Appeal 3280809

The appeal is allowed and planning permission is granted for a first floor side extension and new roof dormer at [site address] , in accordance with the terms of the application, [name]/1650/21, dated 15 April 2021, subject to the following conditions:

The development hereby permitted shall be begun not later than 3 years beginning with the date of this permission.

The development shall be carried out in accordance with the approved plans: Drawing 2120/01 dated April 2021.

The materials used in the construction of the external surfaces of the works hereby permitted shall match those of the existing dwelling.

The main issue is whether the proposal would preserve or enhance the character or appearance of the conservation area.

The property lies within the Mount Park Conservation Area. This is characterised by the landscape setting of the quiet narrow roads of this gated estate that serve the often large detached and semi-detached Victorian and Edwardian houses. As many of the properties are set in mature spacious grounds, this ensures that the trees and vegetation are as important to the overall character as the buildings set within this landscaping. The appeal property is set away from the road network off a long shared private drive. It sits comfortably within its mature grounds with the built form being visible only in distant glimpses from public vantage points. www.planningportal.gov.uk/planninginspectorate Appeal Decision: APP/M5450/D/21/3280809

The proposal would extend the property by increasing the height of the existing single storey extension which has a flat roof. The front elevations currently stagger back from the main frontage and as a result the part of the building that would accommodate the extension, being furthest from the entrance gates, is already of limited prominence. The extension would follow the form, detail and materials of the house and would replace the flat roof of the side addition. This element would have very limited wider impact but would in any event, be of a good standard of design. The subordinate roof form and set back would generally accord with the requirements of the Supplementary Planning Document: [name] (2010). The detailing, form and lack of prominence would ensure that the extension would preserve the existing character and appearance of the conservation area.

The proposal would also include a rear dormer. This would match an existing dormer located within the same roof slope. Although the dormer would not be positioned to reflect the alignment of windows below it, this is already the case with regard to the existing dormer. Fleeting public views of this roof slope are possible between properties and vegetation from the south but generally only limited private views are available. Views of the full composition of the rear elevation, including the lower windows and the roof slope, are not generally possible.

The Mount Park Conservation Area Management Plan sets out that dormer windows should be of traditional design and not dominate the roof slope. It encourages shapes that are in keeping with the original profile but accepts that flat roofed dormers may be necessary in some cases. Given the character of the existing windows to the first floor and the details of the existing dormer that is to be retained, this modest matching flat roofed dormer would not be out of keeping in the position shown. Given that it would be to the rear and would match the existing, it would not result in harm to the appearance of the dwelling. As it would be of a satisfactory design, size and position; and of very limited wider prominence, it would preserve the character and appearance of the conservation area. It would not conflict with the Management Plan and the dimensions and position of the dormer fall well within the measurements set out in the [name].

Consultees have raised a number of concerns with regard to the scale and design of the proposal. It is evident that the house has already been extended on a number of occasions but it still sits centrally within the large plot and retains significant distances to the boundaries and properties beyond. It would not be perceived as closing a visible gap between neighbouring houses and the stepped approach and the removal of the flat roof of the existing structure, would provide some design benefits. Although it is suggested that the property fits in with the Arts and Crafts styles of the conservation area given its prominent chimney, gable and clay tile hanging; and that the Arts and Crafts style stylistically sought to express a rustic charm, this proposal would not alter these characteristics and importantly, it would not result in any loss of garden area or reduce the landscape setting.

Reference has been made to a similar proposal at this property which was dismissed at appeal in 2012. The detailed plans and the decision letter have not been provided for comparison. It would appear however, that significant alterations to the property have taken place in the intervening period. As this 2 Appeal Decision: APP/M5450/D/21/3280809 proposal would improve upon the existing side extension, I am not satisfied that the previous findings remain directly relevant.

Overall, the design has been carefully considered in order to improve upon the existing extensions whilst seeking to minimise the impact on the important design characteristics of the property. The materials would be consistent with the existing dwelling and the scale of development would continue to be accommodated comfortably within the existing landscape setting. Although the Council suggest that any decision should be conditioned to remove the proposed dormer, this is not necessary given that it would sit unobtrusively within the rear roofscape and match the existing. The proposal would not represent poor design and would not result in harm to the character or appearance of the area. The wider impact overall would be extremely limited and I am satisfied that it would preserve the character and appearance of the conservation area.

In conclusion, I find no conflict with the heritage and design policies of The London Plan 2021 (D3 and HC1); the Harrow Development Plan 2013 (DM1 and DM7); the [name]; or the guidance within The Harrow on the Hill Conservation Areas Supplementary Planning Document 2008, which the Mount Park Conservation Area Management Plan is a part. As the proposals would not result in harm to the conservation area and would preserve its character and appearance, no conflict with the National Planning Policy Framework would result. I therefore allow the appeal.

I have imposed conditions that refer to the timetable for commencement and make reference to the plans, for the avoidance of doubt. A condition to require that the materials match those of the dwelling is also necessary to ensure that the development would have a satisfactory appearance.