Sequential test
A flood risk assessment is required for most proposed developments that are within a designated flood zone.
A sequential test may be required as part of a flood risk assessment. It compares the site for a proposed development with other available sites to determine which has the lowest flood risk.
A sequential test is required if:
- The development is in flood zone 2 or 3, AND
- A sequential test has not already been done for a development of the type proposed on the proposed site.
A sequential test is not required if:
- The development is a ‘minor development’ OR
- The development involves a change of use, unless it is a caravan, camping chalet, mobile home or park home site OR
- It is a development in flood zone 1, unless there are flooding issues in the area of the development.
The sequential test must conclude whether any of the alternative sites that have been identified have a lower risk of flooding than the proposed site. It should be submitted along with the flood risk assessment and the planning application to the local planning authority.
If the sequential test shows that it is not possible to use an alternative site, it may be necessary to undertake an exception test. This shows how flood risk will be managed on the proposed site and demonstrates that the sustainability benefits of the development to the community outweigh the flood risk.
For more information see: https://www.gov.uk/guidance/flood-risk-assessment-the-sequential-test-for-applicants
[edit] Related articles on Designing Buildings Wiki
- BREEAM Flood risk management.
- BREEAM Surface water run-off.
- Design flood event.
- Design flood level.
- Flood and Water Management Act.
- Flood defences
- Flood plain
- Flood risk
- Flood risk assessment.
- Flood risk management plan
- Flood zone
- Flood.
- Minor development.
- Planning for floods.
- Property flood resilience
- Sustainable urban drainage systems.
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Planning condition discharge in England and Wales
A brief exoplanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.