Southwest Environmental Limited

Minor Development In Relation to Exceptions and Sequential Test

With regards to Minor Development In Relation to Exceptions and Sequential Test Annex B of PPS25, D15, Minor development, states that applications for minor development and  changes of use should not be subject to the Sequential or Exception Tests but will still have to meet  the requirements for FRAs and flood risk reduction.  This sound helpful but in reality the definition is unclear

A - Annex B of PPS25, D15 Definition of Minor Development

Minor developments are unlikely to raise significant flood risk issues unless they would:

a) have an adverse effect on a watercourse, floodplain or its flood defenses;
b) would impede access to flood defense and management facilities; or
c) where the cumulative impact of such developments would have a significant effect on local flood storage capacity or flood flows.

It is believed that none of the above will be affected by this development.

B - Ministry of Housing, Communities and Local Government Minor & Major Developments

For dwellings, minor development is one where the number of dwellings to be constructed is between 1 and 9 inclusive. Where the number of dwellings to be constructed is not given in the application, a site area of less than 0.5 hectares should be used as the definition of a minor development. For all other uses, a minor development is one where the floor space to be built is less than 1,000 square metres or where the site area is less than 1 hectare. Decisions are classified as relating to a Major/Minor Development on the basis of the development covered by the application which was decided.

C - Other Criteria where Sequential Test may Not Apply . . . .

Minor Development In Relation to Exceptions and Sequential Test  - Conclusions

There are at least two definitions of Minor Development one in relation to flood risk, the other is relation to classification under PPS. The two do not match up. In addition to this we have a list of circumstances under which the sequential test specifically does not apply which again add variables to the situation.

There is a slight advantage gained from the above knowledge in that one might avoid having to complete the exception test if it meets criteria set out in A and B above. BUt it is unlikely as the EA may well argue that any development within a flood zone would have negative impacts of water course or flood storage, and as we would not carry out a flood risk assessment for a site in Zone 1 (unless for surface water drainage reasons) the advantage is lost.

Technical Guidance: Sequential and Exception Tests for Minor Developments

For minor developments located within Flood Zones 2 or 3, navigating the National Planning Policy Framework (NPPF) requires a clear understanding of the Sequential and Exception Tests. While "minor" projects—such as householder extensions or small non-residential footprints—often enjoy certain exemptions, they still require a site-specific Flood Risk Assessment (FRA) to demonstrate that the development will be safe for its lifetime.

Applying the Sequential Test to Minor Projects

The primary aim of the Sequential Test is to steer new development to areas with the lowest risk of flooding. For minor developments, the rules differ slightly:

• Householder Extensions: Generally exempt from the Sequential Test, though flood resilient design is still required.
• Change of Use: Usually exempt from the Sequential Test, but must still pass the Exception Test if the vulnerability of the use increases (e.g., office to residential).
• Small Non-Residential: Small-scale commercial projects must still demonstrate that there are no reasonably available alternative sites in lower-risk zones.

When is the Exception Test Required?

If the Sequential Test is passed (or is not applicable), the Exception Test may still be necessary to prove that the development provides wider sustainability benefits that outweigh flood risk. This is often integrated into the broader planning statement. Mitigation measures, such as flood resistant design or elevated floor levels, are critical pieces of evidence to satisfy this requirement.

Regulatory Compliance and Planning

Local Planning Authorities (LPAs) are increasingly strict regarding water management. Ensuring your project includes a robust SuDS strategy can help bridge the gap between policy requirements and site constraints. At SWEL, we integrate these technical findings into Environmental Impact Assessments (EIA) where necessary to provide a comprehensive route to consent.

Professional Technical Support

With over 15 years of industry experience and a track record of 900+ projects delivered across the UK, SWEL offers the professional accreditation and technical authority required to secure your project. We specialize in providing the technical evidence needed to satisfy the Environment Agency and Lead Local Flood Authorities. Whether you are dealing with a complex urban infill or a small rural extension, we provide the expertise to manage your sustainability strategy and planning hurdles effectively.