Appeal 3316002

The appeal is allowed and planning permission is granted for erection of one and two storey rear extensions demolition of existing extension at [site address] , Harrow, [postcode] , in accordance with the terms of the application [name]/3116/22, dated 29 August 2022, and the plans submitted with it, subject to the schedule of conditions on pages 3 and 4.

I consider that the main issues in this case are its effect on the character and appearance of the conservation area and on the living conditions of residents.

[site address] is a two storey detached house, one of four constructed in a similar Arts and Crafts style with distinctive features including gabled two storey bay windows to the front and hipped roofs. It lies within the [address] Conservation Area and in the setting of a Scheduled Ancient Monument.

There is a statutory duty under Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 to pay special attention to the desirability of preserving or enhancing the character or appearance of conservation areas. The National Planning Policy Framework (2021) (the Framework) states that in the consideration of development proposals great weight should be given to the conservation of heritage assets in accordance with the significance of the asset and any harm should require clear and convincing justification.

I consider that the relevant policies in this case include D3.D(1) and (11) and HC1.C of the London Plan (2012). These require new development to respond to local distinctiveness having regard to matters such as building types and forms and the architectural features which contribute to local character and heritage assets, and to conserve the significance of heritage assets and manage the cumulative impacts of incremental change.

[name] and D of policy CS1 of the [name] (2012) (the [name]) require development to respond positively to the historic context and state that proposals which would harm the significance of heritage assets will be resisted.

Policies DM1.A, DM1.C and DM1.D of the Harrow Development Management Policies Local Plan (2013) (the DMP) require a high standard of design and also relate to the protection of the privacy and amenity of neighbours.

Also relevant is the Council’s Supplementary Planning Document Residential [name] (2010) (the SPD) which among other things gives detailed guidance on maintaining the privacy of neighbours and the impact of the size and siting of extensions on the outlook from neighbouring properties and the use of the 45 degree code. It also states that an extension should not dominate the original building and should be of an appropriate scale and in proportion with it. Proposals relating to a conservation area should be sensitive to both the building and the surrounding area.

[address] Conservation Area Appraisal and [name] (2009) (the CAA) identifies the special interest of the area as being its well designed and mostly unaltered residential architecture and spacious garden settings. It also refers to the pressures on the character and appearance of the area arising from all forms of new development, including rear extensions, which might fail to respect the character and size of the original properties. Extensions have been allowed at the rear and are encouraged in preference to side extensions in order to avoid a terracing effect.

The CAA also identifies No. [address] of four examples of Metroland development, which form a unified group and stand out for their quality of architecture and setting. Extensions such as that at the side of No. 103 which notably alter this unity should be avoided.

The proposed extensions would be substantial in size and bulk and would alter the form and architectural character of the rear part of the house. This has already been altered to some extent by the existing single storey extension. The identity of the projecting two storey outrigger with its hipped roof would be somewhat compromised by the first floor extension across the full width of the house and the crown roof. However, the features identified in the CAA as contributing to the significance of the conservation area relate mainly to the unity of architectural features apparent along the street frontage and the spacious, landscaped character of the area. I consider that in this context, the proposal, although not, in my opinion, having a positive impact on the character of the building itself, would not harm the character and appearance of the conservation area, since it would not be visible in any public viewpoints. The plot is large and the spacious garden setting would remain.

I conclude that the proposal would not harm the character and appearance of the conservation area and that in this respect it is consistent with policies D3 and HC1 of the London Plan, CS1 of the [name] and DM1 of the DMP, the advice in the SPD and the aims of the CAA.

I consider that the proposal would not have a significant effect on the amenity of the neighbouring occupiers of [address]. Although the proposed single storey extension would project further into the garden than the existing, the latter would be demolished and the replacement would be lower in height with a flat roof instead of the existing partially pitched roof. The existing vegetation along the common boundary provides screening and already shades the existing patio at No. 95.

The proposal would not have an adverse effect on the amenity of the occupiers of No. 99 since the single storey extension would not extend beyond the existing single storey rear extension at the latter and the first floor extension would not project beyond the first floor outrigger. There is a substantial evergreen hedge and fence along the common boundary which provides additional screening.

I conclude that the proposal would not harm the living conditions of neighbouring residents and that, in this respect it is consistent with policies DM1.C and DM1.D of the DMP and the advice in the SPD.

For the reasons given above, the appeal is allowed.

I have considered the conditions put forward by the Council, having regard to the tests set out in the Framework. A condition detailing the plans is necessary to ensure the development is carried out in accordance with the approved plans and for the avoidance of doubt. A condition relating to the materials is necessary in order to safeguard the appearance of the locality and the [address] Conservation Area. The conditions restricting the use of the flat roof and the installation of additional openings are reasonable and necessary to safeguard the residential amenities of neighbouring residents. The condition relating to the approved [name] report is necessary to ensure the development will not cause harm to flora or fauna, and in particular protected species which may be on site, and to ensure the development does not result in a net harm in terms of biodiversity.

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: P22-73.1, P22-73.2, P22-73.3 and P22-72.4.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those of the existing building. All new brickwork, including the brick bond, roof tiles, external works and finishes shall match the existing adjacent work with regard to the methods used and material, colour, size, texture and profile.

The roof area of the extension hereby permitted shall not be used as a balcony, roof garden or similar amenity area without the grant of further specific permission from the local planning authority.

Notwithstanding the provisions of the Town and Country Planning (General Permitted Development) (England) Order 2015 (or any order revoking and re-enacting that order with or without modification), no windows or doors, other than those shown on the approved plans shall be installed in the flank elevations of the development hereby permitted without the prior permission in writing of the local planning authority.

The proposed development shall be implemented in accordance with the approved document [name] report (ref: 92289 [name] dated 7th November 2022), unless otherwise agreed in writing with the Local Planning Authority.