The next London Plan and the delivery gap
by David Maddox, Founder
Published 26 June 2026
London’s housing challenge has never been short of ambition. The difficult part is turning that ambition into permissions that can be implemented, funded and built.
That is the setting for the next London Plan.
The GLA’s engagement material confirms that the new London Plan is expected to run from adoption in 2027 to 2050. For housing targets, it will run from 2026/27 for 10 years. That longer horizon matters because many of the measures needed to increase housing supply, including major infrastructure, growth locations and changes to development capacity, take years to plan and deliver.
The housing need figure is stark. The GLA says London’s housing need is 87,992 new homes per year. It also notes that the London Plan sets housing targets for each borough based on where homes can be built, rather than simply where need arises locally, because London is treated as one large housing market for planning purposes.
That creates a strategic planning problem that is more complex than a single annual target.
London needs more homes. But it also needs those homes to be capable of delivery in a market where viability is under sustained pressure. Construction costs, finance costs, land values, affordable housing requirements, design standards, building safety requirements, infrastructure contributions and sales risk all influence whether a consented scheme can proceed.
This is where the next London Plan becomes commercially significant.
If strategic policy increases housing expectations without creating a realistic route to delivery, more sites may become trapped between policy ambition and development economics. That is particularly relevant for higher-density residential schemes, estate regeneration, town centre intensification, brownfield redevelopment and mixed-use sites where abnormal costs, phasing constraints, existing uses or infrastructure requirements already affect viability.
For too long, housing delivery has sometimes been discussed as if the planning issue ends once capacity is identified. It does not. A site may be suitable for residential development in principle, and may even be capable of accommodating significant density in design terms, but still fail to come forward if the overall policy burden and market conditions do not support implementation.
That is the delivery gap.
The Mayor’s adopted Support for Housebuilding London Plan Guidance is an important short-term response to that problem. It introduces time-limited changes to cycle parking requirements, changes to housing design guidance and a new time-limited planning route for affordable housing. The stated purpose is to make housebuilding more viable, provide momentum to stalled sites and increase housing delivery while maximising affordable housing in the current challenging context.
The guidance is also notable because the affordable housing route departs from Policy H5 of the current London Plan, which provides the threshold approach to planning applications. City Hall describes it as an additional time-limited emergency route intended to bolster housing delivery in challenging economic conditions.
That is a significant planning signal. It recognises that the existing framework is not simply operating in normal market conditions. It also recognises that some policy requirements, however well intentioned, may affect deliverability if they are applied without sufficient regard to current development economics.
But the guidance should not be confused with the next London Plan.
The adopted guidance is a short-term intervention. It is time-limited, does not form part of the development plan, and is intended to respond to the current emergency situation in housing delivery. The next London Plan will be the more important medium-term framework for borough targets, spatial strategy, density expectations, affordable housing policy, design standards and the treatment of constrained sites.
That distinction matters for developers and landowners.
The support guidance may assist some schemes now, particularly where cycle parking, housing design guidance or affordable housing requirements are affecting viability. But land promotion, acquisition, design strategy and planning submissions over the next few years will also need to anticipate the direction of the emerging London Plan. Sites being appraised now may move through the planning system during a period of policy transition.
The strongest planning strategies will therefore be those that connect policy compliance with deliverability from the outset.
That means capacity testing should not be limited to what can be drawn on a plan. The more important question is whether the proposed capacity can be achieved with an acceptable design, realistic tenure mix, credible construction assumptions, suitable infrastructure provision and a viable affordable housing position.
Affordable housing strategy will need to be considered early. The emergency route may be relevant to some schemes, but it should not be treated as a substitute for a robust long-term planning strategy. If a scheme depends on a particular affordable housing position, that case needs to be grounded in evidence and aligned with the likely direction of policy, not introduced late in the process as a viability correction.
Design standards and viability will also need to be assessed together. Where a scheme relies on flexibility, relaxation or a particular interpretation of guidance, that should be explained clearly and tied back to delivery. It is much harder to justify flexibility if it appears to be a late-stage value engineering exercise after the main design decisions have already been fixed.
Borough-level implications will be equally important. The next London Plan will shape how housing need is distributed and how growth is directed. That may affect Opportunity Areas, town centres, suburban intensification, industrial land, estate regeneration and potentially more difficult questions about land beyond London’s existing urban area. The current engagement material expressly includes issues such as brownfield-first growth, Opportunity Areas, town centres, industrial land, wider urban and suburban London, Metropolitan Open Land and large-scale urban extensions in the Green Belt as part of the discussion on increasing housing supply.
Those are not abstract plan-making questions. They affect site value, acquisition risk, promotion strategy, design parameters, infrastructure assumptions and programme.
For landowners, a theoretical capacity figure may become less useful if it cannot survive design review, affordable housing negotiation, infrastructure requirements and market testing. For developers, a planning submission will need to show not only that the site can contribute to housing supply, but that the proposed form of development offers a realistic route to delivery. For professional advisers, the key risk is timing: schemes conceived under one policy and market assumption may be determined under another.
That does not mean applicants should wait for the new London Plan before progressing sites. In many cases, delay may increase rather than reduce risk. But it does mean that evidence needs to be prepared in a way that can withstand a changing policy environment.
A good planning case will need to explain why the proposed density is appropriate, how the design responds to the site and its surroundings, what affordable housing position is realistic, where viability constraints sit, how infrastructure and environmental requirements are addressed, and why the scheme is capable of being delivered.
The planning system does not need lower ambition for London housing. It needs a better connection between ambition and implementation.
That is the real test for the next London Plan. The question is not simply whether London can identify a high level of housing need. It clearly can. The harder question is whether strategic policy can align housing need, affordable housing, design quality, infrastructure and viability in a way that enables homes to be built.
For applicants, the lesson is clear. The next generation of London residential schemes will need more than a capacity argument. They will need a delivery argument.
The question will not simply be: how many homes can the site accommodate? It will be: what form of development can realistically secure permission, satisfy policy expectations and proceed to delivery?