Last updated: 19 May 2026
Flood resilience and new homes explained
Key points
- The home building industry supports robust protections against flooding, and recognises the importance of ensuring that new homes are delivered in a way that is resilient to flood risk.
- Flood risk is an important consideration in the planning system, and the planning and regulatory frameworks contain extensive protections to ensure development is directed away from risk wherever possible and only permitted where it can be shown to be safe.
- There has been no material weakening of protections through the September 2025 Planning Practice Guidance updates or the draft revised National Planning Policy Framework (NPPF), and the core principle that development must be safe and properly mitigated against flood risk remains in place.
- Headline figures about homes ‘built in flood zones’ do not reflect either the protections embedded in the planning system, or the distinction between sites identified as being at risk of flooding and the location of homes within those sites.
What is the industry’s position?
The home building industry supports robust protections against flooding, and recognises the importance of ensuring that new homes are delivered in a way that is resilient to flood risk. Throughout the planning process, home building companies work closely with Local Planning Authorities, the Environment Agency and Lead Local Flood Authorities (LLFAs) to ensure flood risk is properly considered and mitigated.
Recent commentary from some insurers, as well as proposals brought forward through a Private Members Bill in the House of Commons, has suggested that changes to planning policy have weakened flood protections and led to more homes being built in areas at risk of flooding. Such commentary overlooks the safeguards already embedded in the planning system and does not reflect the way flood risk is managed and assessed in practice for new developments. The claims made by insurer, Aviva in a press release earlier this year were addressed by the Ministry of Housing, Communities and Local Government, with the government spokesperson rightly describing them as ‘misleading’.
How does the planning system safeguard against flood risk on new developments?
The National Planning Policy Framework (NPPF) is clear that inappropriate development should be directed away from areas at the highest risk of flooding wherever possible. Where sites are available in areas of lower flood risk, development should not be allocated or permitted in higher-risk areas.
To support this, a sequential, risk-based approach is applied to any sites at current or future risk of flooding, requiring development to be steered first to areas of lowest flood risk. This ‘Sequential Test’ applies both when allocating sites through Local Plans and when determining individual planning applications.
Where development cannot reasonably be located elsewhere, a further safeguard applies through the ‘Exception Test’. This test requires it to be demonstrated that development will be safe for its lifetime, not increase flood risk elsewhere, take into account the vulnerability of its users, and reduce flood risk overall where possible. The development must also provide wider sustainability benefits that outweigh the flood risk.
Further safeguards apply even where the Exception Test is met. As well as Flood Risk Assessments (summarised below), national planning policy requires development to be appropriately designed and resilient, to incorporate sustainable drainage systems unless clearly inappropriate, to manage residual risks, and to provide safe access and escape arrangements where appropriate.
Taken together, these measures provide a robust framework for managing flood risk through the planning system.
What changes have been made to planning policy in relation to flood risk?
There has been no material weakening of protections through the September 2025 Planning Practice Guidance updates or the draft revised NPPF.
Instead, these recent changes clarify that the sequential test may not be required where flood risk arises solely from surface water flooding, provided a site-specific Flood Risk Assessment demonstrates - through the proposed layout, design and mitigation measures - that the development would be safe for its lifetime and not increase flood risk elsewhere.
These updates, which are taken forward in the draft NPPF, do not alter the core principle that development must be safe and properly mitigated against flood risk.
What is the role of Flood Risk Assessments?
Flood Risk Assessments (FRAs) are required to support development in Flood Zones 2 and 3 (representing areas at medium or high risk of flooding) and are another safeguard alongside planning policy requirements. FRAs are considered by the Environment Agency or LLFAs and, depending on the nature of the site, can involve detailed hydraulic modelling and extensive technical assessment.
These assessments identify flood risks affecting a site, the measures needed to manage those risks, and how development can proceed safely without increasing flood risk elsewhere. In some cases, they can also help reduce flood risk overall and support wider water management objectives.
Mitigations can include raised development levels, controlled flood storage, sustainable drainage systems (SuDS), permeable paving, and measures to manage flood routes through a development. These measures form part of the basis on which planning permission is granted and, where required, must be in place before homes are occupied. Their delivery is monitored and approved through both the local planning authority and building control processes.
What about claims that new homes are built in high flood risk areas?
Recent commentary has focused on the number of homes delivered on sites identified as being in medium or high-flood-risk areas. However, while national flood mapping may show that part of a site is at risk, this does not mean the new homes themselves are located in unsafe areas.
For example, a site boundary may include land within Flood Zone 3 - land identified as having a higher probability of river or sea flooding - while the homes delivered on the site sit outside those areas. In such cases, higher-risk land may instead be used for open space, drainage, or flood storage rather than housing. Part of a site may therefore be identified as lying partly within Flood Zone 3 without new homes being located within those higher-risk areas.
Furthermore, to support individual planning applications, detailed site-specific modelling is undertaken. This modelling often provides a more accurate understanding of whether and where a site is at risk than national flood mapping, such as the National Flood Risk Assessment, which is strategic and broad in nature. In some instances, this more detailed modelling can show that flood risk is more limited than national mapping suggests. Site-specific modelling is also scrutinised by either the Lead Local Flood Authority or, where flooding relates to a main river, the Environment Agency.
Finally, as was noted by MHCLG in its response to the Aviva campaign, ‘figures quoted in Aviva’s research are misleading as they don’t factor in flood defences currently in place. For example, much of the Cities of London & Westminster are in a flood risk area but are defended by the Thames Barrier’.
For these reasons, headline figures about homes ‘built in flood zones’ do not account for whether new homes are actually located in areas at flood risk, nor for the site-specific modelling and mitigation that inform planning decisions.
Where can I find more information?
- MHCLG’s response to claims on housebuilding and flooding
- Government guidance on flood risk and coastal change in the planning system
If you have any questions about flood risk and new build homes, contact our Policy team at policy@hbf.co.uk.
Find out more about our policy work
View the latest HBF correspondence with Government and recent activity