Timeline for changes to planning system

This timeline brings together an unusually complex period of change for planning in Horsham and across Sussex. Over the next three years, local plan-making, local government reorganisation, the creation of a Sussex Strategic Authority and Mayor, and national planning reforms will all be taking place at the same time.

‘Click this link to view the enlarged graphic:  Horsham_Sussex_Planning_Timeline 17.8.2026

The timeline highlights how several major planning processes are set to overlap between 2026 and 2029. While the Horsham Local Plan 2023-2040 is expected to be adopted in early 2027, work is already beginning on a new Horsham District Local Plan. At the same time, local government reorganisation is expected to abolish Horsham District Council in 2028, transferring planning responsibilities to a new unitary authority.

Alongside these local changes, a new Sussex Strategic Authority will be developing a Spatial Development Strategy (SDS), while national planning reforms introduced through the Planning and Infrastructure Act continue to be rolled out.

The result is a highly complex planning landscape in which responsibilities, governance structures and strategic planning frameworks are all changing simultaneously.

Why this matters

For Horsham district (and wider!) residents, communities and campaign groups, understanding the timing and interaction of these reforms is essential.

Decisions made over the next few years could shape where development takes place across Sussex for decades to come. The timeline illustrates the potential challenges of maintaining democratic accountability, ensuring continuity of evidence and policy, and delivering effective public engagement while major governance changes are under way.

It also raises important questions about how local plans, strategic planning policies and newly created authorities will work together during a period of significant transition.