Appeal 3342870

The appeal is allowed, and planning permission is granted for single storey rear extension. Part two storey rear extension with alterations to existing hipped roof to mansard roof. Alterations to existing dormer roof to rear elevation. Alterations to single storey roof. Alterations to openings. Internal alterations, new rooflights at [site address] , Hertfordshire, [postcode] Ref: 5/23/1408 and the plans submitted with it subject to the following conditions:

The development hereby permitted shall be commenced before the expiration of three years from the date of this permission;

The development hereby permitted shall be carried out in accordance with the following approved plans: 2178_PL01_SITE LOCATION and 2178_PL01_ (PROPOSED PLANS AND ELEVATIONS);

The external materials used within the development hereby permitted shall match those of the existing dwelling or be as specified on the application form. Materials will be maintained for the lifetime of the development and any changes shall be submitted to, and approved in writing by, the Local Planning Authority.

The main issues are the impact of the proposal upon i) the existing dwelling and the character and appearance of the street scene and locality and ii) the residential amenity of neighbouring occupiers with regard to overbearing impact.

There are several elements to the appeal proposal, as outlined in the development description at the start of this decision letter, and the Council confirms, within their delegated report, that the proposed roof lights for the front of the dwelling are considered an acceptable addition. No issues appear to be raised in relation to the alterations to openings either. Taking into account the evidence before me, I have no reason to conclude differently on these elements so, in that regard, this appeal will focus upon the remaining elements of the proposal within the context of the two main issues outlined.

The appeal site is a two-storey, semi-detached, dwelling house constructed in brick with a tiled roof and white UPVC fenestration. It is located within a residential area, and, at the time of my site visit, I found that immediately surrounding the appeal site there is a mix of types of dwellings including a mix of architectural styles. The proposal seeks to increase the width of the two-storey rear extension as well as alter the roof to create a crown roof form.

I note that the neighbouring dwelling, at [address], benefits from a single storey attached garage at ground level but despite this, I note that the garage in question has a roof pitch which is consistent with the host dwelling which creates a more notable ridge height than typical single storey garages. As a result of this, I find that the proposed crown roof would likely have very limited visibility from the street due to the close proximity of the neighbouring dwelling and the presence of the garage. At the time of my site visit I also went around the corner of [address] and found views to be limited elsewhere within the street scene given the distance in question but also that [address] is set back within the corner plot, which brings built form further back than the proposal that is before me, overall limiting views.

I find that the proposal would have extremely limited visibility within the street scene with only glimpsed views potentially available of the appeal proposal and even then, such views I find would generally be if only people were specifically looking to view the site in question. The roof form would be read as having hipped ends with a flat roof element overall not being discernible. The front elevation of the host dwelling would remain largely the same, with the exception of the introduction of roof lights, and whilst I acknowledge the character and appearance are separate matters, the proposal would largely retain the eaves line of the existing two storey rear extension, would not be higher than the ridge line of the original dwelling and whilst it would evidently add additional bulk, I do not find that this would fail to preserve the character and appearance of the host dwelling in this case.

The Council acknowledge that there are a number of examples of two storey rear extensions within the immediate vicinity, however, these are all stated to feature pitched roofs with either gabled or hipped ends. Despite this, the appellant has evidenced, within their statement, that crown roofs are not uncharacteristic within [address] with the examples provided being in much more visually prominent locations than the appeal proposal which is before me. The proposal also seeks to enlarge the existing rear dormer as well as installing a small dormer on the window on the rear facing Mansard roof slope. Whilst this would introduce a large quantum of flat roof, I do not find that this would change the character of the building to the detriment of the area taking into account the clear examples that the appellant has provided of flat/crown roofs on [address] which are characteristic of the area and in much more visible and prominent locations. Whilst the proposals would, evidently, result in change, I do not find that the cumulative impact of the proposed roof alterations would be excessive in relation to the exiting dwelling nor that they would result in an incongruous addition that would be detrimental to the character and appearance of the street scene and locality.

The proposal would be consistent with St Albans Local Plan Review 1994 (LP) Policy 69 which requires development to have an adequately high standard of design taking into account context and materials and LP Policy 72 which requires extensions to relate to the domestic scale, character and appearance of the street as well as being compatible with the original building. The proposal would also be consistent with the Harpenden Neighbourhood Plan 2018 Policy ESD1 which requires all developments to be visually attractive, designed to a high quality and maintain or enhance the character of the area. The proposal would also be consistent with paragraph 135 of the National Planning Policy Framework 2023 which seeks to ensure that developments are visually attractive as a result of good architecture and are sympathetic to local character and history including the surrounding built environment and preventing or discouraging appropriate innovation or change.

The second part of the refusal reason is specific to [address] (no. 4) with the impact of the proposal having been assessed as appropriate in relation to [address]. I have no reason before me to conclude differently in relation to no. 44. The Council’s delegated report, and the refusal reason, confirms that the refusal reasoning is based upon the depth and height of the proposed single storey rear extension leading to an unacceptable overbearing impact upon the occupiers of no. 40.

At the time of my site visit I noted that no. 40 benefits from a rear facing opening within close proximity to the boundary which the Council suggest, from planning history, is the only opening to a family room. The proposed single storey extension would be positioned along the boundary with no. 40 which does not currently benefit from any rear extensions on the shared boundary. The appeal site already benefits from a single storey rear extension with a mono pitched roof the depth in the region of 3.1 metres which, at its highest point, is 3.4 metres. The proposed rear extension would measure in the region of 3.75 metres and would be in the region of 2.38 metres in height along the whole extent as a result of exchanging the existing mono pitched roof with a flat roof.

It is, therefore, a material consideration that a single storey extension already exists adjacent no. 40 and is, at its highest point (closest to the window which serves the family room noted by the Council) in the region of 1.3 metres higher than the appeal proposal. The introduction of a deeper extension, at an overall lower height, I do not find to cause any greater overbearing impact on the ground floor window of the neighbouring property than the existing extension. The proposal would, I find, essentially reduce height closest to and immediately adjacent to the family room window and amenity area at no. 40.

LP Policy 72, stated within the refusal reason, outlines that single storey extensions shall not normally extend more than 3 metres rearward along a party boundary. Whilst the proposal would be contrary to the 3 metres stated, the wording within LP Policy 72 does infer some element of flexibility, to be assessed on each case, with the inclusion of the word normally. A lack of objection is a neutral consideration, however, overall whilst I acknowledge the depth of the proposed single storey extension, I find that the height is overall limited, as a result of the flat roof, and would not result in any greater impact to residential amenity in terms of overbearingness than the existing single storey extension.

The proposal would be consistent with LP Policy 72 which, whilst acknowledged to limit extensions to 3 metres rearward along a party boundary, this is still consistent with the overarching objectives of that policy which seeks to ensure that the amenity of adjoining property shall not be unacceptably harmed. The proposal would also be consistent with paragraph 135 of the Framework which seeks to ensure developments create places with a high standard of amenity for existing and future uses.

I note that Harpenden Town Council responded to this application stating that they recommend refusal due to the reasons for refusal of the previous application (5/2022/2698) having not been sufficiently addressed. It is outlined that the current proposal reduces the height of the proposed single storey rear extension by in the region of 0.2 metres and the base width of the Mansard roof was also reduced by approximately 0.7 metres. I do not have any further details of the previous application before me; however, this is of limited relevance and I have assessed the case, which is before me on its own merits, against the Local Plan, based upon the evidence before me and what I have seen at the time of my site visit.

The Council has suggested four conditions, in the event this appeal is allowed, which I have considered and applied as necessary. A time condition is attached to comply with Section 51 of the Planning and Compulsory Purchase Act 2004. A condition requiring the development to be in accordance with the approved plans is required to control and define the development which is granted consent. A materials condition is required to ensure an appropriate finish in accordance with the details submitted.

A condition relating to obscure glazing in the first-floor side elevation window facing towards [address] (which would serve a staircase) is suggested by the Council to protect the privacy of neighbouring occupants. I have considered this condition, however the location of the window in question is within the original side elevation and faces towards the side of no. 44 where there are no windows other than in the rear of the roof of the garage building. Taking into account the orientation of the window and its positioning I do not find that obscure glazing or controlled opening is required to make the proposal acceptable though I acknowledge it is shown on the proposed plans as frosted.

For the reasons outlined above the appeal should be allowed subject to