Appeal 3352845

The appeal is dismissed.

There are two main issues. Firstly, the effect of the proposed extensions and alterations on the character and appearance of the host dwelling and the surrounding area; and secondly, the effect of the proposed extensions and alterations on bats, which are a protected species.

The appeal dwelling is a large, L-shaped detached house with a detached double garage set on a spacious plot in an isolated position on [site address] . It lies within open countryside with its side elevation close to the lane. The dwelling and garage were constructed during the 1990s and are of cohesive but undistinguished design. They are of brick and render construction under hipped, tiled roofs.

The proposed development comprises large two storey front extensions of different depths and widths under gabled roofs, and a single storey link to connect these with the garage. The roof of the original house would be replaced with a gabled roof which would match the roofs of the front extensions. The extensions would infill the significant gap between the house and garage. Overall, they would result in a dwelling more than twice the size of the existing.

The first section of front extension would sit either side of the L-shaped front projection. It would be shallow but wider than the original dwelling on both sides and would have a gabled roof that would have an eaves height that sat just below the eaves of the original dwelling. An additional two storey extension, about half of the width of the first section and about twice its depth, would be constructed between it and the garage. This would be off-set from both the original dwelling and the shallow front extension. It would have a lower ridge height than the shallow middle section. The single storey flat roofed extension would infill the remaining small gap between the house and garage.

The extensions as a whole would result in a dwelling that lacked a sense of cohesiveness. The different widths, depths and heights of the three gabled sections would appear disjointed from each other and from the hipped roofed garage. They would completely subsume the original main façade which, although not of notable architectural quality, has a sense of harmony and proportion. In contrast, the proposed front elevation, including the fenestration, would lack design merit, appearing discordant and fragmented.

Both the front and south-west elevations would be clearly visible from [site address] through the entrance to the site and, to a lesser extent, over the roadside hedge. In these views they would block the open aspect between the existing house and the garage, which together with the existing dwelling would form a significant length of built development close to the lane. Both this loss of openness and the lack of architectural merit would noticeably detract from the rural character and appearance of the area.

With respect to the rear elevation, an existing conservatory would be removed. I agree with the Council that this would be acceptable. I also consider that, whilst the proposed fenestration would be different and this, coupled with the new gabled roof, would materially alter the appearance of the rear façade, the changes overall would have pleasing symmetry and proportion and that no material harm would arise.

The appellant suggests that the proposed extensions would make efficient use of the site and improve the accommodation for occupiers and thus function well. It is also suggested that the design would add architectural interest and character but would not compete with other dwellings owing to its isolated location. Finally, a comparison is drawn between the appeal proposals and the closest neighbour, Longacres, which is a large property with gable ends and a single storey hipped front projection. However, none of these matters would outweigh the harm identified to the character and appearance of the host dwelling and the surrounding area. With respect to Longacres, whilst there are superficial similarities, I do not find that the proposed extensions are readily comparable with the careful and cohesive design of Longacres.

It is concluded on the first main issue that the proposed extensions and alterations would owing to their scale, design and location, materially detract from the character and appearance of the host dwelling and the surrounding area. In consequence, they would conflict with Policies CP9, DM35, DM36 and DM44 of the Wycombe District Local Plan (LP), 2019, and with the Householder Planning and Design Guidance Supplementary Planning Document, 2020. Taken together and amongst other things these expect extensions to dwellings in the countryside to respect the character and appearance of the existing property and the surrounding area and be subservient to the host dwelling, such that they create positive and attractive buildings and spaces with a high quality of design in respect of scale, form and layout so that they contribute positively to the distinctive character of the area.

Turning to bats, all bat species are designated and protected as [name] (EPS). EPS are protected under the Conservation of Habitats and Species Regulations 2017. [address] is a known bat roost as confirmed by the [name] (PEA), including three dusk emergence surveys, undertaken between April and September 2024. The survey identified bat droppings in the roof void of the existing dwelling and a number of potential entry/exit points were seen, although no bats were recorded exiting the site during the emergence surveys. The proposed alterations to the dwelling include the replacement of the entire roof which would thus destroy the identified bat roost.

Circular 06/2005 states that it is essential that the presence or otherwise of protected species, including bats, and the extent to which they may be affected is established before planning permission is granted. In particular, before granting planning permission, a decision maker must be confident that the impacts of the proposed development on EPS have been addressed and that if a protected species derogation licence is required, the licencing tests can be met and a licence is likely to be issued by Natural England.

The proposed development would destroy an identified bat roost and although recent emergence survey data is negative, I have no evidence that the revised PEA report has been independently reviewed. Moreover, it states that a licence would be required. I cannot therefore be certain that the submitted evidence is sufficient to assess the potential harm to bats, whether that harm could be adequately mitigated and whether the licensing tests can all be met. [name] 06/2005 requires impacts and mitigation to have been addressed before planning permission is granted, the matter cannot be dealt with via planning conditions. I must therefore adopt a precautionary approach.

It is concluded on the second main issue that it has not been demonstrated that the effect on bats would be acceptable and capable of suitable mitigation. In consequence, the proposed extensions would be contrary to Policies DM13 and DM14 of the Delivery and Site Allocations Plan, 2013, LP Policy DM34, Circular 06/2005 and the National Planning Policy Framework. Taken together, these resist permitting new development that would fail to protect and enhance biodiversity and, in particular, affect species of international or national importance. Development will only be permitted where it is demonstrated that the impact on EPS can be mitigated and that the benefits of the development outweigh the harm to biodiversity or conservation interests.

For the reasons set out above and having regard to all other matters raised, I conclude that the appeal should be dismissed.