Appeal 6004198

The appeal is dismissed.

My external inspection of the appeal property from [address] indicated that it has yet to be converted so as to be occupied as two separate flats. Nevertheless, the extensions to the property described in the permitted description of development are – at least to the front and side of the property – substantially complete. I shall thus determine the proposal on a part-retrospective basis.

The effect upon the Chiltern Beechwoods Special Area of Conservation (the SAC).

The site lies within the 12.6km Zone of Influence (the ZoI) associated with the [name] and Woods Site of Special Scientific Interest, which comprises a component of the SAC. The Conservation of Habitats and Species Regulations 2017 (as amended) (the Habitat Regulations) require that, where a project is likely to have a significant effect on a European site – either alone or in combination with other plans or projects – the competent authority must undertake an Appropriate Assessment of the implications of the proposal in view of the relevant site’s conservation objectives. For the purposes of this appeal, I am the competent authority.

The main qualifying features of the relevant component of the SAC are its extensive native beech forests on neutral to rich soils, its semi-natural dry grasslands and scrub on chalk, and its stag beetle population – a species of international importance. A threat to the integrity of the SAC arises from increased public access and recreational activities associated with additional development.

The current proposal follows the grant of planning permission in July 2021 (the original permission) for extensions to a dwelling in association with its conversion into two flats. This permission pre-dates the emergence of technical evidence regarding the impacts of recreational pressure on the SAC, which subsequently informed the delineation of the ZoI.

The proposal subject to this appeal seeks to vary the approved plans condition in order to regularise amendments to the building’s approved elevations. The approved plan ACFE/05A would be superseded by revised plan ACFE/05D. These changes have been pursued in the interests of achieving consistency across the elevations – most particularly at roof level – and ensuring compatibility with development as constructed.

It has been contended, particularly in light of the original permission and its past commencement, that the appeal scheme would not give rise to an increase in the number of residents within the ZoI. However, given that amendments to the elevations are required in order to achieve an appropriate correlation between them, it has not been demonstrated that the original development proposal, in its unamended form, was capable of lawful implementation. In this context, the original permission cannot be relied upon to establish the delivery of a net-additional dwelling. Furthermore, for the avoidance of doubt, and on the basis that the conversion of the appeal property into two flats constitutes an integral component of the original permission, a householder application would not represent an appropriate mechanism by which to regularise changes to the elevations.

Reference has been made to the Chilterns Beechwoods Special Area of Conservation Recreational Pressure Mitigation Strategy (August 2024) (the RPMS) in support of the argument that the disputed condition does not go to the heart of the permission. However, the original description of development encompasses not only the conversion of the dwelling into two flats, but also the associated extensions. The disputed condition, which specifies the approved plans, relates to details fundamental to the acceptability of the development as a whole.

In light of the above considerations, it is my judgement that varying the disputed condition as proposed would reasonably be expected to result in an increase in the residential population likely to utilise the SAC for recreational purposes. Consequently, the proposal would give rise to a likely significant effect on the qualifying features of the SAC. For the avoidance of doubt, whilst it is noted within the Council’s Delegated Report that officers initially considered that the proposal would not impact the SAC, this did not prejudice the Council’s determination of the application. In any event, I have considered all relevant evidence before me in reaching my own conclusions.

The RPMS, prepared in consultation with Natural England, identifies the requirement for qualifying development to mitigate increased recreational pressure through two mechanisms: [name] and Monitoring (SAMMS) within the SAC, and the provision of Suitable Alternative Natural Greenspace (SANG) to divert recreational activity away from the SAC. The appellant has not sought, by way of legal agreement, either a proportionate financial contribution towards SAMMS or the provision of SANG. In the absence of such mitigation, the proposal would cause harm to the integrity of the SAC.

Accordingly, the proposal conflicts with Policy NE1 of the Vale of Aylesbury Local Plan (September 2021), Policies EN1 and EN2 of the [site address] Neighbourhood Plan (August 2018), and the policies of the National Planning Policy Framework (December 2024) (the Framework) relating to the conservation and enhancement of the natural environment. These policies collectively require that nationally protected SSSIs are protected, and that development likely to affect the SAC will be subject to assessment under the Habitat Regulations and will not be permitted unless any significant adverse effects can be fully mitigated.

Whilst the intended variation of the disputed condition would effectively deliver a net-additional housing unit in the context of an acknowledged housing land supply shortfall, the application of the Framework’s policies that protect habitats sites provides a strong reason for refusing planning permission. Accordingly, the presumption in favour of sustainable development is not engaged. Moreover, the proposal conflicts with the development plan, and material considerations do not lead me to a decision otherwise.

For the above reasons, the appeal is dismissed.