Planning matters

Spatial Development Strategies (SDSs) could potentially play a key role in supporting local plan-making and achieving the Government's objective of delivering 1.5m homes across this Parliament. With the principle of strategic planning forming a key part of the Government’s proposed planning reforms, the Planning and Infrastructure Bill represents the next step towards bringing strategic planning – with all its strengths and opportunities - back to the forefront of plan-making. But what are some of the immediate challenges that need to be considered, and what questions remain unanswered?

The Planning and Infrastructure Bill sets out the process by which certain authorities should prepare strategic plans; largely following the processes (including scope for intervention by the Secretary of State [SoS]) already set out for local plan-making – shown in Figure 1. The initial step will involve establishing geographies, which we understand to be subject to a consultation process by Government later this year. Combined, combined county, upper-tier and unitary authorities (not within a combined authority) are ‘principal authorities’ and are strategic planning authorities (SPAs); they can join together to form a Strategic Planning Board (SPB) covering multiple SPAs, if appropriate (and the SoS can also intervene in establishing SPBs, if needed).

Once established, much like current local plan-making, the SPA must prepare a timetable to prepare its SDS, prepare and consult on a draft SDS, submit this for examination, undertake any necessary main modifications, send to the SoS and then adopt the SDS. There will be requirement to review it from ‘time to time’, but as yet no indication of what this means. Similarly to current plan-making, there is scope for the SoS to intervene at virtually all stages to direct an authority to prepare an SDS (or indeed, to stop any work on the SDS), make modifications, to adopt the SDS, alter the SDS after adoption and to review the SDS.

The SDS should address matters of ‘strategic importance’, including infrastructure and housing (this may include the type, quantum and/or distribution, including identifying general areas that are suitable for development) but should not make specific allocations. Like local plans, SDSs should have regard to their effects on sustainability, climate change and health.

The introduction of the NPPF in 2012 and revocation of Regional Spatial Strategies (RSSs) saw strategic planning wind down considerably, with this only taking place voluntarily where authorities were aligned with their neighbours in their vision for housing and infrastructure. We’ve seen joint plan-making in areas including in Greater Norwich, Central Lincolnshire, South Worcestershire, Cheltenham/Gloucester/Tewkesbury, North Essex and Plymouth/South West Devon. We’ve also seen a joined-up approach to plan-making (where local plans are produced separately, but with close collaboration and [importantly] agreement on key issues, and in some cases examined together) across areas like Greater Cambridge and – until recently – Oxfordshire. In some cases though, they have taken a really long time to prepare and adopt – nearly 10 years in the case of the Greater Manchester Spatial Framework (and even then, the plan saw Stockport withdraw, leaving the plan ultimately covering only 9 of the 10 Manchester authorities).

However, there have been far more areas where voluntary joint planning has not been taken up where, objectively, it was likely to have been necessary to address cross-boundary issues, including housing. The historic – voluntary - system neither required nor incentivised truly joint working and agreement, with little in the way of consequences for the ‘do nothing’ approach for authorities whether they were ‘exporters’ or ‘importers’ of development needs. This has typically been further complicated by the requirement for ‘unanimous’ support, leading to the unravelling of plans in areas where just one (or two) areas are not aligned with the vision for a wider plan.

The failure of joined-up plan-making has also often taken place in areas where high housing pressures meet significant planning constraints; Greater Brighton and Coastal West Sussex, Urban South Hampshire, Birmingham and the Black Country, South West Hertfordshire and South Essex (and more – with many areas failing to even see a plan get off the starting line). Indeed, we’ve seen some areas make attempts at joint planning only for those efforts to be abandoned where they lack unanimous support; the West of England Joint Spatial Plan (withdrawn in 2019), the Oxfordshire 2050 Plan (abandoned in 2022) and the Black Country Joint Plan (collapsed in 2022) to name just a few. We’ve even seen attempts by Central Government to initiate strategic planning, notably in the proposed OxCam Arc Spatial Framework, although this was significantly watered down and eventually abandoned by the-then Conservative Government in 2022.

If the last decade has taught us anything, it’s that genuinely effective joint working on a voluntary basis is – unfortunately – the exception, not the rule (particularly as this has required unanimous support, which has often been the hurdle in getting joint plans in place). This is a key lesson which we must learn from in order for strategic planning to be fully effective in the future. On the face it, the many and varied powers that the SoS has to force an SDS into existence and variation, including controlling the area to which it relates, suggests that there is perhaps more scope for this iteration to succeed. The shift from ‘unanimous’ to ‘majority’ (as proposed for SDSs) is also an important one.

The principle of SDSs – which will address strategic matters, primarily infrastructure and housing, which need to be considered across larger areas - will be one that is welcomed by many. But their effectiveness will be determined by a range of factors, namely whether: 

 

1. 1. They cover an appropriate geography where such matters can appropriately be assessed and addressed. Too small and they risk not being capable of properly addressing strategic matters, particularly in relation to infrastructure. Too large and there is a real risk of lacking agreement, as areas have different needs and priorities (in turn, creating delay and uncertainty). Of course, the question of geography will also inherently link to local government reorganisation (which we return to later) – albeit we expect the geographies to be established through a consultation process and, if necessary, the SoS will be able ‘patch’ areas together; and
       
   2. They are prepared quickly and with content which is proportionate to their objectives. Historically, strategic planning (whether driven by a top-down or bottom-up approach) has taken far too long and with strategic plans containing far too much material for their purpose. The London Plan provides a valuable lesson in this sense, with the London Plan Review Report of Expert Advisors recently noting the London Plan’s “excessive complexity and policy overload”[1]. SDSs must be kept as brief as possible whilst addressing the key strategic matters for their area, both to allow them to be prepared and adopted quickly and to avoid repetition of any material set out in national policy (including unlawful repetition of future National Development Management Policies) and material that should be within local plans. Indeed, our research insight ‘Spatial Awareness’ published in 2022[2] identified conciseness as being of key importance to the success of SDSs.

 

With history showing the voluntary strategic planning does not work in many parts of the country (albeit this has been in the context of requiring unanimous support, which is set to change), central to the establishment of SDSs will be the extent to which the SoS intervenes in the event that SDSs aren’t progressing in a timely manner or are too detailed.

Although intervention powers for local plans already exist, they were scarcely used by the previous Government, even in areas which chronically and repeatedly failed to take any action to prepare and adopt a plan. As of March 2025, over 100 – a third – of authorities have a plan which is more than 10 years old, of which around half of these have not adopted a plan since the introduction of the NPPF in 2012. Yet, there was only intervention by the previous Government in a handful of areas. A shift in approach to intervention powers from the current Government will be crucial in getting strategic planning up and running.

When thinking about the prospects for local plan-making, we have identified four important considerations:

With many parts of the country currently being asked to consider how to reorganise local government, there will remain – at least in the short term – uncertainty in some parts of the country on the area/s (authorities and geographies) which SDSs will apply to. Until such time as any reorganisation is complete, authorities of all types may find themselves unsure whether to progress local plan-making and/or SDSs (as applicable).

Government has made it clear that its objective is to “drive local plans to adoption as quickly as possible” and that “authorities without an up-to-date plan should not stop work on a plan”[3]. But historically, we have seen authorities pausing their plan-making process to await the outcomes of proposed planning reform[4], and the proposed introduction of SDSs (separate to the issue of local government reorganisation) could yield similar results. Authorities which think they may be subject to an SDS might pause their local plan-making efforts until that SDS is adopted, to avoid any abortive work on a local plan – albeit it could be possible that the SoS may intervene to require local plan-making to continue, given the clear expectations that have been set out by Government. In the event that plans are paused (particularly where the current plan is out-of-date), this might create a local plan ‘vacuum’, creating uncertainty; in highly constrained areas development is likely to slow significantly, and in less constrained areas this could yield a flurry of speculative non-plan-led development.

On the flip side, we may see authorities continue to progress with their plans, although the interaction between these local plans and any forthcoming SDS is unknown; indeed, it is likely to depend on the format and content of those SDSs. For example, will future SDS be drafted such that their strategic policies account for local plans which might have been recently adopted, thus not rendering those local policies superseded? Or might those SDSs have to set policies contrary to those local plans, rendering parts of them out-of-date?

For principal authorities (like unitary authorities) that already having plan-making functions preparation of an SDS will likely come naturally, but for most principle authorities this type of plan-making will be something new for which the authority won’t have a team of ready-made planners. The lack of planners is nothing new in the industry, so questions remain as to where these staff could come from, particularly given they will be needed relatively quickly. This may see new recruitment into the sector, but may also see planners seconded (from lower-tier, i.e. district councils) in order to support the principle authority preparing the SDS (albeit this may simply create knock-on effects, affecting capacity and plan-making function within those lower-tier areas).

The time taken to implement wide scale local government and planning reform, not to mention the general local plan-making cycle, is likely to be longer than a parliamentary term, and no doubt some authorities will be considering their future beyond the horizon of the current Government. This has been the case in the past; the concept of Regional Strategies (RSSs) was introduced in 2004 by the-then Labour Government, with some regions adopting a strategy in the following years (coverage was not universal). However, the subsequent election of the Conservative (and LibDem Coalition) Government in 2010 saw RSSs revoked, with a return to locally-led plan-making. Realistically, some authorities will be considering whether the next General Election might yield a new Government with different priorities for planning, and therefore whether to invest their efforts in local and/or strategic planning at this time, though the longevity of any planning reform will of course also depend on how changes are introduced and embedded into the system (with SDSs coming forward in primary legislation, rather than say secondary legislation or guidance).

Strategic planning has the potential to overcome some of the 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. But in order to be effective, Government must learn the lessons from past efforts in strategic planning, which have typically seen strategic planning take far too long to implement and have (largely) not worked when enacted on a voluntary basis. Things are – at least in the immediate term – made more complicated by the prospects of local government reorganisation, albeit in the long term having larger authorities may be conducive to strategic planning. Provided reorganisation can take place quickly, and that intervention powers related to strategic planning are used appropriately to ensure SDSs are prepared quickly and efficiently (and of course, assuming capacity within the profession to provide the planners needed to implement all of this), they could provide the mechanism for effective strategic planning that has been largely missing over the last 10-15 years.