Spatial Development Strategy: England’s new strategic planning tier

 

A Spatial Development Strategy (SDS) is a high-level planning strategy for issues that need to be dealt with across a wider area than a single local planning authority. It sits above the detailed Local Plan and is intended to deal with genuinely strategic matters such as the overall scale and distribution of growth, major infrastructure and cross-boundary housing needs.

Once an SDS is operative, it forms part of the statutory development plan. That gives it real decision-making weight: it is not simply a regional vision or evidence-base document.

But there is an important 2026 warning. Parliament has enacted a new England-wide SDS system through the Planning and Infrastructure Act 2025, but as at 27 August 2026 the main new duty outside London has not yet been formally commenced. Authorities may be preparing for the system, but preparatory work and proposed SDS geographies are not the same thing as an adopted statutory strategy.

London is different. The London Plan is already a Spatial Development Strategy under the Greater London Authority legislation. The current adopted London Plan therefore already forms part of the development plan for London, while the Draft London Plan 2026 is an emerging replacement and is currently in statutory consultation.

 

The current position in August 2026

 

The new national system is easy to misunderstand because the legislation has been passed but implementation is still under way.

The Planning and Infrastructure Act 2025 inserted a new Part 1A into the Planning and Compulsory Purchase Act 2004. That framework requires strategic planning authorities to prepare an SDS and provides for the strategy, once adopted, to form part of the development plan. However, the substantive new Part 1A duty requires commencement regulations before it operates generally.

On 23 June 2026 the Government told Parliament that the new system was intended to be commenced later in 2026, with further regulations on preparation and examination intended for the autumn. Ministers also said they expected most strategic planning authorities to be required to submit an SDS timetable within 90 days of formal commencement.

That is more current than the Government’s February 2026 consultation, which had said commencement was then expected in the summer. Until the necessary commencement and secondary legislation are in place, authorities outside the existing SDS regimes can undertake preparatory work but cannot simply treat a developing strategic framework as an adopted SDS.

So if a council or combined authority says it is ‘working on its SDS’, always ask whether the statutory duty for that authority has actually commenced, whether the work is merely preparatory, whether a formal timetable exists, whether a draft has reached consultation or examination, and whether the strategy has actually been adopted.

The answer determines whether you are dealing with background strategy, an emerging material consideration or a document that forms part of the development plan.

 

What is a Spatial Development Strategy?

 

An SDS is intended to provide a strategic spatial framework across a sub-regional area. The August 2026 NPPF says Spatial Development Strategies should plan for a period of at least 25 years.

The point is to address matters which do not sensibly stop at a district or borough boundary. Housing markets, transport networks, major roads and railways, employment corridors, water and energy infrastructure, flood risk, nature recovery and large-scale growth frequently affect several local planning authorities at once.

The separate national New Towns Programme is another example of growth at that scale. Seven locations remain proposed, with the government now saying final programme locations and environmental assessments will be published before the end of 2026.

The August 2026 NPPF places Spatial Development Strategies at the strategic tier of the new plan-making framework. The detailed Local Plan remains the place for local allocations and policies. An SDS should not become a very large Local Plan covering several councils.

Government’s February 2026 SDS consultation describes their intended role as setting the framework for Local Plans, helping areas meet housing needs, coordinate strategic infrastructure, grow their economies and improve the environment and climate resilience.

 

Who will prepare a Spatial Development Strategy?

 

Under the new England-wide framework, the duty sits with a strategic planning authority. The legislation provides for strategic planning authorities to include combined authorities, combined county authorities and, where those structures do not apply, relevant upper-tier county councils and unitary authorities.

Where several principal authorities need to plan together, the Secretary of State can establish a strategic planning board. This allows an SDS geography to reflect a sensible strategic area rather than simply following the boundary of one council.

The Government consulted in February and March 2026 on proposed SDS geographies. Those proposals were expressly described as preparatory: the consultation itself said SDS areas would not be formally agreed until the relevant secondary legislation had been consulted on and laid.

This means a map published during the consultation is not, by itself, proof of the eventual statutory SDS area.

 

London is already using a Spatial Development Strategy

 

London should not be used as evidence that the new England-wide 2025 Act regime has already commenced, because London’s SDS has a separate and much older statutory basis.

The Mayor of London is required to prepare and keep under review a Spatial Development Strategy for Greater London under the Greater London Authority Act 1999. That strategy is the London Plan.

For a planning application in London, the adopted London Plan is therefore already part of the development plan alongside the relevant borough Local Plan and any made Neighbourhood Plan. It should not be treated as merely strategic background guidance.

A new Draft London Plan 2026 was published for statutory consultation on 16 July 2026. The consultation runs until 15 October 2026, with examination expected in 2027 and adoption currently anticipated in early 2028. Until a replacement is adopted, the existing adopted London Plan remains the operative SDS; the 2026 draft is emerging policy whose weight depends on its progress and the issues still unresolved.

 

What can a Spatial Development Strategy contain?

 

The enacted new statutory framework keeps an SDS at a genuinely strategic level. It must contain strategic policies dealing with the development and use of land where the matters are of strategic importance to the strategy area, together with reasoned justification and a plan period.

The legislation also allows an SDS to specify or describe strategic infrastructure and to address the amount or distribution of housing, including affordable and other housing, across the strategy area. This is one of the most important reasons for reintroducing strategic planning: housing need and infrastructure can be considered across a functional area rather than council by council in isolation.

The framework also requires climate change to be addressed and requires relevant nature recovery information to be taken into account. An SDS can therefore influence where major growth should broadly be directed and what strategic infrastructure or environmental response is needed to support it.

For housing, read this alongside our guide to Local Housing Need and the Standard Method. As the new SDS system becomes operative and strategies are adopted, the strategic tier will increasingly affect how housing requirements are distributed between Local Plan areas.

 

What can a Spatial Development Strategy not do?

 

The most important limitation is simple: an SDS is not a site-allocation plan.

The new statutory framework prevents an SDS from specifying particular sites where development should take place. It can identify broad locations and strategic directions, but detailed site allocations belong in the Local Plan or another plan with the legal power to make those allocations.

This distinction matters when reading maps. A broad growth corridor or strategic location in an SDS is not the same as a red-line housing allocation. Conversely, a Local Plan cannot simply ignore the strategic direction of an operative SDS merely because the exact site boundary is left for local plan-making.

The same principle helps explain the relationship with Green Belt. Strategic planning can identify where strategic change needs to be considered; detailed boundary work and site-level decisions are normally dealt with at the Local Plan level. The precise relationship will be tested through plan preparation and examination as the new system beds in.

 

How does a Spatial Development Strategy affect a Local Plan?

 

The new system is designed as a hierarchy, not as two unrelated plans covering the same ground.

Where an SDS is operative for an area, a new-style Local Plan must be in general conformity with it. The Local Plan then translates the strategic framework into local allocations, settlement policies, development-management policies and detailed place-based decisions.

General conformity does not mean every sentence must be identical. Government has described it as allowing some inconsistency while preventing a Local Plan from taking a completely different strategic approach. Whether a Local Plan is in general conformity will ultimately be tested through its examination.

Our guide to Local Plans explains the 2026 transition and the difference between the old and new local plan-making systems.

 

Does a Spatial Development Strategy affect a planning application?

 

Yes, once it is operative. An adopted SDS forms part of the statutory development plan. The familiar section 38(6) starting point therefore applies: the decision is made in accordance with the development plan unless material considerations indicate otherwise.

That is already a live issue in London because the adopted London Plan is an operative SDS.

Elsewhere, be careful not to jump ahead of the legislation. A proposed SDS geography, a mayoral growth document, a non-statutory spatial framework or preparatory SDS evidence is not automatically an adopted development-plan document. An emerging SDS may become a material consideration as it progresses, but its legal status and weight must be identified accurately.

The strategic tier will also increasingly matter for major applications. See our update on the proposed mayoral planning powers for major development, including the planned call-in and direction-to-refuse powers outside London.

If you are writing a Planning Statement, state exactly which strategic document is adopted, which is emerging and which is merely preparatory. Do not cite a future SDS as though section 38(6) already applies to it.

 

Housing need, infrastructure and cross-boundary growth

 

Housing is likely to be one of the most significant practical effects of the new SDS system. Government has said SDSs can set the overall scale and distribution of growth and can redistribute housing and other development needs between Local Planning Authorities.

That gives the strategic tier a role in answering a question which individual Local Plans have often struggled with: if one authority cannot sensibly accommodate all of its needs, where across the wider functional area should that growth go, and what infrastructure is required to make it work?

The SDS is therefore intended to connect housing with transport, utilities, employment, environmental constraints and major infrastructure rather than treating the housing number as an isolated exercise.

For the separate calculations and monitoring tests, see our guides to Local Housing Need, five-year housing land supply and the Housing Delivery Test. Where Traveller accommodation need is identified, an SDS should also set pitch and plot requirements for each authority in its area; our Gypsy and Traveller sites guide explains the separate five-year Traveller-site supply.

 

How will a new Spatial Development Strategy be prepared and examined?

 

The 2025 Act establishes the broad statutory framework, including preparation, public participation, examination, adoption, monitoring, alteration and replacement. Unless the Secretary of State directs otherwise, the draft strategy is to be examined by a person appointed by the Secretary of State.

However, this is another area where the August 2026 implementation position matters. The Government told Parliament in June that further statutory instruments would set out the detailed preparation procedure and examination rules and were intended to be made in the autumn.

The Planning Inspectorate’s current new-system guidance similarly says further detailed guidance on new plan examinations will be made available during 2026. Older Inspectorate guidance on SDS examinations largely reflects the pre-2025 London and combined-authority regimes, so it should not be assumed to describe every procedural detail of the forthcoming England-wide system.

The August 2026 NPPF now provides the national policy framework against which new SDSs should be prepared. As the remaining regulations and guidance are issued, the statutory procedure will become much clearer.

 

Do not confuse an SDS with these other documents

 

• Local Plan: the detailed council-level plan containing local strategy, allocations and policies. See Local Plans
• Supplementary Plan: a statutory development-plan document with a much narrower role, normally site-specific or design-focused. See Supplementary Plans and SPDs
• Neighbourhood Plan: a community-led plan for a neighbourhood area which forms part of the development plan once it reaches the relevant statutory stage. See Neighbourhood Plans
• Growth plan, spatial framework or infrastructure strategy: potentially important evidence or strategy, but the title does not by itself make it a statutory SDS
• Policies map: the statutory map showing where development-plan policies apply; it is not itself a substitute for the strategic policies in an SDS

 

Practical checklist: does a Spatial Development Strategy matter to your site?

 

• Identify the area. Is the site in London or another area with an operative SDS regime?
• Check adoption status. An adopted SDS and an emerging draft are not the same thing
• Outside London, check commencement. Do not assume the new 2025 Act duty is operational merely because preparatory work has begun
• Check the SDS geography. Consultation proposals are not necessarily the final statutory boundary
• Read the Local Plan alongside it. The SDS sets the strategic framework; the Local Plan normally provides detailed allocations and policies
• Check housing and infrastructure implications. Strategic distribution may affect the assumptions behind future Local Plans
• For a live application, distinguish adopted from emerging policy. Give each document the status and weight it actually has
• Watch for commencement regulations. The national system is still moving quickly during 2026

 

Where to go next

 

Start with our guide to the Development Plan for the statutory hierarchy. Then see Local Plans for the detailed local tier, the NPPF explained for current national policy, Supplementary Plans and SPDs for the new supplementary tier and Neighbourhood Plans for community-led policy.

For housing strategy, continue with Local Housing Need and five-year housing land supply.

 

Costs and what happens after refusal

 

There is no separate fee for checking or relying on a Spatial Development Strategy. Any planning application fee depends on the route being used, so check our planning fees page. Professional advice, planning statements and technical evidence may involve separate costs.

If an application is refused, the applicant will normally have a right of appeal. An operative SDS forms part of the development plan, while an emerging strategy carries only the weight justified by its stage and unresolved issues. See our planning appeals section and check the relevant deadline early.

 

Relevant legislation and current Government material

 

The England-wide SDS system is still being commenced and implemented. Check current legislation and Government material rather than relying on an older guide to strategic planning.

• Planning and Infrastructure Act 2025, section 58 – creates the new England-wide statutory framework for Spatial Development Strategies;
• Greater London Authority Act 1999, section 334 – statutory basis for London’s Spatial Development Strategy;
• Levelling-up and Regeneration Act 2023 explanatory notes – including prospective changes to the London SDS framework and Local Plan general-conformity provisions
• Government consultation on areas for producing Spatial Development Strategies – proposed geographies and preparatory work;
• Hansard, 23 June 2026 – current Government implementation and commencement timetable;
• Planning Inspectorate new-system examination guidance – current implementation information;
• Draft London Plan 2026 statutory consultation decision – current London SDS position;
• National Planning Policy Framework – current national plan-making policy

Other Planning Policy Sections

 

Spatial Development Strategy Page Updated: 3rd September 2026