a river running through a city next to tall buildings

Sequential Tests for Flooding

At Cedar Planning we have vast experience in Sequential Tests, so contact us today to find out how we can help you.

What is a Sequential Test?

A Sequential Test is a requirement under national planning policy when your proposed development is at risk of flooding. It ensures that any development cannot reasonably be placed on a site with lower flood risk. That means identifying and evaluating alternative sites or locations and justifying why your chosen site is the most appropriate.

When You'll Need a Sequential Test?

You’ll generally need to carry out a sequential test if your site falls into:

  • Flood Zones 2 or 3

  • Areas prone to surface water, groundwater, or other flood risks

There are exceptions. In some cases, smaller developments (such as householder extensions or minor non-residential works under specified size thresholds), or change of use applications, may not require a full sequential test. Where sites are already allocated in the local plan and previously assessed, the test may have already been satisfied.

Recent changes to planning guidance also state that a Sequential Test should not be required where a site is subject to surface water flooding, and the risks can be effectively mitigated.

Defining “Reasonably Available” Alternative Sites

A key part of the sequential test is proving there are no reasonably available alternative sites. These are sites that:

  • Are in a suitable location for your proposed development

  • Can be delivered in a comparable timeframe

  • Meet your size, access, and infrastructure requirements

Often this involves reviewing multiple smaller sites, or parts of larger ones, to ensure a thorough search and robust justification.

Exception Test: What Happens Next

If your development passes the sequential test but remains in high-risk flood zones, you may also need to satisfy the Exception Test. This requires you to show that:

  • The benefits of your development outweigh flood risks

  • User safety over the lifetime of the development is assured

  • There is no increased flood risk elsewhere

people walking on bridge near buildings during daytime
people walking on bridge near buildings during daytime
a river running through a city next to tall buildings
a river running through a city next to tall buildings

Why Choose Cedar Planning for Your Sequential Test

We combine technical expertise with a client-focused process:

  • Local authority engagement: we agree search parameters with your council to align with policy expectations.

  • Detailed alternative site analysis: we conduct robust comparative studies to support your case.

  • Compliance: our sequential tests meet all relevant planning policy and flood risk guidance.

  • Clear, honest assessments: if chances of approval are low, we’ll tell you.

Our Process

  • Initial consultation & site review – understand your site’s risk profile.

  • Agree search area and criteria with you and the council.

  • Locate and assess alternative sites.

  • Produce a full Sequential Test report, with maps, risk analysis, and recommendations.

  • Support through submission and discussions with planning authorities.

Benefits of Using a Professional Sequential Test Service

  • Maximises your chance of planning approval

  • Saves time & reduces risk of refusals or appeals

  • Ensures compliance with both national and local policy

  • Offers peace of mind with well-documented evidence

Get a Free Quote for a Sequential Test

Let’s assess whether a sequential test is required for your development, and how strong your site’s case is. Fill out the form below for a no-obligation fixed-fee quote, or contact us directly to discuss your situation.