The carbon cost of restoring a flooded home: Building Future Communities

As part of our sustainability commitments to act on climate change and build stronger more resilient communities, we're calling for urgent action to make UK homes more climate ready.

While we are working towards our sustainability ambitions, we acknowledge that we have relationships with businesses and existing assets that may be associated with significant emissions. Visit our sustainability page to learn more about our climate goals.

In the second edition of the Building Future Communities report, our analysis shows the significant carbon impact of restoring a flooded home and calls for homes to be restored and built resiliently to withstand a future of extreme weather. ¹ The report shows that the carbon cost of restoring a flooded home can be equivalent to six and a half return flights from London to New York²or 55 car trips from Land’s End to John O’Groats.³

In our report, we argue that building and restoring resilient UK properties is essential to tackling climate change and reducing emissions associated with flood damage. We're calling on the Government to introduce stronger planning regulations with resilience factored in, increased collaboration during all stages of the building process, and take steps to encourage and incentivise property resilience.

The carbon cost of a flood

We calculated the carbon cost of a river flood event on a UK home - a three-bed, semi-detached, pre-1930s property. We compared the carbon emissions due to the flood event in two different scenarios: one when the property had no flood resilience measures and the second with simple measures installed such as flood doors, sealed brickwork and raised electrical points. The outcome was very different, depending on whether resilience measures were in place.

Without any property flood resilience measures in place, we found the carbon cost of restoring the flooded home was 13.9 tonnes of CO2e emissions. In addition, a home without resilience measures installed could lead to homeowners having to move out of their home for a considerable period. 

Putting in place simple property flood resilience measures is projected to lead to a 64% reduction in the carbon cost of a flood and decrease the depth of flood water to 20-30mm. In turn, this means residents can remain in their homes which can help to lessen the emotional toll of a flood.

Analysis: table/infographic: Summary of impact on home with & without resilience measures³

In our analysis, the biggest savings in carbon emissions from property flood resilience measures were in building restoration, with a saving of 5.2 tonnes CO2e, largely due to lower water levels, which led to less damage in the home. In turn this meant fewer materials were needed to replace fixtures and fittings and less waste was produced. Emission savings were also made on the home contents (2.6 tonnes CO2e), as many items could be repaired rather than replaced. Importantly, carbon emissions associated with alternative accommodation – whereby a resident needs to move to temporary accommodation – reduced by 100% when resilience measures were installed because people were able to stay in their homes.

Household sentiment

The extreme weather of 2022 appears to have made people more aware of the threats of climate change. Our research found that 45% of people think climate change will impact their home in the next year, compared to 38% in 2021, rising to 65% in 10 years (2021: 57%).⁴ And although 80% of UK residents think homes should be resilient to extreme weather, the majority (67%)² have not installed resilience measures in their homes.

Aviva’s calls for change

From the seven calls for change in its first Building Future Communities report, in the latest report we're focused on calling for:

• Strengthen planning regulations to protect UK properties
• More collaboration and research across all stages of the building process to combine sustainability with safety
• Encourage and incentivise property resilience to aid recovery

Adam Winslow, CEO GI UK & Ireland said:            

“With ambitious government plans to build new homes, it is crucial that any housing developments built on flood plains benefit from dual protection; flood defence systems to help prevent flooding in whole communities and resilience measures to minimise disruption. Unless more urgent action is taken to make our homes climate-ready, properties will be exposed to multiple threats from extreme weather, be it flooding, subsidence or over-heating. We simply cannot continue with the current status quo. Now is the time to act to make existing and future properties fit and prepared for the climate threats they will face in future.”

^{1 The homes modelled, and their contents, are theoretical, but based on a real claim made on a property insured by Aviva. In modelling the carbon emissions associated with a flood in these theoretical properties, best estimates of the Aviva claims team have been used, as both actual figures and national average figures are unavailable.}

^{2 Based on 5,570km travelled one way. 2022 UK BEIS conversion factor for an average passenger taking a long-haul flight.}

^{3 Based on a medium-sized petrol car and 2022 UK BEIS land travel conversion factors.}

^{4 Research commissioned by Census wide for Aviva in July 2022.}

^{5 Impacts calculated based on Aviva claims team estimates.}