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
Classroom electrician courses a 'waste of money'
Say experts from the Electrical Contractors’ Association.
Wellbeing in Buildings TG 10/2025
BSRIA topic guide updates.
With brief background and WELL v2™.
From studies, to books to a new project, with founder Emma Walshaw.
Types of drawings for building design
Still one of the most popular articles the A-Z of drawings.
Who, or What Does the Building Safety Act Apply To?
From compliance to competence in brief.
The remarkable story of a Highland architect.
Commissioning Responsibilities Framework BG 88/2025
BSRIA guidance on establishing clear roles and responsibilities for commissioning tasks.
An architectural movement to love or hate.
Don’t take British stone for granted
It won’t survive on supplying the heritage sector alone.
The Constructing Excellence Value Toolkit
Driving value-based decision making in construction.
Meet CIOB event in Northern Ireland
Inspiring the next generation of construction talent.
Reasons for using MVHR systems
6 reasons for a whole-house approach to ventilation.
Supplementary Planning Documents, a reminder
As used by the City of London to introduce a Retrofit first policy.
The what, how, why and when of deposit return schemes
Circular economy steps for plastic bottles and cans in England and Northern Ireland draws.
Reporting on Payment Practices and Performance Regs
Approved amendment coming into effect 1 March 2025.