Appeal 3320385

The appeal is allowed and planning permission is granted for erection of part single storey side and rear extension, raising roof and loft conversion with rear dormer and side dormer, new gable ended roof on existing two storey front element, conversion of garage into habitable room, erection of front porch at [site address] in accordance with the terms of the application, Ref: P/4142/22 dated 5 December 2022, subject to the following

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

The materials to be used in the construction of the external surfaces of the development hereby permitted shall be as shown on the approved plans.

The development hereby permitted shall be carried out in accordance with the following approved plans: PA/27/E.01; Existing / [name] 02; Existing / [name] 03; PA/27/P.04; PA/27/P.05; PA/27/P.06.

Prior to the first occupation of the development hereby permitted, the proposed first floor window in the side elevation of the development hereby permitted (within proposed Bedroom 3) and the proposed window of the side dormer at roof level shall both be glazed with obscure glass and fixed shut to a height of 1.7 metres above the finished floor level of the room in which the window is installed and thereafter so retained.

The main issue in this appeal is the effect of the proposal on the character and appearance of the local area, including on the setting of the adjacent Canons Park Conservation Area and [name] listed Registered Park and Garden.

The appeal property is a large detached house on the south side of [address] and within a predominantly residential area. The immediate neighbouring property to the appeal property at No 29 is from a later date, but the surrounding houses are predominantly detached and whilst originally dating from a similar mid 20th century period, many have been altered and extended and include a variety of designs with a wide palette of materials. Contrary to the views of the Council, I observed on my site visit that many of the houses substantially fill the width of their plots leaving very nominal, if any, gaps to the side boundaries, including at first floor level. The uniformity of the street scene is generally maintained through the building line, eaves and roof ridge lines. The dwellings on the south side of [address] immediately adjoin the northern boundary of the Canons Park Conservation Area. Canons Park is also a [name] listed Registered Park and Garden.

The proposal would involve a number of extensions and alterations to the property including, amongst other proposals, a part single storey side and rear extension, raising the roof with a loft conversion including a rear dormer and side dormer, together with a new gable ended roof on existing two storey front element.

There is an existing single storey flat roofed garage built up to the boundary with No 29. This would be extended to include a first floor level over, again built up to the boundary but set back from the front elevation at first floor level with a hipped roof. The adjoining property at No 29 is set in from its side boundary with the appeal property and as a result a gap would remain between the two properties. Taking into account the very different design of the properties, the remaining gap between the two as well as the proposed set back of the first floor under a hipped roof, I am satisfied that there would remain a gap between the two properties and that there would be no terracing effect. The gap would be modest but would not be out of character with the pattern of development found along the street, in terms of very modest building gaps.

The roof would be extended and altered with two proposed dormers, one on the rear roof slope and the other on the side roof slope. The rear dormer would be centrally sited on the rear roof slope, set down from the ridge and set in from the side roof slopes. It would accord with the guidance at paragraph 6.68 of the [name] (SPD) that Generally, dormers should be subordinate features in the roof, should not overlap or wrap around roof hips and should never rise above the ridge. The retention of a clearly visible section of roof around the sides of a dormer window, including the upper corners, has the effect of visually containing them within the profile of the roof’.

In terms of the side dormer, this would be of modest proportions in relation to the side roof slope and side dormers are found on a number of the surrounding properties. Taking into account the type of roof, the scale of the proposals and the character and appearance of the house and those adjacent, as set out under Paragraph 6.67 of the SPD, I consider that the side dormer would sit comfortably in relation to the house as proposed to be extended and the surrounding properties.

Whilst the proposal would materially increase the size of the property, including at roof level, I consider that the extensions and alterations would not be overly large in relation to the plot or adjoining properties and the dwelling as proposed to be extended would be readily assimilated into the street scene.

The appeal site adjoins the designated heritage asset of the Canons Park Conservation Area. Section 72 (1) of The Planning (Listed Buildings and Conservation Areas) Act 1990 sets out in respect of development within Conservation Areas, special attention shall be paid to the desirability of preserving or enhancing the character or appearance of that area. Paragraph 200 of the National Planning Policy Framework (Framework) also refers to the harm to the significance of a designated heritage asset from, amongst other matters, development within its setting.

The significance of the Conservation Area is focussed on the original Canons Park Estate including the [name] listed mansion and landscaped park and gardens extending out to include the surrounding planned residential estate, all in a spacious sylvan setting. The north west part of the Conservation Area adjoining the rear of the properties in [address] comprises a range of buildings which form part of the [name]. The part of the Conservation Area backing onto the appeal property and neighbouring properties is fully screened with a wide belt of dense and mature planting.

As existing, and with the wide tree belt, there is no visual interrelationship between the appeal site and adjoining buildings and the buildings within the Conservation Area. In the unlikely event that all the vegetation was cleared, the appeal property as proposed to be extended would be seen as one of a number of large residential properties of differing designs to the north of the Conservation Area. I do not consider that the proposed changes to the appeal property would materially affect the way in which the Conservation Area would be experienced compared with the current situation, given the varied individual designs of the houses on this side of [address]. I am not persuaded that the proposed changes to the appeal property would materially affect either the views into or out of the Conservation Area and would not therefore materially harm the significance of or the setting of the Conservation Area. The setting of the Conservation Area would be preserved.

I therefore find that the proposal would respect the character and appearance of the local area and would preserve the setting of the Canons Park Conservation Area and the Registered Park and Garden. There would be no conflict with Policies D3.D (1) and (11) and HC1 of the London Plan, Policies CS1.B and CS1.D of the [name], Policies DM1 and DM7 of the Harrow Development Management Policies Local Plan, the Council’s SPD and the Canons Park Conservation Area Appraisal and [name] as well as the National Planning Policy Framework, and in particular Sections 12 and 18 all of which seek a good quality of design which respects the local context and the significance of heritage assets.

In terms of conditions, the materials should be as specified on the approved plans to protect the character and appearance of the local area, and the approved plans should be listed for the avoidance of doubt and in the interests of good planning. I shall also add a condition to require the new side facing window at first floor (shown to be within Bedroom 3) as well as the window in the side dormer to be obscure glazed and fixed shut to a height of 1.7 metres above the finished floor level of the room in which they are situated, to protect the amenities of surrounding neighbours.

For the reasons given above and having regard to all other matters raised, I conclude that this appeal should be allowed.