Healthy, safe, sustainable buildings – maximising benefits in building retrofit

Key findings of the report

This report provides an overview of how to maximise the benefits in building retrofit to deliver healthier, safer indoor spaces. It supports the government's commitments to transform homes by making them cleaner and cheaper to run through the delivery of the Warm Homes Plan.

The report shows how building retrofit programmes are essential to improving the quality of homes and buildings, meeting national net-zero goals and addressing health inequalities. It presents a range of key factors that will need to be considered including insulation and airtightness, ventilation and air cleaning, and low-carbon heating.

The report concludes with five recommendations for policymakers to embed a systems-based approach to maximise the benefits of retrofit.

This work builds on previous publications from the National Engineering Policy Centre (NEPC) which explored opportunities to embed infection resilience across the built environment.

I feel strongly about the importance of improved health with retrofit schemes. We spend most of our time indoors. We need to turn the challenges we have with indoor environments into opportunities for society such as improved health, lower energy bills, reduced stress on the health service, greater productivity, and lower emissions.

Dr Shaun Fitzgerald OBE FREng, University of Cambridge.

Why do we need to retrofit and what does building retrofit mean?

The UK has set ambitious legal targets for reducing greenhouse gas emissions and achieving net zero by 2050. With the heating and cooling of buildings contributing 17% to national emissions, retrofit schemes are a critical step towards the UK achieving net-zero by 2050 and mitigating the threats of climate change.

To achieve these aims, there is a need to reduce the energy demand of buildings, improve energy efficiency, roll out low carbon heating technologies and scale up renewable energy production.

Retrofit schemes can deliver many of these benefits:

• Structural change: installing insulation, upgrading windows, improving airtightness to reduce heat loss and energy demand, and provision of appropriate ventilation.
• Changes to building services: such as switching to low-carbon heating.
• Monitoring and control tools: Providing more information about user-behaviour to encourage reduction. 

Retrofitting buildings also has the potential to improve the health of occupants and users as well as reducing systemic health inequalities. The report also outlines how to retrofit buildings with a holistic approach to improve health outcomes alongside sustainability.

Recommendations for policymakers

The report makes five key recommendations for retrofit schemes. The recommendations will help embed health outcomes in retrofit programmes; enable specialist training for retrofit professionals and trial digital records for building performance and maintenance. 

1. Health-based outcomes: Embed health-based outcomes in retrofit programmes, supported by public information campaigns.
2. Public buildings assessment: Large-scale assessment of health risks in public buildings to inform retrofit needs.
3. Digital passports for buildings: Trial digital records for building performance and maintenance to support long-term management.
4. Training and skills development: Incorporate health and sustainability into training for retrofit professionals.
5. Research and development: Address knowledge gaps on long-term health impacts of indoor environments and integrate findings into policy and practice.

Explore the recommendations in full

A thermal imaging camera shows heat loss spots around some windows as part of an inspection. Credit: Shutterstock

Retrofitting buildings for health and wellbeing benefits

Indoor environments have a significant impact on the health and wellbeing of occupants – through heat, light, noise or air quality.

The Department for Health and Social Care (DHSC) aims to shift the focus of the NHS from sickness to a preventative approach to tackling ill health. Therefore improving the health of indoor environments is critically important.

When applied well, building retrofit can achieve the following benefits:

Insulation and airtightness

• Improving insulation and airtightness can prevent draughts and heat loss, making it easier to manage comfort and heating. It also mitigates health risks from cold conditions such as hypothermia or respiratory conditions.
• Retrofit can help avoid issues with damp and mould. These conditions, if left untreated, can be harmful to occupants, and in extreme cases, can even be fatal to vulnerable populations.

Ventilation and air cleaning

• When people gather in indoor spaces, stagnant air causes pollutants (such as carbon dioxide and infectious diseases (for example flu and COVID-19)) to build up. Indoor pollution can be controlled through effective ventilation, which can then deliver improved health outcomes. This includes reductions in rates of asthma, coronary heart disease, stroke and lung cancer.
• Respiratory conditions are the fourth most common reason for sickness absence in the labour market, so healthier buildings can contribute to productivity too.

Protection from extreme weather

• Climate change has made extreme weather events like heatwaves more common. Successful retrofit interventions can improve the stability and resilience of buildings, mitigating the risks to occupant health, especially for elderly or vulnerable populations. 
• Retrofit can reduce energy demands for heating. In cold weather, this can also mean reducing the operating costs of central heating systems.
• Retrofit policies typically aim to protect against exposure to severe cold conditions, but there is an opportunity to ensure resilience to extreme weather – both hot and cold.

Conclusions

To develop effective retrofit programmes, a system-based approach is essential. Policymakers and industry partners should work together to define how this approach will function in practice, helping building owners plan for specific needs and advancing these programmes. This should include regulation, standards and accreditation processes.

Government departments and organisations often have overlapping interests and responsibilities related to retrofitting but frequently work in silos. Without comprehensive guidance, retrofit schemes may only meet minimum standards and miss out on potential benefits.

To fully realise the opportunities that retrofit offers, an outcomes-based approach is crucial. This will ensure that building performance supports health, safety, and sustainability throughout its lifespan. Achieving this requires collaboration among policymakers, guidance providers, installers, and building operators to integrate health and wellbeing into central and local retrofit strategies.

Download the report

A person rolls out a bail of fibreglass insulation in a room. Credit: Shutterstock.

Contact us

For further information about this project, or to share evidence on the issue of building retrofit, please contact the Royal Academy of Engineering team: [email protected]

Acknowledgements

Working Group

This work was carried out with a subset of the Infection Resilient Environments Working Group, which included:

Chair: Professor Peter Guthrie OBE FREng

Edith Blennerhassett, Arup

Dr Hywel Davies, Independent advisor

Dr Shaun Fitzgerald FREng, University of Cambridge

Colin Goodwin CEng, FCIBSE, Chartered Institution of Building Services Engineers

Professor Catherine Noakes OBE FREng FIMechE, FIHEEM, University of Leeds

Catch up 

Find out more about healthy, safe, sustainable buildings, by catching up on our critical conversations event: Built environment: visions for greener, healthier buildings.