Appeal 6008536

The appeal is allowed and planning permission is granted for residential ground floor rear / side extension to outrigger at [site address] , Bromley [postcode] in accordance with the terms of the application Ref 26/00452/HPA and the plans submitted with it, 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: 2027/209, 2027/210, 2027/220.

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 site benefits from an extant Lawful Development Certificate under reference 25/05728/LDC. That certificate establishes the lawfulness of single-storey development at the appeal property, including an infill element with a greater height to the top of a flat roof, albeit of reduced depth when compared with the appeal proposal. Concerns have been raised regarding the legitimacy of the certificate. However, there is no substantive evidence before me to indicate that it has been revoked, quashed, or otherwise rendered incapable of implementation. On the evidence before me, the certified development represents a realistic fallback position. I therefore attach moderate weight to it in respect of the extent of single-storey development that could lawfully take place at the appeal site and its relationship with neighbouring dwellings.

The main issue is the effect of the proposed development on the living conditions of the occupiers of [address] (No.79), particularly in terms of outlook.

The appeal property is a two-storey mid-terrace dwelling on the southern side of [address]. It has an existing two-storey rear outrigger, a common feature of this terrace. The adjoining properties, including 75 (No.75) and [address], retain a broadly comparable rear outrigger arrangement, although there are various single-storey rear and infill extensions elsewhere within the terrace and surrounding area. These vary in their detailed form, depth and roof design.

The proposal would infill the side return and provide a single-storey rear extension, so that the new addition would wrap around the existing outrigger. Along the common boundary with No.79, the extension would have a length of about 7.2 metres. The boundary wall would be about 2.43 metres above the adjoining ground level, with the roof then sloping away from the boundary.

The proposal would introduce built form along a boundary where the outlook from No.79 is presently more open. It would be visible from windows in the rear and flank elevations of that property. Given the relatively narrow side-return relationship between the outriggers, I accept that the proposal would change the outlook from No.79 to some degree.

Although the flank wall would be higher than a typical domestic fence, it would not be of excessive height in the context of the existing two-storey rear outrigger arrangement, the close-grained terraced form of development, and normal domestic boundary conditions. Importantly, the roof would slope away from No.79, reducing the visual mass of the extension as perceived from that dwelling.

While the length of development along the boundary would be appreciable, its height and roof form would limit its enclosing effect. The retained open aspect beyond and above the extension, particularly from the principal rear-facing outlook of No.79, would further moderate its effect. I am not persuaded that the proposal would create an unacceptable sense of enclosure, tunnel effect or an unduly overbearing relationship.

I also attach weight to the fallback position. I acknowledge that the certified development is not identical to the appeal proposal. It would have a different configuration and would not be a full replication of the wraparound form now before me. However, the fallback would itself introduce single-storey built form close to the same neighbouring outlooks and within the same rear/side relationship. It therefore shows that the outlook from No.79 is not one which would necessarily remain unaffected by lawful development at the appeal site.

The Council’s Urban Design Guide Supplementary Planning Document (2023) advises that extensions should avoid uncharacteristically large additions that harm neighbouring amenity. However, that guidance must be applied having regard to the specific circumstances of the site. In this case, when noting the height, roof form sloping away from No.79, the existing outrigger relationship, and material fallback position, I find that the proposal would therefore accord with the broad amenity objectives of the guidance.

The Council did not find that the proposal would result in any unacceptable loss of light to No.79. Based on the evidence before me, and having regard to the height, siting and roof form of the proposed extension, I see no reason to reach a different

I therefore conclude that the proposal would not unacceptably harm the living conditions of occupiers of No.79, having had particular regard to outlook. As such, the proposal would not conflict with Policy D3 of the London Plan (2021) or Policies 6 and 37 of the Bromley Local plan (2019), which amongst other matters, require development to be of a high standard of design, provide appropriate outlook and be compatible with surrounding development.

The Council concluded that the proposal would not have an unacceptable impact on the living conditions of the occupiers of No.75. Based on the evidence before me and my observations on site, I find no reason to disagree. The proposal would not project significantly beyond the rear of No.75 and would not result in unacceptable dominance, enclosure, loss of outlook or loss of light to that property.

Concern has been raised regarding noise and disturbance. The proposal is a domestic extension to an existing dwelling. Construction activity would be temporary and subject to normal controls. Once completed, the development would not introduce a materially different or more intensive residential use. I therefore find no unacceptable harm in this respect.

I have considered the conditions suggested by the Council against the tests of paragraph 57 of the National Planning Policy Framework and advice in the Planning Practice Guidance: Use of planning conditions. In addition to the statutory time limit condition, a condition specifying the relevant plans is necessary to provide certainty. A condition requiring the external materials to match those of the existing dwelling is also necessary to ensure a satisfactory appearance.

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