Appeal 3354429

The appeal is allowed and planning permission is granted for a single storey rear extension and a two storey front extension at [site address] in accordance with the terms of the application, [name]/1781/24, subject to the following conditions:

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: Location Plan, Existing Site Plan, Existing Block Plan, [name] & [name], [name], [name] & [name], Proposed Site Plan, Proposed Block Plan, [name] & [name], [name], [name] & [name], and [name] & [name] (depicting the roof plan).

The materials to be used in the construction of the external surfaces of the development shall match those used in the existing building.

An application for costs was made by [name] against Harrow Council. This is the subject of a separate decision.

The latest version of the National Planning Policy Framework was published in December 2024 (‘Framework’). It is therefore that version that I have considered, rather than the now superceded version which was in place at the time of the Council’s decision.

The main issues are the effect of the proposal on: • the character and appearance of the host property and the area; and • the living conditions at [address] (‘No 149’), with particular regard to outlook and overshadowing.

The host comprises a typical ‘metroland’ style, detached, hipped roofed building, which faces [address], with its side wall set well back from the junction with [address]. Compared to the buildings on this side of [address] to the west, and those on the opposite side of the junction to the east, the host’s front face is set back further from the highway. As a result, considered in isolation, the Council does not object to the proposed front extension, which would match the host in terms of its style, form and materials. For similar reasons, neither do I.

The scheme would also include a single storey rear extension. This would be around 7.8 metres deep, would extend across the whole of the host’s rear face and, according to the Council’s delegated application report (‘DAR’), it would be around 3 metres high.

The rear extension’s flat roof would be at odds with the host’s roof form, but would also serve to lessen its bulk. [name] did not observe any extensions of a similar form and scale nearby, in public vantage points from [address] it would be seen across an intervening parcel of land and partially against the backdrop of a taller end of terrace house beyond. Thus, it would not be very prominent in the streetscene, and it would be largely or entirely screened if conifers planted along the boundary with [address] continue to grow.

Nevertheless, the rear extension would be an overly elongated addition which, notwithstanding the proposed use of matching materials, would not entirely respect the host’s design. Having regard to cumulative impacts with the proposed front extension, the scheme would add significant bulk to the original building, such that its original proportions would be difficult to read. It would therefore cause modest harm to the character and appearance of the host property and the area.

As a result, there would be a limited conflict with Policy D3 of the London Plan (2021) (‘LP’); Policy DM1 of the Harrow Development Management Policies (2013) (‘HDMP’); and Policy CS 1 B of the [name] 2012. Amongst other things, and in general terms, these require a high standard of design which responds positively to local character and distinctiveness, and to the site’s context, having regard to matters such as appearance, shape, form, scale, bulk and massing; and require extensions to respect the host building.

There would also be a limited conflict with the Framework’s stance that development shall be of a good design, which is sympathetic to local character; and with the advice in the [name] Planning Document 2010 (‘SPD’) that extensions should harmonise with the original building, not dominate it and have a subordinate volume; and that rear extensions should be designed to respect its character and scale.

No 149 sits on a wide plot, with its side wall abutting the boundary with No 147. Given the staggered relationship between these two buildings, the proposed rear extension would project well beyond its rear face. However, it would be set in from the plot boundary, and its single storey flat roofed form would lessen its mass when viewed from the nearest rear windows in No 149’s single storey rear extension, and from its adjacent area of hardstanding.

Moreover, the outlook towards the appeal site from both those places is already constrained by a row of tall conifers. Thus, whether or not that landscaping would be retained, or more trees would be planted, the outlook from No 149 would not become significantly more enclosed by this scheme, and there would not be a significant overbearing impact on its occupiers.

The rear of No 149 faces south-south-east, such that for at least most of the afternoon the scheme would not have an overshadowing impact. Even in the morning, in the context of the existing landscaping, and the proposed rear extension’s low flat-roofed form, any additional overshadowing would be limited.

The scheme would not therefore harmfully impact the living conditions at No 149. On this issue it would not conflict with those parts of LP Policy D3 or HDMP Policy DM 1 that development shall achieve a high standard of amenity, having regard to matters such as the relationship between buildings, visual impact, and the adequacy of light and outlook. Neither would it conflict with the Framework’s requirement to provide a high standard of amenity.

The SPD does not set a clear maximum advised depth for single storey rear extensions, but having regard to the criteria in its paragraph 6.59, and the recommended maximum height of 3 metres for extensions abutting a property boundary in its paragraph 6.63, I am satisfied that this one’s impact on the amenity of neighbouring residents would be acceptable.

The appellant maintains that this property is occupied as a single dwelling. Whilst section 1.0 of the DAR refers to it as consisting of three self-contained flats, at section 6.3 it continues that the property has ‘reverted back to a single dwelling’. Having regard to the appeal statement, the statutory declaration1, a Lawful Development Certificate which stated that a proposal fell within the parameters of permitted development as set out under Schedule 2, Part 1, Class E of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended)2, I am satisfied that it is currently a single dwelling.

In favour of his scheme, the appellant refers to planning permission for a two storey front extension to this dwelling3 and a decision that prior approval was not required for a single storey rear extension4. He states that these are identical to the 1 Dated 17 October 2024 2 Ref: PL/1746/24 3 Ref: P/3694/22 4 Ref: P/4253/22/PRIOR extensions before me. In its DAR the Council states that the front extension in the scheme before me is ‘materially the same’ compared to that extant planning permission, and it does not dispute the appellant’s claim that the rear extension is the same as that prior approval scheme.

I have no cogent reason to doubt that those schemes could be lawfully implemented in a sequential manner as claimed, or that there is more than a theoretical prospect of that development occurring. Thus, whilst the Council objects to the combined impact of both these schemes, and references concerns regarding ‘overdevelopment of the site’ in previous appeal decisions, this is a legitimate fallback, deserving of significant weight in my decision.

Finally, I have noted concerns raised by a local resident regarding an outbuilding, which he states has been left in a dangerous state and that it could contain asbestos. However, having regard to the submitted plans, that forms no part of the scheme before me.

Summing up, I have found that the scheme would not harmfully impact the living conditions at No 149, but that it would have a modestly harmful impact on the character and appearance of the host property and the area. As a result, there would be a limited conflict with the development plan when considered as a whole.

However, the existence of a fallback with similar impacts is a material consideration, to which I attribute significant weight, and which overcomes that limited conflict. The appeal will therefore be allowed.

Turning to the matter of conditions, I have considered those suggested by the Council against the tests in the Framework. The time limit for commencement is necessary, as is, in the interests of certainty, a condition requiring that the development be carried out in accordance with the approved plans. Finally, in the interests of good design, I have imposed a condition requiring that the extensions be faced in matching materials.

For the above reasons, and having regard to all other matters raised, the appeal is allowed.