Following the revised Planning Practice Guidance (PPG), which was issued on 23 July 2019, Chris Surfleet, Head of Heritage and Urban Design Studio, explains why the key refinements are welcomed.

The latest set of revisions to the PPG include some important changes to key elements of the guidance relating to heritage assets.

Each element is likely to be relevant to existing projects and in some cases, could be of considerable influence. The key issues, which have received a tweak in the PPG, are under the following topics:

  • Assessing impact (paragraph 18)
  • Non-designated assets (paragraphs 039 and 040)
  • Optimum viable use (paragraph 015)

Assessing impact (paragraph 18)

As one of the most critical paragraphs in the PPG, which helps to apply the policies of the National Planning Policy Framework (NPPF), the guidance is now very clear that the terms of “substantial harm” and “less than substantial harm” should be thought of as categories of harm rather than an absolute description of harm level.

In the revised document it now states that:

“Within each category of harm (which category applies should be explicitly identified), the extent of the harm may vary and should be clearly articulated.”

This additional wording is important as it alludes to the so called sliding scale of harms, which Bidwells already applies in its Impact Assessment methodology, whereby levels of impact are graded according to their effects on heritage assets or their settings. Being able to explain and ‘grade’ levels of impact is important for applying such impact in the overall planning balance; for example, being able to assign a minor level of harmful impact may be an important articulation of measurement of that impact where such a minor level of harm could be outweighed by other public benefits.

In our opinion,  it is a very useful clarification of how the NPPF policies should be applied.

Non-designated assets (paragraphs 039 and 040)

The July amendments to the PPG include a greater obligation for planning authorities to designate so-called non-designated heritage assets, for example, those heritage assets not holding sufficient merit for statutory protection, but holding a degree of interest for which paragraph 197 of the NPPF applies.

The PPG is now clear that:

“only a minority [of buildings] have enough heritage significance to merit identification as non-designated heritage assets”.

This brings a higher degree of selectivity to the category.

The PPG now also includes the impetus for local planning authorities (LPAs) to:

“make clear and up to date information on non-designated heritage assets accessible to the public to provide greater clarity and certainty for developers and decision-makers.”

Whilst there will always be circumstances where issues of non-designated heritage assets arise during pre-application or application processes, the PPG is helpfully placing greater emphasis on planning authorities to help reduce the risks that can otherwise occur from ‘surprise’ designations.

This is another important addition to the PPG and should help to flush out such issues earlier in the planning process.

Optimum Viable Use (OVU) (paragraph 015)

The PPG has slightly helped with proving OVU and clarifying that OVU can at least be considered to be one of the economically viable uses (new word ‘economically’).  This means that the OVU is simply not the use that causes the least harm to an asset, but that it can indeed make viable financial sense too.

Whilst this is a subtle clarification of a difficult area, the wording prior to this did not make it clear that the OVU also needed to be economically viable and therefore this amendment to the guidance is also helpful.  Our view is that the revised amendments will have immediate relevance to several current projects.


If there are any questions relating to the above, or any other aspect of the current heritage policy or guidance, please contact us for more details.

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