But what about a potential housing development over 500m away from the edge of the park gardens and invisible from the house?
The High Court quashed a planning permission in the July 2017 case of Steer v Secretary of State for Communities and Local Government, for 195 houses near Kedleston Hall in Derbyshire. The site of the Curzon family home since they arrived with William the Conqueror, the now National Trust property is indeed magnificent and deserving of the highest level of protection.
The developer's original proposal was rejected so it submitted a revised, smaller scheme of 195 houses adjacent to existing housing on three sides and over 500m away from the parkland at the nearest point. The proposed development site was also already screened by a thick row of trees from Kedleston Hall. The application had been appealed by the developer and granted by the Inspector.
The National Planning Policy Framework (NPPF) states:
"132. When considering the impact of a proposed development on the significance of a designated heritage asset, great weight should be given to the asset's conservation. The more important the asset, the greater the weight should be. Significance can be harmed or lost through alteration or destruction of the heritage asset or development within its setting."
The Inspector had clearly considered the physical and visual impact on Kedleston Hall. The conclusion was that the impact would have been less than substantial. If the tree-screening was removed in the future, the new housing would mean a view to the Hall would have been lost, However, the view from the Hall would be little changed. The Inspector held that the effect on the significance of Kedleston Hall was negligible.
The Inspector's decision was judicially reviewed by a local resident. Historic England joined in as an interested party.
The judge found that the Inspector had erred in not giving a wide enough consideration to the setting of Kedleston Hall and quashed the appeal decision. The judge summarised the claimant's evidence as:
"[The] appeal site was part of the setting of the Hall because it had formed part of the estate, managed historically as an economic and social entity, and it remained in its historic agricultural use, with hedges and mature trees characterising the field boundaries. From the Hall and the Park, the surrounding rural context was important in preserving a sense of a parkland landscape at the centre of a managed rural estate, rather than in a suburban context."
The judge held that the Inspector had focussed on the visual connection and impact of the proposed development and had set aside the social and economic connections of the appeal site to the setting of the Hall. The judge emphasised that the National Planning Policy Guidance states that:
"Although views of or from an asset will play an important part, the way in which we experience an asset in its setting is also influenced by other environmental factors … and by our understanding of the historic relationship between places. For example, buildings that are in close proximity but are not visible from each other may have a historic or aesthetic connection that amplifies the experience of the significance of each."
It should also be remembered that the NPPF allows for a cumulative effect of development to be taken into account. The proposed site was already adjacent to existing housing on three sides. Historic England's original response to the application mentioned that the development on the fringes of Derby was at a "tipping-point in safeguarding the setting" of Kedleston Hall and its parkland. The implication was that this development was the straw that broke the camel's back.
In summary, for development near a site that has the highest designation of protection under domestic or European environmental and planning laws, developers and local planning authorities should consider the impact of the development on visual/physical grounds and also social/economic/historical relationship grounds. Further, the fact that other development has occurred nearby may not be of assistance as a precedent - it might in fact hinder the application as the cumulative effect can be taken into account.