Appeal 3348831

The appeal is dismissed.

The main issues are the effect of the proposal on the character and appearance of the building and whether it would conserve or enhance the character or appearance of the Devisdale Conservation Area. In addition, whether it would preserve the setting of the listed building of Erlesdene.

In accordance with the duty imposed by section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 I am required to pay special attention to the desirability of preserving or enhancing the character or appearance of the conservation area. Moreover, paragraph 212 of the National Planning Policy Framework (the Framework) states that when considering the impact of new development on the significance of a designated heritage asset, great weight should be given to the asset’s conservation (and the more important the asset, the greater the weight should be). This is irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to its significance.

The conservation area is named after The Devisdale, a historic area of unenclosed flat land at the top of [address]. It includes the wooded north slope of the hill and the gentler west slope towards [name]. The planning of the area was closely controlled by the Earl of Stamford to create a social neighbourhood to nearby Dunham Park. Its significance and special interest include development in the second half of the 19th century, characterised by houses on a grand scale, set in large plots at a low density with magnificent gardens, sweeping drives and coach houses. There are many large, fine, individual residences in the area, in a variety of architectural styles. Some of the houses are the work of renowned architects.

The appeal building is a two storey detached dwelling located on a small cul-de-sac. It is part of a modern estate of houses at Green Courts of similar form and design, and spacious surroundings. Number [site address] was built as a later addition to the estate and has a large rear garden. The rear elevation of the dwelling may be seen across the garden from Green Walk, between the neighbouring building and tennis courts.

The proposed extension would replace the existing single storey part of the building development which currently appears as a pleasant subservient feature. The separation distance to the boundary with 32 Green Courts would be reduced to around 2.5 metres from approximately 7.5 metres by the proposed two storey side extension. Although the building sits within a large plot, the proposed extension would add undue scale, height and bulk at the flank of the building where space is more constrained. In this respect it would be contrary to the Devisdale Conservation Area Management Plan which indicates that side and/or rear extensions which would significantly reduce the intervening space between the existing building and plot boundary would be inappropriate development in the conservation area. Although other side extensions have been constructed in the wider development, and the Council would normally in other cases consider a separation distance of around one metre to be acceptable I consider that in the particular circumstances of the proposed development, and its location within a conservation area, the proposed development would fail to preserve or enhance the character or appearance of the conservation area.

In view of the size of the proposal, the harm to the conservation area as a whole and its significance would be less than substantial. Paragraph 215 of the Framework indicates that where a development proposal will lead to less than substantial harm to the significance of a designated heritage asset, this harm should be weighed against the public benefits of the proposal including, where appropriate, securing its optimum viable use. However, the benefits from the proposed two storey side extension would primarily constitute private benefits, rather than public benefits, and would not outweigh the harm that I have identified to the character and appearance of the conservation area as a designated heritage asset.

The proposed development would fail to comply with policies JP-P1 and JP-P2 of the Places for Everyone Plan which seek to ensure sustainable development and the conservation of heritage assets. There would also be conflict with the heritage objectives in the Framework.

Turning to the effect on the setting of the listed building, Section 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1999 requires that in considering whether to grant planning permission for development which affects a listed building or its setting, special regard shall be had to the desirability of preserving the building or its setting or any special architectural or historic interest which it possesses. [name] 2 the Framework defines the setting of a heritage asset as the surroundings in which it is experienced.

The appeal building is located near to the grade II listed building of Erlesdene, a Victorian/Gothic building built in 1873. However, I consider that there would be no adverse impact on the setting of the building from the proposal. That is because there is a significant separation distance between the site of the proposed extension and Erlesdene. Moreover, the roadside trees at Green Walk provide a high level of screening for the listed building.

The appeal property has an extant planning consent for an extension at the opposite end of the building which the Council advises as expiring on 9 February 2027. The extant consent is a material consideration. If the appeal proposal was allowed the construction of the already permitted extension and the proposed extension together would result in a linear building with varying design elements in its rear elevation when viewed from Green Walk.

There are no other considerations sufficient to outweigh my finding that the proposed two storey side extension would have a harmful effect on the character and appearance of the building and would fail to conserve or enhance the character and appearance of the Devisdale Conservation Area. The proposal would conflict with the development plan as a whole.

For the reasons given above the appeal should be dismissed.