Heritage and growth under London Plan Policy HC1
HC1 asks applicants to describe significance and show the asset can still be appreciated in its surroundings. The statutory duties sitting alongside it are stronger, and a finding of harm carries real weight.
Policy HC1 of the London Plan asks applicants to do two things that are easy to state and hard to do well: identify the significance of the heritage assets affected, and show that the proposal conserves that significance while allowing the asset to be appreciated in its surroundings. The policy sits alongside the statutory duties rather than replacing them, and in a London scheme it is usually the framing document rather than the deciding one.
Where it earns its place is in the growth half of its title. HC1 is written on the premise that heritage conservation and intensification can coexist, and it expects boroughs to maintain the evidence base, including conservation area appraisals and local lists, that makes that possible. For a consultant assembling a case, the policy is the hook on which the whole heritage narrative hangs.
What the policy asks of a development proposal
Three obligations fall on the applicant. Describe the significance of any heritage asset and its setting affected by the proposal, in a level of detail proportionate to the asset. Demonstrate that the proposal is sympathetic to that significance. And show that the asset can still be appreciated within its surroundings after the development.
That third limb is the one most often skipped, and it is distinctively a London concern. A listed church that remains physically untouched can still be harmed where new development removes the views from which it was designed to be seen, or encloses it so that its scale no longer reads. Setting is not a buffer zone around an asset, it is the surroundings in which the asset is experienced, and the question is always what the surroundings contribute to significance.
The statutory duties operate in parallel and they are stronger. Sections 16 and 66 of the Planning (Listed Buildings and Conservation Areas) Act 1990 require special regard to the desirability of preserving a listed building, its setting and features of special interest. Section 72 requires special attention to the desirability of preserving or enhancing the character and appearance of a conservation area. The Court of Appeal in Barnwell Manor confirmed that the section 66 duty requires considerable importance and weight to be given to the desirability of preserving the setting of a listed building, which means a finding of harm carries real weight rather than sitting level with other considerations.
Identifying significance before the design
Significance assessment has to come before the design, not after it. Where it comes after, the statement reads as a justification, and officers can tell.
The sequence that works on a London site with multiple assets is this.
- Identify every asset that could be affected, designated and non-designated, within a defensible study area
- Research each one, using the list entry, the Historic Environment Record, historic maps and the borough's conservation area appraisal
- Articulate significance by heritage interest, saying what the asset is valued for rather than describing it
- Identify which parts of the setting contribute to significance, and which are neutral or detract
- Test massing options against that analysis and record the ones rejected
- Only then assess the effect of the chosen scheme
Step 5 is what turns a statement into evidence. A scheme that can show three massing studies, two of which were rejected because they obstructed a designed view, has demonstrated that the design responded to significance. Keep the rejected options in the appendix.
Historic England's advice on statements of heritage significance and on managing change within the setting of heritage assets provides a method that London boroughs recognise, and using it saves arguing about the approach.
The harm tests and how they are applied
The National Planning Policy Framework, in the edition published on 17 August 2026, retains the structure that has governed these decisions for over a decade. Great weight is given to the conservation of designated heritage assets. Substantial harm to or total loss of a highly graded asset requires circumstances that are wholly exceptional. Less than substantial harm is weighed against the public benefits of the proposal. Harm to a non-designated asset calls for a balanced judgement having regard to the scale of harm and the significance of the asset.
In London the practical application has two features worth planning for. First, the public benefits side of the less than substantial harm balance is usually populated with housing delivery, affordable housing and street improvements, and the weight given to housing numbers varies between boroughs and inspectors. Set the benefits out with evidence rather than as assertions, and quantify them.
Second, cumulative harm is a live issue in areas under sustained development pressure. Where several consented schemes have each caused low level harm to the same conservation area, the next application faces an argument about the combined effect. Deal with it by describing the baseline as it now is, including consented but unbuilt schemes, rather than as it was when the conservation area was designated.
| Finding | Policy consequence | What the applicant must supply |
|---|---|---|
| No harm | Policy test passed, conservation duties satisfied | Significance analysis supporting the conclusion |
| Less than substantial harm | Weighed against public benefits | Harm characterised by degree, benefits quantified |
| Substantial harm, designated asset | Only the narrowest circumstances suffice | Rarely achievable, reconsider the scheme |
| Harm to non-designated asset | Balanced judgement | Evidence the asset meets local list criteria or not |
Characterise the degree of harm yourself. A statement that concludes less than substantial harm without saying where in that range the proposal sits leaves the officer to pick a point, and they will pick a less favourable one.
Non-designated assets on a borough local list
Most London boroughs maintain a local list of buildings of merit, and the criteria for inclusion are published. Those criteria matter in two directions. Where your application affects a locally listed building, the criteria tell you what the borough values about it. Where an objector asserts that an unlisted building is a non-designated heritage asset, the criteria are how you test the claim.
A building is not a heritage asset because somebody likes it. The question is whether it has a degree of heritage interest meriting consideration in planning decisions, and the borough's own criteria are the best available evidence of that. Where a building fails those criteria, say so with reference to them. Where it meets them, accept it and assess the harm properly, because resisting the designation and then losing the point costs credibility on everything else.
Public houses are a recurring example in London, where the building, the use and the community value are often conflated in objections. The analysis required for protecting public houses in a London application separates those strands.
Archaeology and the built heritage overlap
Greater London has a tiered system of Archaeological Priority Areas, maintained with Historic England's London advisory service, and the tier tells you what level of response is expected. A site in a higher tier will normally need an Archaeological Desk-Based Assessment with the application, and often a field evaluation before determination rather than by condition.
The overlap with built heritage is practical. Basement excavation beneath a listed building raises listed building consent questions about the historic fabric and archaeological questions about what lies beneath it, and the two sets of evidence are gathered by the same opening-up works. Co-ordinate them. A single investigation designed to answer both questions costs less than two and produces a more coherent story.
Where standing fabric will be lost, historic building recording and archaeological recording can be specified together in one written scheme of investigation, which is how most London boroughs prefer to condition it.
Townscape evidence that supports the case
For a tall or large building the heritage case is won or lost on views. A Townscape and Visual Impact Assessment with accurate verified views is the evidence that converts a written significance analysis into something a committee can assess.
Four points on method. Agree the viewpoints with the borough and, where strategic views are engaged, with the relevant authority, before the photography is commissioned. Use verified rather than illustrative montages for any view that matters. Include the cumulative view with consented schemes modelled. And photograph in the season that shows the worst case, which for a view filtered by trees means winter.
The strategic views policies and the London View Management Framework behind them set out protected vistas with their own geometry and assessment requirements, and a scheme that intrudes into one needs that assessed separately from the general townscape work. Where the site sits near a World Heritage Site, the separate policy for those assets applies and the assessment has to address attributes of outstanding universal value, which is a different vocabulary from ordinary significance analysis.
Structuring the statement for a London scheme
A Heritage Statement for a London application should run in a fixed order: the assets and the study area, the significance of each, the contribution of setting, the design evolution with rejected options, the assessment of effect asset by asset, the characterisation of harm, the public benefits, and the policy conclusion against HC1, the statutory duties and the Framework in turn.
Keep the policy conclusion last and keep it short. Officers read the significance section and the harm characterisation closely and skim the rest. Where the scheme also relies on intensification arguments, the relationship between heritage constraint and optimising site capacity should be explained in the design material rather than left for the committee to infer.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
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Frequently asked questions
What does Policy HC1 require an applicant to do?
Describe the significance of any heritage asset and its setting affected by the proposal, in detail proportionate to the asset, show that the proposal is sympathetic to that significance, and show that the asset can still be appreciated within its surroundings. The third limb is the one most often omitted from statements.
How much weight does harm to a listed building's setting carry?
Considerable importance and weight, following the Court of Appeal decision in Barnwell Manor on the section 66 duty in the Planning (Listed Buildings and Conservation Areas) Act 1990. The balancing exercise therefore starts from a strong presumption in favour of preservation.
Should I characterise the degree of less than substantial harm?
Yes. A statement that concludes less than substantial harm without saying where in that range the proposal sits leaves the officer to choose a point, and they will usually choose a less favourable one. State the degree, explain the reasoning, and quantify the public benefits set against it.
How do I test a claim that a building is a non-designated heritage asset?
Against the borough's published local list criteria, which are the best available evidence of what the authority values. Where the building fails those criteria, say so with reference to them. Where it meets them, accept the designation and assess harm properly rather than losing the argument and your credibility with it.
What archaeological evidence does a London site need?
The tier of any Archaeological Priority Area covering the site indicates the expected response. Higher tiers normally require a desk-based assessment with the application and often a field evaluation before determination rather than by condition. Co-ordinate archaeological and built heritage investigation, since both usually need the same opening-up works.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.