Appeal 6005213

The appeal is dismissed.

I have used the description of the proposal as set out in the Council's decision notice, which is more accurate than the description used in the application form, including that ‘up to’ three dwellings are proposed. I am satisfied that no party would be prejudiced as a result.

The application is in outline, with details of the access to be considered at this stage. As such, matters of appearance, landscaping, layout and scale are reserved for future application. Layout plans were submitted with the application showing the possible siting of three dwellings. An alternative plan has been provided at appeal stage, showing only two dwellings. Given the outline nature of the application, and the broad description of development, I shall take the revised layout plan into account. Nevertheless, I have treated the plans as being illustrative, other than in respect of access.

At appeal stage, a signed and dated planning obligation [name] (UU) was submitted by the appellant. Amongst other things, this makes provision for the proposal to be developed as self-build and custom housebuilding (SBCH). This is a matter that I shall consider below.

The main issues are: • the effect of the proposal on the character and appearance of the area, including the setting of the former [name], listed at [name], • the effect of the proposal on highway safety, • whether sufficient information has been provided to show that the biodiversity net gain objective is capable of being met, and • the effect of the proposal on the living conditions of the occupiers of dwellings at numbers 5, 7 and [address] (Nos. 5 to 9), and at numbers 3 and 4 Louvain1 (Nos. 3 and 4) in respect of light, outlook and privacy.

The appeal site lies within an area of predominantly residential properties of relatively high density. It consists of sloping, largely undeveloped land, bounded by stone walls and railings. Not far from the site is the main building of the [name]. It was originally a Victorian workhouse, with a separate building used as an isolation hospital. The workhouse subsequently became a mental hospital. The buildings have more recently been converted and developed into new flats and housing.

[name] and its buildings have an institutional, austere and classical design and arrangement. Relevant to the appeal, their significance is their attractive and historic appearance, setting and integrity. Section 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the Act) requires that I have special regard to the desirability of preserving the listed building and its setting, or any features of special architectural or historic interest.

The Archaeology Assessment identifies that the appeal site was part of a walled garden associated with the isolation hospital building, now Nos. 3 and 4. This was set apart from the main workhouse building but linked to it. There is new residential development between the appeal site and the former workhouse building, with little if any intervisibility between them. The appellant disputes whether there continues to be a connection between the appeal site and [name].

However, the appeal site retains a green and largely undeveloped appearance, and is bounded by stone walling, reflecting its historic use. The former isolation hospital building is immediately adjacent to the site and is accessed through it. A lamppost outside the appeal site entrance has the same design as others within the overall complex. [address] runs close to the site edge and provides a further historic and physical pedestrian link to the former workhouse building. For these reasons, the appeal site remains an integral and legible part of the grounds of [name]. On this basis, it makes a positive contribution to the character and setting of the listed building and the surrounding area.

The proposal seeks to erect up to three dwellings. As a result, it could be developed for fewer than this number, as houses and/or flats. The layout and number of units could result in space being provided between and around the new building(s). Permitted Development rights for subsequent extensions and outbuildings to the dwelling(s) could be removed. Even so, residential development would inherently result in additional, appreciable built form on the site. As well as the residential buildings themselves, the proposal would necessitate new and prominent hard surfaced areas for parking, as well as the possible creation of retaining walls.

Details of the drainage arrangements are not before me, although these could be below ground and so might not appear out of place. Nevertheless, the proposal 1 Also referred to as 3 and [address]. would also remove parts of the existing frontage walls and railings. The resultant, more porous opening would diminish the strength of the established eastern boundary of the [name] site with [site address] .

For the above reasons, the proposal would undermine the green and attractive appearance of the site, which provides a degree of relief from the surrounding denser forms of development. It would result in the loss of one of few remaining open areas to the east of the former hospital and workhouse complex, and would undermine the legibility and integrity of the wider site.

Consequently, the proposal would detract from the attractive and historic appearance, setting and integrity of [name] and its buildings, and would harm the character and appearance of the area. On this basis, it would conflict with policies DP1 and DP7 of the Mendip District Local Plan (MDLP), adopted December 2024. These policies require that development contributes positively to local distinctiveness and identity, and results in attractive places that demonstrably have a form appropriate to the local context.

In the language of paragraph 215 of the National Planning Policy Framework (the Framework), the harm caused would be less than substantial. Nevertheless, in accordance with Framework paragraph 212, I give great weight to the harm to the setting and significance of the listed building as a designated heritage asset. MDLP policy DP3 requires that such harm would need to be justified by overriding public benefits. Framework paragraph 215 makes a similar requirement. I shall undertake this balancing exercise below.

The proposal would involve the creation of a new vehicular access at a junction between three limbs of [site address] , and across a widened pavement area. A traffic speed survey has been undertaken, which shows that vehicle movements hereabouts are relatively low, with speeds well below the posted 30mph limit. Nonetheless, the proposed visibility splay to the south would be shorter than the minimum length required by Manual for Streets (MfS), even when based on the actual recorded speeds.

There are examples locally of accesses which have visibility splays below the MfS standard, and the guidance advocates a flexible approach. No collisions have been recorded recently on [site address] . The position of the traffic counter beyond the proposed access may have resulted in higher speeds being recorded than would occur at the access point itself. The proposal may generate a relatively small number of movements, although it includes parking and access for Nos. 3 and 4. A Traffic Regulation Order could be used to ensure that parts of the visibility splay to the north would be unobstructed by parked vehicles.

Even so, the identified splays are taken from a point forward of the pavement, rather than being set back behind the proposed entrance. As such, the visibility of drivers leaving the site may well be partially blocked by adjacent walls, some of which would be retained. Furthermore, the angles of the splays would make it awkward for drivers leaving the site to achieve full visibility. This would be particularly the case when reversing out, for example from the proposed visitor spaces. I am also concerned that pedestrian access through the site to Nos. 3 and 4 would require its users to cross the wide frontage manoeuvring apron, with little or no protection, further risking their safety.

Given the factors identified above, the proposal would give rise to a very real potential for collision and conflict with other road users, including pedestrians both on the pavement and accessing Nos. 3 and 4. The Highway Authority has raised similar concerns. For the reasons given, the proposal would have a harmful effect on highway safety. Accordingly, it would conflict with MDLP policy DP9 which requires safe and satisfactory provision for access. This harm and conflict carries substantial negative weight.

On the basis that the proposal is for SBCH, it would be exempt from the biodiversity net gain objective, which requires a 10% increase in biodiversity value. The UU seeks to ensure that the dwellings would be developed as SBCH.

However, there are undisputed legal shortcomings with the UU, such as references to a single dwelling rather than up to three, and to an [name] that is not annexed. Furthermore, the UU permits the selling or letting of ‘the’ self-build dwelling to a member of the owner’s immediate family. As such, the initial occupier may not have had primary input into its final design and layout, such that it would not accord with the definition of SBCH. For these reasons, it is not certain that the UU would secure the proposal as SBCH.

Moreover, the UU undertakes that if a disqualifying event occurs, such as the dwelling(s) ceasing to be occupied as SBCH, then the owner would submit a [name] and Monitoring Plan. This would outline how habitats would be provided to ensure that the biodiversity net gain objective would be achieved.

That said, if not secured as SBCH, a minimum amount of information is required, as specified in the legislation2 and the Planning Practice Guidance3. A Preliminary Ecological Assessment (PEA) has been submitted. This identifies potential benefits, such as the inclusion of hedgerow around the site, the use of native species in planting schemes, and the provision of bat boxes.

Nevertheless, the PEA makes clear that a full biodiversity net gain assessment would be necessary. This has not been provided. Missing information includes the pre-development biodiversity value of the site, the full metric, and details of any degradation. Trees and vegetation have been felled at the site, which may well affect the ecological baseline. Consequently, it is not clear that the biodiversity net gain objective could be achieved without for example requiring off-site gains.

Despite the UU, the appellant has suggested that a planning condition could be used to require that the development would have SBCH status. However, a condition limiting occupation in this way would be difficult to enforce, thus failing the tests of the Framework. A planning condition requiring a 10% gain has also been suggested by the appellant. However, the minimum information is not before me, and I have already found that off-site gains may be required, which could not be secured by a planning condition.

For the reasons given above, insufficient information has been provided to show that the biodiversity net gain objective is capable of being met. Accordingly, the proposal would conflict with the relevant legislation. It would similarly not accord 2 Schedule 7A of the Town and Country Planning Act 1990 inserted by the Environment Act 2021. 3 Paragraph: 011 [name]: 74-[phone] with MDLP policy DP5, which requires the protection, enhancement and restoration of local ecology. I give this conflict substantial negative weight.

Nos. 5, 7 and 9 are tall properties that front onto the stepped footpath of [address]. They have windows which face towards the appeal site. Nos. 3 and 4 are semi-detached properties formed from the conversion of the former isolation hospital. No. 3 has a gable end facing onto the appeal site and No. 4 has a pedestrian gate leading from the path through the site. Both properties therefore have private garden and amenity areas adjacent to the proposal.

The two-dwelling indicative layout plan shows that a new dwelling (H1) would be positioned with a gable end close to the boundary with [address]. Despite the intervening footway and vegetation, and depending on the height of any building proposed here, this arrangement could have a dominating and overshadowing impact on the windows of these properties.

Based on the indicative plan, another new dwelling, H2, would be positioned opposite to the gable end of No. 3, and relatively close to it. On this basis, any windows on the rear elevation of H2 would face towards the private gardens and amenity spaces of Nos. 3 and 4, potentially undermining their privacy. As a result, based on the illustrative layout, the proposed dwellings H1 and H2 could adversely affect the light and outlook, or privacy, of nearby occupiers.

At this stage, the position and number of dwellings is not fixed, other than a cap of three. Development could be set into the sloping ground and have a low height, to limit its impact on neighbouring properties. It could be positioned in a different arrangement to that shown illustratively. The use of landscaping, and restricted, obscure-glazed windows for example could limit the adverse effects.

Even so, the access arrangements are fixed at this stage, limiting the potential options. Few details of the design of the proposed development, or of existing and proposed site levels or cross-sections, are before me. As such, it has not been demonstrated that a proposal could be developed which overcomes the concerns raised above, whilst also being consistent with other planning requirements, such as for good design.

For the reasons given above, the proposal could well harm the living conditions of occupiers of dwellings at numbers 5, 7 and [address], and numbers 3 and 4 Louvain. It would therefore conflict with MDLP policy DP7, which requires demonstrable protection of the amenity of users of neighbouring buildings. I give this harm and conflict significant negative weight.

There is no dispute that the Council cannot demonstrate a sufficient supply of deliverable housing sites. Even so, the policies in the Framework that protect assets of particular importance, in this case the designated heritage asset and its setting, provide a strong reason for refusing the proposal. It follows that the tilted balance of Framework paragraph 11(d) is not engaged.

The proposal is for SBCH development, and there is no dispute of the high demand for such accommodation in the area. However, for the reasons already given, I am concerned that this status would not be secured. Even so, small sites can make an important contribution to meeting general housing needs. The development would make a positive addition of up to three dwellings within a principal settlement. As such, I give this benefit positive but limited weight.

Future occupiers of the dwelling(s) may well make positive social and economic contributions to the local area. The proposal would have other economic benefits, for example to local businesses and the building industry. I am mindful of the support of the Framework for economic growth. The development would make more efficient use of land, on a site that is close to the services and facilities of the town. I give these matters additional, limited positive weight.

The proposal lies within an area where it may affect the [name] and Moors Ramsar Site. This is protected pursuant to the Conservation of Habitats Regulations 2017. [name] found no harm in respect of the main issues, as competent authority I would have carried out an Appropriate Assessment in respect of the potential effects on the Ramsar Site. However, as the balance of considerations is against the proposal, this matter need not be considered any further in this case.

Given the weight that I have attributed to the benefits of the proposal, individually and cumulatively they would not outweigh the harm caused to the setting of the designated heritage asset, to which I have given great weight. It follows that the public benefits would not provide sufficient justification for the proposal. Consequently, it would conflict with MDLP policy DP3, and the test of Framework paragraph 215 is not met. Similarly, it would not accord with the Act.

For the reasons given, I have found conflict with the Development Plan as a whole. The material considerations in this case, and the weight I give to them, do not indicate a decision other than in accordance with the Development Plan. This leads me to conclude that the appeal should be dismissed.