The new National Planning Policy Framework (NPPF), published in August 2026, brings an important change for surface water drainage design. SuDS are now expected for all development with drainage implications.

What does this mean for developers and design teams? The NPPF requires them to be designed in accordance with the new National Standards for Sustainable Drainage Systems. For developers and design teams, this strengthens requirements around how surface water is considered from the outset.

The National Standards introduce clearer expectations for the drainage hierarchy, management of the first 5mm of rainfall, runoff rates and volumes, water quality, biodiversity and amenity. The result is a greater need to integrate drainage and SuDS into site layouts at an early stage, rather than treating drainage as a below ground exercise once the wider design has been fixed.

There is no grace period. These rules apply immediately to live planning applications. Designing layouts without an upfront drainage strategy is now a major risk to achieving planning approval.

At Symmetrys, we specialise in integrating creative, compliant, and cost-effective civil engineering solutions from day one. Our team is ready to help you navigate these updates, de-risk your layouts to secure your Annex C compliance statements.