.
- Solving serious damp in just one small neighbourhood of 1,000 people could save £7.68 million over 25 years in reduced cases of asthma in children and £2.2 million in reduced respiratory diseases for adults.

Traffic noise
- The World Health Organisation has found that noise could be the second largest environmental risk to health after air pollution.
- Long term traffic noise disrupts sleep for adults and children and causes stress to our bodies, leading to long term chronic illnesses, poor mental health and earlier death.
- Around 40% of adults in England are exposed to traffic noise levels over 50dB (beyond which causes stress).
- Sleep disorders cost each sufferer on average £1,163 per year just in lost wages.
- By reducing noise for one small neighbourhood of 1000 people the savings to society of all related health problems could be £9 million over 25 years.

Air quality
- Air pollution affects people of every age, increasing risk of respiratory disease, cancers, diabetes, heart disease, stroke and Parkinson’s Disease.
- Air pollution in the UK causes between 28,000 and 36,000 deaths every year.
- The value to society of preventing all early deaths related to air pollution in the UK could be £70-90 billion per year.
Get in touch
The HAUS model was designed and built by the team at the Department of Economics at the University of Bath. Contact the lead author, Dr Eleanor Eaton.