A sequence of recent decisions have highlighted the current thinking around viability, and these are a timely reminder to practitioners of the vital importance of viability in the planning process.

Arun District Council - BEW Parcel SC1, Barnham
On 21 July 2025, Arun District Council resolved to grant planning permission for a new development comprised of 1,250 homes (and associated infrastructure) in Barnham.

The development proposed a 15% rate of affordable housing and reduced education contributions due to viability issues. The Council’s Local Plan required 30% affordable housing on major sites.

The Council had a land supply position of 3.4 years. The Officer Report identified that this meant that the Council’s Local Plan was out of date, and in that context the Report recommended approval.

That approval was subject to an acceptable Section 106 Agreement, and in this respect the Council relied on the inclusion of an upwards-only review mechanism. This review mechanism ensured that the affordable housing position was reviewed on an ongoing basis, and to the extent that the viability position changed going forward, the developer would be required to make an increased contribution to affordable housing.