The roll-out of strategic planning has started, reflecting the last Government’s intention that there would be England-wide coverage by the end of this Parliament, expected to be in Summer 2029. Strategic planning will be via spatial development strategies (SDS), albeit there is a current separate consultation on Mayors of strategic authorities having development management powers ahead of an SDS being published
[1].
The legislative basis for SDSs and the bodies that prepare them is in the Planning and Infrastructure Act 2025 and the English Devolution and Community Empowerment Act 2026.
Earlier Lichfields analysis of the legislation and of a consultation on SDS geographies provides a background to this blog.
The last Government consulted on the proposed geographies over which each SDS will apply, from February to March 2026, with the outcome awaited. The Lichfields blog
Spatial Development Strategy Geographies: Will the map change the landscape? considered the make-up of the proposed new geographies and explored some metrics related to two of their key priorities: meeting housing needs and growing the economy. The findings of that blog remain relevant, so we do not delve into them here.
Bethan Haynes explained the intention and challenges for SDSs, including how they are administered, and reflected on the (then) Planning and Infrastructure Bill requirements, in her
blog of March 2025[2]. A follow up to that blog, ‘Big plan theory’, considered the progress that had been made on SDSs by the end of last year
[3]. In that blog, Ed, Dom and Myles considered changes to the then English Devolution and Community Empowerment Bill as it had progressed through the Houses. This blog further considers some of the queries raised in the 'Big plan theory' blog, with reference to the NPPF as now published.
Beyond the legislation and the awaited consultation outcome on geographies, the National Planning Policy Framework (NPPF)
[4] sets out the national policy for plan-making, including 17 specific plan-making policies. This blog focuses on plan-making policies particularly applicable to SDS preparation.
The NPPF defines a spatial development strategy in its glossary at Annex A:
“Spatial development strategy: A plan containing policies on the development and use of land on matters of strategic importance to the area prepared by strategic planning authorities and the Mayor of London”.
National plan-making policies
The NPPF’s introduction explains that there is some interpretation needed when applying national policy to Spatial Development Strategies (SDS), because whether SDS, local plans and/or supplementary plans address certain thematic plan-making policies will depend on the area to which the plan relates.
This is discussed further below, in the context of the need for collaboration across boundaries and between bodies.
It also reminds of an important point when considering the role of SDS in the development plan: “The relevant legislation does not allow spatial development strategies to allocate specific sites or designate specific areas of land”.
The NPPF also explains how SDS should be prepared and examined. Policy PM14 says that a sound SDS should satisfy tests of being “positive”, “appropriate”, "effective" and "consistent with national policy".
PM1: Spatial development strategies
Policy PM1 is the overarching national policy regarding the preparation of SDS. PM1(1) sets the tone:
“[An SDS should] set a positive vision for future growth and change at a sub-regional scale and provide a clear spatial framework for investment and growth, including for new housing”
Setting out the aims of an SDS, the NPPF is clear that its “Content should be genuinely strategic in nature”. Parliamentary debates during the passage of SDS related legislation made clear that the last Government and other politicians were keen to avoid future strategic plans having the length or detail of the London Plan.
The draft new London Plan is out for consultation at present. Sally Furminger and Ross Raftery's blog '
Assessing the draft London Plan's position on housing: does it make the grade?' observes that the emerging London Plan is likely to be the first SDS to be tested against the NPPF 2026. Sally and Ross give an initial verdict on the draft London Plan’s approach to housing matters against the tests of soundness in the then draft NPPF policy PM14, which is broadly unchanged in the final version. They conclude that
"There is a positive shift in approach, but some policies and the new 'boxes' remain long and detailed". It will be interesting to see the extent to which the final published London Plan provides a model for strategic authorities outside of London, albeit that London has unique issues which mean that its SDSs are always likely to be somewhat different to others in England. The current will naturally be a trailblazer against the NPPF in any event.
The current Government has continued to seek to design the system to avoid unnecessary policy duplication or complication, including the ‘layering’ of policies. More detailed or locally specific issues should go into local or supplementary plans as
“other parts of the development plan” or will have been picked up through National Decision Making Policies
[5] .
The NPPF sets out nine ways that the positive vision, clear spatial framework and genuinely strategic content should be achieved, lettered a-i, which provides a list of minimum contents, evidence and analysis for SDSs (PM1(2)).
We review or provide a summary of each.
Plan period, monitoring and implementation – strategic means strategic
PM1(2) a. and b. set out timescales and the locations for growth that should be identified.
“a. Setting out a strategy for a sustainable pattern of growth covering a period of at least 25 years, including through the apportionment to local planning authorities in the strategy area of objectively assessed needs for housing and other uses that are best considered at a strategic scale for the duration of the plan period;”
And
“b. Identifying broad locations for growth and regeneration, including new settlements, major urban extensions, major cross-boundary development and other key locations with the potential for significant new homes, jobs and other development [which should extend over strategic site allocations in adopted plans]”;
The draft NPPF consultation document proposed a 20-year period. The Government has increased this to 25 years
“To support long-term certainty for planning, infrastructure delivery and investment”, according to its response to the national policy consultation
[6].
The 25-year period is a different timescale to the 10 years for which an LPA must consider housing needs via the local plan (the local plan period was to be 15 years in the consultation NPPF).
The SDS period should be read with the monitoring and implementation policy for SDSs, set out at i. This says that commencing preparation of a replacement or altered version should happen no later than seven years after the current version was adopted, or earlier, if certain criteria are met. The criteria are essentially where either the strategic planning authority or Mayor of London consider the SDS inconsistent with national policy, or changes are planned to infrastructure that might affect delivery or to respond to new evidence that show significant changes to needs, opportunities or development constraints.
Setting strategic development locations will be a key priority for SDSs; the ability to plan over 25 years will allow for medium to large sites to be planned for in this way along with enabling infrastructure. However, our research on
planning and
development timelines has shown, that for the largest of sites for example new settlements, this time frame will remain challenging.
Indeed, the last NPPF (2024) was clear that “Where larger scale developments such as new settlements or significant extensions to existing villages and towns form part of the strategy for the area, policies should be set within a vision that looks further ahead (at least 30 years), to take into account the likely timescale for delivery”. If, as directed by PM1, SDS should identify ‘broad locations’ for growth and if HO4 requires development plans to identify suitable locations for strategic sites for housing-led development – both of which includes new settlements – SDS should surely look ahead at least 30 years?
The interface of plan-making, between SDS and local plans, is explored in Matthew Spry’s recent blog
Make more little Plans? The NPPF’s shift to ten-year local plan periods.
PM1 says SDSs should also be:
“c. Supporting economic growth by providing a spatial framework for strategic investments and giving spatial expression to strategic elements of Local Growth Plans and the Industrial Strategy[…];
d. Identifying the general extent of areas established as Green Belt and broad locations where changes to Green Belt boundaries may need to be considered through local plan preparation, if necessary to meet the development needs of the strategy area;
e. Identifying broad locations for nature conservation and habitat enhancement, restoration and creation; and addressing strategic issues relating to the protection and enhancement of the historic environment;
f. Setting out the type, extent and broad location of strategic infrastructure needed to enable development and serve existing communities […] [and make provision for certain committed infrastructure];
g. Using appropriate maps and diagrams to illustrate and communicate the strategy;
h. Providing a proportionate level of information on the mechanisms for delivering the strategy”
[…];”
The SDS will be expected to identify the broad locations for infrastructure investments, and other aspects (as above) with local plans covering the detail. The ‘general extent’ of Green Belt boundaries might be open to interpretation and will likely be contested locally in areas with Green Belt constraints, where the combined housing needs of an SDS area are high.
With regard to requirement g., appropriate maps and diagrams, policy S2(2) (Producing a spatial strategy) says:
“The spatial strategy should be illustrated on a key diagram forming part of a spatial development strategy and/or local plan (or minerals and waste plan, where relevant), with the boundaries of specific policy areas, land-use designations and allocations identified on a policies map”.
The policies map
[7] is a map required by the new plan-making system, which identifies all the development plan allocations on an Ordnance Survey base. A spatial development strategy cannot allocate sites and so the key diagram will not be included on the policies map. The policies map allocations are the fine grained, follow up to the broad locations identified on the key diagram.
General principles – do not duplicate policy
In addition to the emphasis on SDSs planning at a strategic level in PM1, policy PM6 sets out plan-making principles that are applicable to all plan-makers, including SDS authors. Of note, plan-makers should:
a. Only address matters, and include policies, that are necessary and relevant to the plan being prepared, and that avoid unnecessary duplication of other parts of the development plan;
c. Not include policies which duplicate, substantively restate or are inconsistent with the content of national decision-making policies, unless directed by other policies in this Framework;
PM6(1)c. above reflects the "consistent with national policy" soundness test in PM14, as one would expect, albeit allowing for the NPPF itself to cause policy duplication, restatement or inconsistency. PM6(1)a. above indicates that duplication across a development plan might be acceptable in some instances, given that plan-makers should "avoid unnecessary duplication of other parts of the development plan" (our emphasis).
Overall, the NPPF seeks to establish a clear delineation between national, strategic and local policy in terms of policy formulation. However, establishing such policy boundaries will not be straightforward, as the NPPF itself acknowledges, because the NPPF leaves open to interpretation which level of policy making should address certain matters, as discussed below.
Local plan interface and cross-boundary cooperation
Policy PM10 sets the approach to maintaining cooperation on cross-boundary matters and PM11 on demonstrating cooperation.
PM10 requires plan-making authorities to engage “proactively and regularly with infrastructure providers, neighbouring and other relevant plan-making authorities (where there are strategic interdependencies across boundaries)”. It also requires similar engagement with “other relevant bodies” regarding the need to address cross-boundary matters, identifying additional infrastructure, identifying development needs extending beyond a plan area and determining optimal growth locations as needing such cooperation.
The Government’s response to the national policy consultation says that PM10 and PM11 “support flexible and proportionate approach” and that guidance will also be published to support authorities in meeting those policies.
Acknowledging the wide range of bodies that the need for cooperation applies to, the response also says, “The government will also continue to work with relevant government departments and infrastructure bodies to improve alignment between long-term infrastructure planning and development plan-making, including through wider infrastructure planning reforms”.
The vision and spatial strategy of a local plan should support the delivery of the spatial development strategy (PM2). Relating back to that important interface between local plans and SDS, and linked to PM6 regarding duplication, PM10(3) also states that:
“Where matters are already addressed by an adopted spatial development strategy, plan-making authorities within the strategy area do not need to revisit them when preparing their plans”.
The ‘matters already addressed’ referred to in the policy wording includes housing targets i.e. SDSs will be required to set out each constituent LPA’s housing need figures against which their local plans and housing delivery test measurements will be assessed.
PM10(4) refers to using ‘available information’ a term carried over from the superseded NPPF 2024:
“Where there is uncertainty about the future direction of other parts of the development plan or the plans of infrastructure providers, such as due to misaligned timings, plan-making authorities should make pragmatic decisions on the basis of available information rather than waiting for a full set of evidence from other bodies”.
In many areas this is likely to be crucial, given the potential lag between an SDS and a local plan being prepared, as it avoids the pitfall of the uncertainty of ‘unmet need’ numbers.
A potential challenge to this new system is how to deal with the unmet need in an SDS that cannot meet its own housing needs within its boundaries. For example, an urban combined authority that might have previously (under the duty to co-operate) shared need with neighbouring local authorities, that form part of the same housing market area but are now in a different SDS. Essentially, the challenge is how to deal with unmet need that remains at an SDS level across different SDS areas.
A further key issue to consider here, and as noted above, is that some making policies in the NPPF ask that a matter is addressed “at the most appropriate plan level”.
The NPPF’s introduction says:
“The plan-making policies should be read as a whole (including relevant footnotes and annexes), and applied in a way that is appropriate to the type of plan being produced, the area that it covers and the period it is intended to cover. Reflecting this, some of the plan making policies indicate actions that should be taken at the most appropriate level, which recognises that plan-making arrangements will vary across the country (for example in the geographic scale of spatial development strategies and local plans). Where policies relate to matters that are primarily local in scale, and/or are concerned with detailed implementation, they will not generally apply to spatial development strategies."
In some cases, particularly where an allocation is referenced, this will mean deciding whether or not the policy should be in the local plan or in a new, statutory, supplementary plan, rather than in an SDS. In other cases, such as looking at housing need for different groups, providing for economic growth and/or avoiding constraints on expansion of renewable and low carbon energy, particular collaboration between SDS plan-makers and local plan-makers will be needed. Alternatively, it seems possible that if evidence shows that a local plan would be justified in addressing a given matter via a new policy, notwithstanding that a similar SDS policy addressing the matter being in place (and vice versa), that new policy can be adopted/published. In such a case, the most recent policy will prevail if there is any inconsistency
[8]. This alternative may also apply to the ‘matters already addressed’ in an SDS (PM2), discussed above.
The Government’s SDS geographies consultation said effective cooperation would be tested at examination and noted particular locations where such cooperation will be important:
“There are some large-scale growth areas that cross multiple SDSs, such as the Northern Growth Corridor, Oxford-Cambridge Growth Corridor or the Thames Estuary. The government will expect SDSs to be supportive of the growth ambitions of these areas and to have consistent approaches across SDS boundaries.
There are also several parts of the country where national park authorities straddle proposed SDS boundaries and are the local planning authorities. Engagement with these authorities will be particularly important for the relevant strategic planning authorities”.
In areas undergoing local government reorganisation and where there is some uncertainty over boundaries, there is an additional layer of matters to consider when SDS plan-makers and local plan-makers collaborate. The Government has said it will
“publish transitional regulations in due course to deal with the various plan-making complexities arising because of local government reorganisation”[9].
Positive plan-making
The plan-making policies within the chapter on achieving sustainable development and policy PM14 (Examining spatial development strategies), emphasise the need for positive plan-making. Policy S1 says that planning positively means providing for new development and environmental improvements in a way that promotes a sustainable pattern of growth and seeks to mitigate climate change and adapt to its effects. It also means “providing for objectively assessed needs for housing, business and other uses (including supporting infrastructure), as well as any needs that cannot be met within neighbouring areas, unless:
i) The application of the policies in this Framework that protect areas or assets of particular importance [FN24][10] provides a strong reason for restricting the overall scale, type or distribution of development in the plan area; or
ii) Any adverse impacts of doing so would substantially outweigh the benefits, when assessed against the policies in this Framework taken as a whole”.
With regard to the “positive” test of soundness, PM14(2)(a) says:
“The strategy sets out a positive approach to delivering growth which, as a minimum, seeks to meet the area’s objectively assessed needs, and is based on effective joint working on cross-boundary strategic matters. A strategy which does not provide for objectively assessed needs should be considered an exception, and only where it is evidenced that stringent efforts have been taken to meet those needs through cooperation with other strategic planning authorities”
The explicit reference to a need for the SDS to be positive is helpful, with the emphasis on these plans meeting their needs except when there is evidence “that stringent efforts have been taken to meet those needs”. Positive planning means “meeting the development needs of an area” is described as a minimum, for both SDSs and local plans.
Under this framework, an SDS becomes the basis for the level of development in an area (including as PM10 notes, housing need). SDS are considered to address both the duty to cooperate issues that arose in the last plan-making system and to address broader land supply challenges.
Other plan-making policies
National plan-making policies that expressly guide SDS preparation and application include:
- HO1/HO2 – SDS to assess the need for homes and establish a housing requirement
- M1 – SDS to assess the provision needed for aggregate and industrial minerals, where appropriate
- GB2 – assess the strategic role of Green Belt land within the strategy area and identify where boundaries may require further consideration in local plans
- TR1 – SDS may set thresholds for what constitutes a significant amount of [transport] movement arising from new development.
In addition to policies that expressly state what an SDS should include, SDS plan-makers will need to consider how to address themes that might require agreement between the strategic authority and its constituent local authorities as to which is the ‘most appropriate plan level’ for a given policy, as discussed above. These include policy E1, which says that development plans should, at the most appropriate level, provide the conditions for long-term economic growth.
Final thoughts
As noted in earlier Lichfields analysis, strategic planning has the potential to overcome some of the most significant barriers to development that we have seen over the last decade and to unlock a genuine solution to cross-boundary issues like infrastructure and housing. The ongoing challenge of local government reorganisation and strategic authorities will be key to ‘getting the geography right’ in some of the most politically sensitive areas, as well as the capacity and institution building necessary to get effective plans means that we are still a way off from universal coverage. Political crosswinds, economic challenges and the ongoing stasis in much of the economy will continue to challenge development in many areas. However, for the strategic authorities that are already in a position to start preparing their SDS, there is the potential to provide effective integrated strategic plans that reflect local needs and cover the next twenty five years of development.
“It is early days and a mixed picture. The strategic planning landscape in some areas continues to look auspicious, notably the Combined Authorities with mayors who are keen to win the race to be first to adopt an SDS”.
Work has started on SDSs in Strategic Authorities outside of London that are run by elected mayors. See Table 1 for our understanding of current progress in these authorities.
Table 1
|
Strategic authority
|
Status
|
Target adoption year
|
Notes
|
| Greater London |
Published |
Published 2021 |
Draft plan to replace existing plan released in July 2026, with adoption target of 2028. |
| Liverpool City Region |
In development |
2027 |
In preparation since 2019. Aiming to publish a draft version of the SDS for consultation in late 2026, with submission and possible adoption target of 2027. |
| East Midlands |
Early in development |
2028 |
Work formally approved in March 2026, with adoption target of 2028. |
| North East |
Early in development |
2028 |
Began preparation this summer. Aiming to be one of the first regions with an SDS in England, with submission target of late 2027 and adoption of 2028. |
| West of England and North Somerset |
Early in development |
2029 |
Begun preparation, with consultation target of autumn 2027 and adoption target of spring 2029. |
| Tees Valley |
Early in development |
Not yet announced |
Appointed a consultant to begin preparing an SDS in August 2026. |
| Cambridgeshire and Peterborough |
Early stage scoping |
Not yet announced |
|
| Greater Manchester |
Early stage scoping |
Not yet announced |
|
| West Midlands |
Early stage scoping |
Not yet announced |
|
| South Yorkshire |
Early stage scoping |
Not yet announced |
|
| West Yorkshire |
Early stage scoping |
Not yet announced |
|
| York and North Yorkshire |
Early stage scoping |
Not yet announced |
|
| Greater Lincolnshire |
Early stage scoping |
Not yet announced |
|
| Hull and East Yorkshire |
Early stage scoping |
Not yet announced |
|
[5] National decision-making policies are a critical material consideration when determining planning applications, according to the NPPF
[8] Section 38(5) of the Planning and Compulsory Purchase Act 2004
[10] Footnote 24 says: The policies referred to are those in this Framework (rather than those in development plans) relating to: habitats sites and/or designated as Sites of Special Scientific Interest; land designated as Green Belt, Local Green Space, a National Landscape, a National Park (or within the Broads Authority) or defined as Heritage Coast; irreplaceable habitats; designated heritage assets; and areas at risk of flooding or coastal change.