Housing Sector Briefing

About this document

Findings from the third UK Climate Change Risk Assessment (CCRA3) Evidence Report 2021

This briefing summarises how housing has been assessed in the latest UK Climate Change Risk Assessment (CCRA) Technical Report, and what types of action to adapt to climate change risks and opportunities would be beneficial in the next five years.

This publication is available in PDF format at the end of the page >

Key messages

• The impacts of climate change that affect housing directly, or the occupants within homes, are increasing in frequency and severity over time.
• People are at risk of overheating in their homes. This risk is also already classed as high magnitude as there are an estimated 2,000 heat-related deaths per year, which could more than triple by the 2050s. 
• Household heating demand in the winter is very likely to decrease due to warmer winters, and cooling demand is likely to increase in hotter summers if air conditioning uptake increases. These changes may alter the pattern of peak electricity demand for energy companies. 
• Flooding is already a severe risk to UK housing, and is projected to increase with climate change. Flooded homes can cause long-term and severe impacts on mental health and wellbeing, alongside the obvious damage to property. This risk is already high magnitude with 1.9 million people across all areas of the UK exposed to frequent flooding from either river, coastal or surface water flooding, and is projected to increase even further in the absence of higher levels of adaptation.
• Building fabric can be affected by damp due to flooding and intense rain, structural damage due to high winds and subsidence caused by drought. These cause harm to occupant health and wellbeing and create repair costs for homeowners. 
• A higher incidence of water scarcity in the future could increase interruptions of housing water supplies, especially for private water supplies. This in turn could cause health, social and economic impacts, particularly for vulnerable households.
• Over the next five years, more action has been identified as being needed to keep pace with the rising risks facing UK housing. Strategic research is also necessary to better understand the impacts on housing and how to prepare the housing stock. 

Risks, opportunities, and benefits of further action

Average UK wide scores

• 

  H1. Risks to health and wellbeing from high temperatures

  More action needed

  Read more

• 

  H3. Risks to people, communities and buildings from flooding

  More action needed

  Read more

• 

  H5. Risks to building fabric from moisture, wind and driving rain

  Further investigation

  Read more

• 

  H10. Risk to water quality and household water supply

  Further investigation

  Read more

• 

  H6. Risks and opportunities from summer and winter household energy demand

  More action needed

  Read more

• 

  H7. Risks to health and wellbeing from changes in air quality

  Further investigation

  Read more

1. Risks to health and wellbeing from high temperatures (H1)

Higher summer temperatures and more heatwave events are a risk to population health and wellbeing across the UK.

Currently, the risk of a ‘2018 type’ summer has already increased to around a 10-20% probability in any one year, and this will almost certainly increase to 50% by 2050.

During the 2020 summer heatwave, over ~2,500 heat-related deaths were recorded in England; the highest number recorded since 2003.

The population spends around 90% of each day indoors on average, and there is good evidence that around 20% of homes already overheat even outside of heatwave events. The risks of heat-related deaths are projected to triple by the 2050s without additional adaptation (high magnitude now and in the future). While south-east England tends to experience the highest summer temperatures, people living further north have lower temperature thresholds at which they experience health effects and are therefore also vulnerable.

There is evidence that new homes designed to higher energy efficiency ratings without adequate ventilation are more likely to experience overheating if not considered appropriately.

Beneficial actions in the next five years include:

• Improved building regulations and building design that consider overheating among other aspects of building safety to reduce the risk in new and existing homes undergoing refurbishment.
• Decarbonisation strategies for housing would benefit from being combined with actions to avoid overheating.
• Increase and improve the guidance and incentives to address overheating in existing homes through retrofitting, which is likely to be cheaper if done alongside other improvements to housing to boost energy efficiency and resilience to flooding and damp.
• Implementing green infrastructure, which has the potential to reduce urban temperatures along with delivering other benefits around air pollution and flood alleviation.
• Research conducted to support the risk assessment suggests there is a need to improve public education of the risks from extreme heat and what measures are available to householders to help to lower their risk.

Further details on this risk: Health, Communities and Built Environment Technical Chapter, risk H1

2. Risks to people, communities and buildings from flooding (H3)

The risk of flooding to people, communities and buildings is one of the most severe climate hazards for the population, both now and in the future.

Approximately 1.9 million people across the UK are currently living in areas at significant risk flooding from either river, coastal or surface water flooding. This number could double as early as the 2050s.

Flooding has profound impacts on the people who experience it. As well as a small number of annual deaths or injuries, there is growing evidence of long-term and severe impacts on mental health and wellbeing from flooding; damage to property including the upheaval and financial implications of cleaning up; disrupted access to employment, education, health services and wider facilities; and illness from water-borne pathogens or chemical contaminants arising from floods.

The magnitude of risk is classified as high now and in future for all four countries.

Further details on this risk: Health, Communities and Built Environment Technical Chapter, risk H3

Beneficial actions in the next five years include:

• Continuing the shift to a portfolio approach to managing flood risk; including hard defences but also other adaptation actions such as property-level resilience, natural flood management and insurance.
• Working across the UK nations and widely sharing outcomes from case study examples and initiatives, such as the Flood and Coastal Resilience Innovation programme in England, to enable a more integrated approach and more fuller public engagement.
• Increase investment in socially vulnerable areas and introduce new metrics focused on reducing social vulnerability to flooding to help further mitigate the social costs of flooding.
• Understand how new developments built in at-risk areas are being made safe and resilient, for all new properties in high risk locations. This information should be publicly available by development, and should include whether properties are being protected by flood defences and property flood resilience.
• There is a strong argument for greater enforcement on Sustainable Drainage Systems (SuDS) which will also help to reduce flood risk but also help to achieve biodiversity net gain in new developments.

3. Risks to building fabric from moisture, wind and driving rain (H5)

As well as occupants, the bricks and mortar of homes are also at risk from climate change.

For example, increased damp due to flooding and intense rain, structural damage due to high winds and subsidence caused by drought. These can cause harm to occupant health and wellbeing and create significant repair costs for homeowners. The impact of climate change on these specific hazards is however highly uncertain as they are not well described in climate scenarios and evidence of the impact of climate hazards on building fabric is limited.

The risk is considered medium magnitude now and in the future in most scenarios. It would be helpful further to investigate the current and future costs of damage to housing building fabric caused by climate hazards.

Measures to improve energy efficiency in new and existing housing, such as increased insulation and airtightness, can lead to increased risk of moisture-related damage to building structure and the internal environment if additional ventilation is not also included.

Beneficial actions in the next five years include:

• Deliver more proactive actions to assess risks, as most adaptations related to building fabric are currently reactive, i.e. they happen after the damage has occurred to repair the home. Such actions include measurement of indoor environmental quality and better prediction of risks like subsidence.
• Taking a more integrated approach to design, in terms of energy efficiency, overheating and ventilation for new builds and retrofit to avoid issues like higher indoor vapour and mould growth.
• The most common adaptation response to windstorm risks is insurance. Retrofit interventions to existing homes like stronger doors and windows have high up-front costs but also high benefits. New builds could benefit from more consideration of siting, orientation, design and materials used in advance of construction to reduce the risks from wind.

Further details on this risk: Health, Communities and Built Environment Technical Chapter, risk H5

4. Risk to water quality and household water supply (H10)

Reduced summer precipitation resulting from climate change will increase the likelihood of periods of water scarcity which, together with demand increases from economic and population growth, may lead to interruptions of household water supplies. This would have health, social and economic impacts, particularly for vulnerable households.

Parts of the UK, particularly within south-east England are already water stressed.

Climate change may also increase the risk of contamination of drinking water through increased runoff and flooding events that overwhelm current water treatment approaches.

Assessments of the impacts of climate change on future water supply have found that low flows and deficits are more likely by the middle of the century in England and parts of Wales. Private water supplies are most vulnerable to current and future climate hazards that affect water quality (contamination with pathogens or chemicals) and quantity (interruption of supply) and are particularly important for more isolated communities. Recent hot summers have highlighted that private water supplies are vulnerable to dry and warmer weather and it is likely as the climate continues to change that more private supplies will dry out.

Beneficial actions in the next five years include:

• Improve water quality by reducing the risk of surface water flooding, including through implementation of sustainable urban drainage systems.
• Increased consideration in emergency planning so that responses to emergencies (e.g. exposure to chemicals in flood waters, or private water supplies being cut off) can be ramped up quickly as needed.
• Water companies are actively putting in place measures to bring household water demand down, like water metering and offering water efficient devices like low flow taps and toilets. Further reductions in water use by households would make them less vulnerable to water shortages, and the economic benefits are higher when these measures are built into new homes and/or when householders need to upgrade an appliance like a toilet or washing machine.

Further details on this risk: Health, Communities and Built Environment Technical Chapter, risk H10

5. Risks and opportunities from summer and winter household energy demand (H6)

Household heating demand dominates energy use in housing at present. Future heating demand will be reduced by climate change due to warmer winters, and cooling demand is likely to increase in summer, though this is very dependent on how much households take up mechanical cooling measures like fans and air conditioning.

Reduced heating demand may reduce winter fuel poverty, but ‘summer fuel poverty,’ where householders may not be able to afford cooling, could rise.

The exact level of risk or opportunity, trading off between reduced heating and increased cooling, remains hard to quantify.

In addition, changing energy policy to meet the UK and devolved administration Net Zero carbon targets will have a high influence on this opportunity as there will be big changes in fuel types used, total electricity demand given increasing electrification of the energy grid, and the types of heating and cooling devices that will be most effective in homes given these changing demands in winter and summer. For example, smaller heat pumps may be better given the change to warmer winters.

Beneficial actions in the next five years include:

• Policies and strategies for heating and cooling in dwellings would be more successful if they include consideration of the changing climate and its effect on energy demand in homes alongside the need to decarbonise. The size of the potential for reduced household energy costs, lower emissions and better indoor environmental quality is enormous if an integrated approach is taken that looks at adaptation and emissions reduction together.
• At the same time, keeping track of the UK’s Net Zero policies is important. The fast pace of the development of these policies could affect future options that do not represent the best approach if adaptation is left out.
• This risk/opportunity has been highlighted as particularly likely to benefit from an adaptive pathway approach, meaning various policy choices are mapped out against different future climate change and Net Zero scenarios, and the choices are narrowed down over time as uncertainty decreases. Adaptive pathways are used routinely in the flooding and water sectors, but to date have not been used widely in energy policy.

Further details on this risk and opportunity: Health, Communities and Built Environment Technical Chapter, risk/opportunity H6

6. Risks to health and wellbeing from changes in air quality (H7)

There remains a lack of evidence on the effects of climate change on indoor air quality, which can significantly affect occupant health and wellbeing in housing.

Poor indoor air quality may cause or aggravate allergic and asthma symptoms, airborne respiratory infections, chronic obstructive pulmonary disease, cardiovascular disease and lung cancer.

Household energy efficiency measures related to achieving Net Zero greenhouse gas emissions have the potential to worsen indoor air quality unless specific measures are taken to avoid this.

Higher external temperatures may improve or reduce indoor air quality due to changes in behaviours such as patterns of window opening.

Beneficial actions in the next five years include:

• Use existing building regulation enforcement activities to improve indoor air quality and update existing ventilation standards.
• Ensuring good design, installation and performance of mechanical ventilation systems.
• These and other actions to improve indoor air quality in the current climate would also have benefits for any climate-driven reductions in indoor air quality.

Variations across the UK

Background

The UK Government is required by the UK Climate Change Act 2008 to assess the risks and opportunities from climate change to the UK every five years and respond to the risks via a National Adaptation Programme, covering England. The devolved administrations also publish their own adaptation programmes in response to the risk assessment.

For this third UK Climate Change Risk Assessment, the Government’s independent advisers on climate change, the Climate Change Committee (CCC), have been asked to prepare an independent risk assessment setting out the latest evidence on the risks and opportunities to the UK.

Over 450 people from more than 130 organisations have contributed to preparing the assessment. The risks have been assessed using the latest climate projections for the UK which were updated in 2018 by the Met Office. These briefings summarise some of the key topics that are assessed through the Technical Report, to enable readers to understand the key messages and where to find more detail.

Where to find more detail

Each risk or opportunity in this briefing has an identifier code linked to the full analysis, which is available in the CCRA3 Technical Report. Readers are encouraged to use these briefings to locate the parts of the Technical Report of most relevance to them.

Alternatively, if you would like a summary of the analysis by UK nation, please go to the national summary documents: