In December 2025, the government did something it has not done for many years, proposing substantive changes to the built heritage policies of the National Planning Policy Framework.
Alongside the draft NPPF, an accompanying consultation document sets out the government’s rationale. At its core is an objective of:
“Taking a more positive approach to the use of heritage assets. We want a clearer and more positive approach which can better support suitable heritage related development, replacing the current policies that are difficult to navigate.”
The consultation commentary acknowledges that heritage policy has become one of the most complex areas for applicants and decision makers to deal with. It notes that existing policies have focused too heavily on addressing harm, and have not provided sufficient positive support for the sustainable reuse of heritage assets in a way that supports growth. The proposed changes are intended to strengthen the ability to bring forward heritage related development.
The broad ambition is a sensible one. The current heritage policies in the NPPF are long in the tooth and although broadly functional, are not without their issues.
A redrafting rather than a rewrite
At first glance, the heritage chapter in the draft NPPF can appear to be a complete rewrite. In reality, this is not the case. Much of the text has been rearranged, consolidated and tweaked.
For example, Policy HE2 introduces a dedicated section for World Heritage Sites and Conservation Areas, drawing together elements previously found in paragraphs 204, 219 and 220. Policy HE4, securing the conservation and enhancement of heritage assets, consolidates material from paragraphs 202, 209, 210 and 221. Overall, the thinking behind the changes is understandable and, in many cases, will assist with making policy clearer and easier to navigate.
This blog does not attempt a paragraph by paragraph comparison. Instead, it focuses on some of the key themes and what they may mean in practice for applicants and decision makers. In particular, it considers changes to concepts such as ‘less than substantial harm’, ‘great weight’, ‘optimum viable use’, the revised approach to non-designated assets, and whether the stated aim of a more positive stance which supports growth has been realised.
Moving beyond harm alone, being proactive and recognising the positive
The shift towards a more positive tone and a more proactive approach is notable.
Policy HE1 increases the responsibility for local authorities at the plan making stage. It requires councils to identify the main heritage features within the plan area, including those assets most at risk through neglect, decay or other threats, and to set out a positive strategy for their conservation and enhancement, including where these assets can be used to support sustainable growth.
This is not entirely new. Previous versions of the NPPF already required plans to set out a positive strategy for the conservation and enjoyment of the historic environment. However, the revised wording places greater emphasis on identifying solutions for assets at risk, particularly where heritage assets can support sustainable growth. As part of this, authorities will be expected to prepare a borough wide heritage statement and are encouraged to use tools such as design codes and masterplans.
Policy HE2 also states the need for periodic review of Conservation Areas. While this reflects existing statutory duties, the additional policy emphasis may help reinforce the importance of keeping evidence and boundaries up to date, even if progress remains constrained by resources.
Taken together, this more proactive approach could help establish a clearer baseline at plan making stage, providing a better starting point for guiding proposals and decision making. However, this may be challenging for under-resourced authorities, while some authorities already do much of this work.
A more positive tone is also evident at decision making stage. For the first time, the heritage policies of the NPPF explicitly identify several scenarios in which development “should be approved”. Examples include proposals that would have a positive effect on designated or non-designated heritage assets, or proposals that preserve those elements of the setting of a World Heritage Site or Conservation Area that make a positive contribution to significance.
The unwritten subtext, of course, is that approval remains subject to consideration of all other relevant heritage and planning matters. Nonetheless, these provisions provide helpful policy hooks, emphasising the weight to be afforded to heritage benefits. They also address a tendency in practice for decision making to focus heavily on harm, while positive heritage effects receive less explicit recognition.
Policy HE6(3) also provides, for the first time, examples within the NPPF of “important public benefits”, including securing the long-term reuse of a vacant or underused Listed Building, and enabling energy efficiency and low carbon heating measures. While not exhaustive, this is helpful, and may encourage decision makers to attach more weight to these benefits, which often necessitate some degree of heritage harm.
Taken together, these changes point towards a slightly more positive and proactive policy framework, both at plan making and decision making stages.
Harm, weight and decision making
Despite this shift in tone, the core decision-making framework remains broadly familiar. That said, there are some notable changes.
The distinction between harm that is substantial and harm that is not substantial remains, although the phrase “less than substantial harm” has been dropped. “Substantial harm” is defined for the first time, as harm which would “seriously affect a key element of the asset’s significance”. This reflects a position that has largely been settled through case law and is set out in current guidance, but its inclusion in policy is nonetheless helpful.
The removal of the “less than substantial harm” label appears intended to move away from confusing terminology, and to encourage clearer articulation of the nature and degree of harm below the substantial threshold. While the policy does not introduce a formal sliding scale below the substantial threshold, the requirement to describe harm more precisely is now embedded in policy rather than guidance.
The draft also replaces the long-established requirement to give “great weight” to the conservation of designated heritage assets with “substantial weight’, a change now expressed in Policy HE6. The consultation document explains that this is intended to improve consistency across the Framework rather than to signal any reduction in the weight to be applied, and a footnote reinforces the continued relevance of the statutory duties.
On one level, this can be seen as a matter of tidying up. However, the wider use of the term substantial weight elsewhere in the Framework, including (for example) in relation to housing delivery, town centre vitality and energy efficiency, may influence how decision makers perceive the relative balance between competing considerations. In finely balanced cases, this could affect outcomes, even if the underlying legal position remains unchanged.
The removal of the concept of “optimum viable use” is also notable. This has historically been used to assess whether works to a heritage asset could be justified by securing its least harmful, but still economically viable use, particularly where assets are vacant or at risk. While useful in some cases, it can be difficult to apply if interpreted in the strictest sense. Its removal may therefore allow greater flexibility where harm is not substantial, and simplify the balancing exercise.
Other changes largely reflect guidance and established practice. There is now an explicit requirement to avoid or minimise harm, and a stated focus on considering the effects on significance rather than the scale of development. It is clarified that World Heritage Site management plans should be considered where relevant.
One area of concern is Policy HE5.4, which requires decision makers to be satisfied that heritage assessments “accurately reflect” effects. This could prove problematic where a robust Heritage Impact Assessment reaches conclusions that differ from an officer’s judgement. It risks encouraging litigation rather than substantive debate, and leaves no room for professional disagreement. This sentence would benefit from refinement or removal.
Non designated assets - a subtle but important shift
The redrafted policies significantly reduce the distinction between the approach to designated and non-designated heritage assets.
In particular, concepts such as ‘substantial harm’ and ‘clear and convincing justification’ apply across both categories. It is not entirely clear whether the changes represent a genuine increase in protection, or simply a streamlining of policy. The truth is perhaps somewhere in between.
Most notably, Policy HE7 introduces a standalone balancing exercise for non-designated heritage assets. Previously, the effect on such assets was simply to be taken into account within the wider planning balance. The revised policy now requires harm to non-designated assets to be outweighed by the benefits of the proposal. Notably, this refers to “benefits”, rather than “public benefits”, although in practice the distinction may be limited.
The practical impact of this change remains to be seen, but it certainly seems to place greater emphasis on minimising and justifying harm to non-designated heritage assets, and could influence outcomes in some cases.
What is likely to change in practice?
Overall, while there is a lot of ‘red pen’, the effects of the changes are generally subtle. Many clarify existing practice, improve consistency, and make policy easier to navigate, rather than fundamentally altering outcomes. In many cases, the impact will be felt more in how Heritage Impact Assessments are expressed, rather than in the fundamental approach to conservation.
That said, the changes around substantial weight, the removal of optimum viable use, the more explicit recognition of positive effects may influence balancing exercises and decisions at the margins.
The enhanced expectations placed on local authorities at plan making stage could be beneficial, but will be resource intensive.
There is also a clear, if modest, shift in emphasis towards non-designated heritage assets.
Overall, the changes appear evolutionary rather than revolutionary, collectively nudging the framework towards greater clarity and a slightly more positive, proactive approach.
However, the requirement for decision makers to agree with the conclusions of Heritage Impact Assessments, remains a concern.
Extending statutory duties
Finally, the consultation document raises the possibility of extending the statutory special regard duties beyond Listed Buildings and Conservation Areas to include World Heritage Sites, Registered Parks and Gardens, Protected Wrecks and Scheduled Monuments.
If implemented, this would introduce a clear legal duty to have special regard to these assets rather than relying solely on policy. While this may not significantly change outcomes in many cases, it would provide greater clarity and consistency and help address some of the unevenness between asset types.
