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
A five minute introduction.
50th Golden anniversary ECA Edmundson apprentice award
Showcasing the very best electrotechnical and engineering services for half a century.
Welsh government consults on HRBs and reg changes
Seeking feedback on a new regulatory regime and a broad range of issues.
CIOB Client Guide (2nd edition) March 2025
Free download covering statutory dutyholder roles under the Building Safety Act and much more.
AI and automation in 3D modelling and spatial design
Can almost half of design development tasks be automated?
Minister quizzed, as responsibility transfers to MHCLG and BSR publishes new building control guidance.
UK environmental regulations reform 2025
Amid wider new approaches to ensure regulators and regulation support growth.
The maintenance challenge of tenements.
BSRIA Statutory Compliance Inspection Checklist
BG80/2025 now significantly updated to include requirements related to important changes in legislation.
Shortlist for the 2025 Roofscape Design Awards
Talent and innovation showcase announcement from the trussed rafter industry.
OpenUSD possibilities: Look before you leap
Being ready for the OpenUSD solutions set to transform architecture and design.
Global Asbestos Awareness Week 2025
Highlighting the continuing threat to trades persons.
Retrofit of Buildings, a CIOB Technical Publication
Now available in Arabic and Chinese aswell as English.
The context, schemes, standards, roles and relevance of the Building Safety Act.
Retrofit 25 – What's Stopping Us?
Exhibition Opens at The Building Centre.
Types of work to existing buildings
A simple circular economy wiki breakdown with further links.
A threat to the creativity that makes London special.