Planning obligations after the 2026 NPPF: earlier certainty but reform still incomplete
by David Maddox, Founder
Published 24 August 2026
The 2026 NPPF does not remove negotiation from planning obligations or viability. It changes where that negotiation is expected to happen.
That distinction matters. The direction of travel is towards a system in which affordable housing and infrastructure contributions are established more clearly through the development plan, tested for viability at that stage and then reflected in land values. By the time a planning application is submitted, the starting assumption should increasingly be that those requirements are known and deliverable.
In practical terms, planning-obligation risk is moving earlier in the development cycle.
PM12 is central to that shift. Plans are expected to establish clear and deliverable requirements for affordable housing and infrastructure contributions, with those requirements capable of being taken into account in land values. DM5 then reinforces the position at application stage by assuming that schemes which comply with up-to-date contribution policies are viable, except in identified circumstances where a site-specific viability assessment may still be justified.
The important consequence is not that viability has disappeared. It is that the basis for reopening policy requirements becomes narrower and more specific.
A developer arguing at application stage that a policy-compliant scheme cannot support the required level of affordable housing or infrastructure contribution will need to explain why the plan-level assumptions should not apply to that particular development. That may be because the site or development is materially different from the typologies tested when the plan was prepared, because relevant costs were not accounted for, or because circumstances have changed sufficiently to justify a fresh assessment.
The argument therefore starts earlier than the appraisal submitted with the planning application. It starts with the evidence that informed the plan.
That gives plan-level viability work greater commercial significance. Developers, landowners and site promoters will need to pay closer attention to the assumptions being used to demonstrate that emerging policy requirements are deliverable. A contribution level that appears manageable when tested against a generic typology may become much more difficult once abnormal costs, infrastructure constraints or site-specific characteristics are understood.
If those differences are not identified until after a site has been acquired, the planning system is increasingly unlikely to treat the purchase price as a reason to reduce policy requirements.
This is where the reform becomes particularly relevant to land transactions. Planning due diligence cannot stop at identifying the headline affordable-housing percentage or known section 106 requirements. Purchasers need to understand the assumptions beneath those policies and whether the site they are buying genuinely resembles the development that was tested.
The NPPF is, in effect, reinforcing the principle that policy-compliant obligations should influence land price, rather than land price determining what obligations a development can afford.
That should create greater certainty if the system works as intended. But certainty at application stage depends on good decisions being made earlier.
The same shift can be seen in DM1. For major applications, applicants are expected to explain their proposed planning obligations, with early engagement encouraged between applicants, local authorities, infrastructure providers and registered providers.
That has practical implications for pre-application strategy.
Heads of terms should be less of a late-stage exercise and more closely connected to early scheme design and deliverability. On residential schemes, for example, engagement with registered providers may reveal whether the affordable-housing assumptions underpinning a scheme work in practice. Infrastructure requirements may have implications for phasing, costs or design that are better understood before an application is substantially fixed.
Early engagement will not remove disagreement. Its value is that it should expose disagreement sooner.
That is a recurring theme in the new framework. The government is not trying to eliminate planning judgement from obligations; it is trying to reduce the amount of fundamental negotiation that happens after an application has already been designed, priced and submitted.
DM6 supports the same direction by stating that planning obligations should only be used where conditions cannot address unacceptable impacts. Alongside that sits the government's wider intention to standardise parts of the section 106 process.
But this is where the reform remains incomplete.
The NPPF policies took effect on 17 August 2026, yet some of the mechanisms intended to support the new approach are still to come. The government intends to consult on a standard section 106 template for medium development, defined as schemes of 10–49 homes on sites of up to 2.5 hectares. Further guidance is also expected on affordable-housing commuted sums and viability, alongside a review of the statutory framework for modifying obligations under section 106A.
As at 24 August, there is therefore a gap between the policy direction and the tools intended to implement it.
Medium-site applicants in particular should be careful not to confuse an intention to standardise with an existing national standard form. Local drafting and negotiation remain relevant until further reforms are actually introduced.
That transitional position is important because the 2026 NPPF could otherwise be read as though the section 106 system has already become more fixed than it really has.
The more significant change is subtler. Planning-obligation risk is being redistributed.
If application-stage viability becomes less routine, developers have a stronger reason to scrutinise emerging policies and viability evidence during plan-making. If contributions are expected to be reflected in land values, purchasers need to understand them before agreeing a price. If major applications are expected to set out obligations earlier, heads of terms and affordable-housing delivery need to become part of pre-application strategy rather than an issue left for the end of the process.
That may reduce some late negotiation, but it also raises the cost of getting the earlier stages wrong.
A weak plan-level viability assumption may carry greater consequences once adopted. A purchaser who fails to identify an abnormal cost may have less room to rely on viability later. A scheme designed without early consideration of affordable-housing delivery or infrastructure obligations may need more significant revision before determination.
The lesson from the new NPPF is therefore not that section 106 negotiation is ending.
It is that the planning system increasingly expects the difficult questions to have been asked sooner.
For developers and landowners, that means testing policy-compliant obligations against the plan evidence before acquisition, identifying departures from plan-level assumptions early and bringing likely planning obligations into scheme strategy from the outset.
Greater certainty may be the objective. But the price of that certainty is that planning judgement, viability evidence and commercial assumptions all need to come together much earlier than they sometimes have before.