Appeal 3376106

The appeal is allowed and planning permission is granted for single and two storey side to rear extensions; conversion of garage to habitable room; rear patio with steps; external alterations, at [site address] , Harrow [postcode] , in accordance with the terms of the application, [name]/1665/25, subject to the following conditions:

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

The development hereby permitted shall be carried out in accordance with the following approved plans: [name] – 01 [name] – 06 [name] – 08 [name] – 09

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

The description of development in the banner heading above is taken from the planning application form. The appeal form more concisely describes the development as “Single and two storey side to rear extensions; conversion of garage to habitable room; rear patio with steps; external alterations”. This is consistent with the description used on the Council’s formal decision notice and accurately describes the development. I have therefore adopted this shorter description for the purposes of determining the appeal.

The formal decision notice refers to conflict with “Policy DMC” of the Harrow Council Development Management Policies, July 2013 (the DMP). The Council has since confirmed that this was a typographical error, and that the correct reference is DMP Policy DM1, specifically [name], which deals with amenity considerations. I have determined the appeal on this basis.

The main issue is the effect of the proposed development on the living conditions of the occupiers of the neighbouring property at No [address], having specific regard to sunlight, outlook and sense of enclosure.

Taken together, Policy D3.D of the London Plan, March 2021 (the LP) and Policy DM1 of the DMP seek to ensure developments deliver appropriate outlook, privacy and amenity for existing and future occupiers. The Supplementary Planning Document Residential [name] (the SPD) provides detailed guidance for the design of house extensions to support the development plan policies.

The SPD prescribes a “45 [name]”, and the Council contends that the first‐floor rear element would breach its horizontal and vertical tests and harm a “protected window” at No [address] (No 24). This is the ground floor window on the recessed part of No 24’s rear elevation, adjacent to the shared boundary with the appeal site.

The evidence before me does not allow for a confident determination of which of the various openings constitutes the “primary” or “protected” window for the purposes of SPD paragraph 6.26. The appellant’s description of the external arrangement aligns with my own observations, and their account of the internal layout would, if correct, indicate that the main outlook is taken from the rear-facing windows within No 24’s ground-floor rear extension. However, no party has provided sufficiently detailed internal evidence to confirm this. In these circumstances, and applying SPD paragraph 6.29, which cautions against mechanical use of the 45 degree code, I cannot be satisfied that material harm has been demonstrated, and there is no clear conflict with LP Policy D3 or DMP Policy DM1.

I have also had regard to the neighbour objection, which expresses understandable concern regarding loss of natural light to a kitchen. Based on the evidence, this objection is likely, though not confirmed, to have come from No 24. [name] give this some weight, it does not provide the level of detail necessary to identify the primary window or to resolve the underlying uncertainty noted above.

In any event, the window identified by the Council sits within a recessed area formed by the adjoining single‐storey extensions at Nos 24 and 26. From my own observations, it already appears constrained by the existing built form to the extent that it fails both the horizontal and vertical elements of the 45 degree code. Whilst the proposed extension would add mass above the single‐storey structure, and its position to the south of the window may lead to some further reduction in sunlight, the existing arrangement already creates a pronounced sense of enclosure. I am therefore not persuaded that the proposal would result in a significant additional loss of sunlight or outlook, or materially increase the sense of enclosure currently experienced.

Accordingly, in the absence of a reliable evidential basis to demonstrate material harm, I conclude that the proposed development would not harm the living conditions of the occupiers of No 24 having regard to sunlight, outlook and sense of enclosure. The proposed development would therefore accord with Policy D3 of the LP and Policy DM1 of the DMP, the aims of which have previously been set out, as well as the relevant guidance within the SPD.

Conditions requiring the development to commence within the statutory time limit and to be carried out in accordance with the approved plans are necessary to provide certainty and ensure compliance with the development plan. A condition requiring the external materials to match those of the existing building is necessary to safeguard the character and appearance of the area.

For the reasons given above, I conclude that the appeal should be allowed subject to the conditions listed in my formal decision.