Appeal 3340567

The appeal is allowed and planning permission is granted for a ‘side and rear extension with 5 rooflights, including a garage conversion with a replacement garage door, replacement front door, replacement of main roof tiles, replacement windows to rear facade to a Juliet balcony on the first floor with associated external alterations’ at [site address] , Plumstead, London [postcode] in accordance with the terms of the application, Ref 23/3858/HD, 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: HV-R00-EX-102, HV-R00-EX-103, HV-R00-EX-104, HV-R00-EX-105, HV-R00-EX-106, HV-R00-PR-101, HV-R00-PR-102, HV-R00-PR-103, HV-R00-PR-104, HV-R00-PR-105 and HV-R00-PR-106.

The external surfaces of the development hereby permitted shall be constructed in the materials shown on plan [name]-R00-PR-103, HV-R00-PR-104 and HV-R00-PR-105.

The description of development entered on the planning appeal form is consistent with the description stated on the Council’s decision notice. [name] consider this to describe the proposal more fully and accurately than the description originally given on the planning application form and it has been used by both main parties, I have also used it in the banner heading and my formal decision above.

The main issue is the effect of the proposal on the character and appearance of the host dwelling and the Plumstead Common Conservation Area (‘the CA’).

The Plumstead Common Conservation Area: [name] 2010 (‘the CACA’) indicates that the CA was designated to protect and enhance an area of ancient common land together with buildings on its periphery which frame views across the Common and contribute to its setting. The CACA notes that the buildings fronting onto the Common are mainly two-storey late 19th century terraces, and that while many are architecturally typical rather than special, they have group value and the open setting of long lines of typical Victorian houses enhances their townscape character. Insofar as it relates to this appeal, I consider that the significance of the CA is primarily associated with the consistency in the traditional form and detailing of the buildings around the Common, together with the quality of many of the buildings themselves which provide for an attractive and distinctive sense of coherence.

The appeal relates to a semi-detached dwelling which overlooks [name]. The dwelling has a simple pitched roof form with dormers to the rear and includes a part two-storey, part single-storey rear outrigger and a garage to the side. Though of relatively modest overall appearance, decorative mouldings above the ground floor window and the arch to the recessed porch entrance at the front of the building add architectural interest.

These details are common to the attached neighbour at 1 [name] and the adjacent pair at 3-4 [name]. However, while of generally similar overall design to one another, No 1 is markedly wider than other dwellings in this group and other alterations are apparent including a rear conservatory to No 1 and a set back two-storey projection to the side of No 3. Furthermore, the neighbouring semi-detached pair at 1-2 [address] are of different design, including parapet walls and prominent two-storey canted bays, 5 [name] is a detached dwelling with a hipped roof and beyond No 5 are three-storey modern flat-roof blocks. Although outrigger projections are a common feature to dwellings in the area, there is notable variety in the appearance and the pattern of development on [name] and the street scene lacks a strong sense of continuity or uniformity. Nevertheless, insofar as the traditional form and detailing of the appeal dwelling is typical of the CA and the frontage is part of the framing to [name], I find that it contributes to the character and appearance and thus the significance of the CA.

The Council considers that the alterations proposed to the front of the property including the replacement garage doors and front door and the alterations to openings to the side and rear of the building would be acceptable. Based on my observations, I agree and I find that these elements of the proposal would preserve the character and the appearance of the dwelling and CA. The slate roof that is proposed to replace the existing tiles would reflect common roofing materials within the CA. It would also match the roof of the attached neighbour at No 1, bringing greater uniformity to the pair, including in views from the street and [name]. In this regard, there would be some, albeit very modest, enhancement to the character and the appearance of the CA.

The appeal also proposes alterations to the garage to the side of the dwelling and the addition of an extension to its rear which would wrap around the rear of the dwelling to the same depth as the two-storey part of the outrigger.

The hipped roof that is proposed to the garage and extension would differ from the dwelling’s pitched main roof and the monopitched outrigger roofs. However, I saw that there are already hipped roofs to the dormers to the rear of the dwelling. Moreover, the garage currently has a flat roof behind a false pitch. This would be replaced so that the overall number of different roof forms on the site would actually be reduced. Although the extension roof would not match the pitch of the original dwelling, I am satisfied given these factors that its form would not be jarring or unsympathetic against the dwelling. Given also the existing variety in roof forms already present along [name], including of projections to the side of buildings, the hipped roof would not stand out in the street scene.

The apex of the roof would be fairly high, sitting above the sill of a first-floor window to the rear of the outrigger. This would be contrary to guidance in the Urban Design Guide Supplementary Planning Document 2023 (‘the UDG’) that the roof line of extensions should generally be 300mm below the first-floor window sill. However, the UDG recognises that this cannot always be achieved. In this case, the roofline would be below the sill of the first-floor windows to the front of the dwelling and the relationship with windows to the rear would not be appreciable in public views, including from the street or [name]. The roof would fall significantly towards the eaves so that clear spacing to the boundary with No 3 would be maintained at first-floor level and above and the development would also be lower than the two-storey side projection to No 3 which although set back, is appreciable. In this context, I find that the height of the extension would not appear dominant or inappropriate in the street scene and framing views of the Common would not be harmed.

The position of the extension sitting between the two-storey outrigger of the appeal dwelling and the two-storey projection to the side of No 3 further means that other opportunities for views of the development, including from surrounding properties would be very limited. Even where it would be seen, the development would be set well down from the eaves of the roof to the two-storey part of the outrigger, and even further below the eaves of the main roof. The height at the eaves would also be modest, and the overall bulk and mass of the roof would further be significantly reduced by the hipped form.

The depth of the extension beyond the main rear wall of the dwelling would slightly exceed the 3.6m that the UDG indicates is typically considered appropriate, and the depth beyond the garage would be greater. However, the UDG comments that projections beyond this can be considered for certain typologies where neighbourly amenity is not compromised. In this case, I agree with the Council that neighbouring amenity would not be harmed. Moreover, the rear wall of the extension would be no deeper than the two-storey part of the outrigger, and there would remain a pronounced set-back from the single-storey part. The dwelling would also retain a generous rear garden.

I acknowledge that the extension would wrap around to the side of the building, but I am satisfied that the original form of the dwelling, including its stepped form with outrigger, would remain readable. Even in combination, I consider that the height, width and depth of the development would not appear excessive against the dwelling or site. In my judgement, the development would be suitably subordinate in scale and appearance and I find given the above factors that it would integrate well with the dwelling without dominating or overwhelming its form or character.

The Council suggests that while infill extensions are common in the vicinity of the appeal site, there are none of the same scale and size as that proposed. Be that as it may, I have already noted existing variety as a feature along [name], and this includes the markedly greater two-storey width of the attached neighbour at No 1. Against this variety and given the lack of visibility of the rear part of the development and my findings above, the proposal would not harmfully disrupt townscape continuity or a uniform development pattern which makes a positive contribution to the CA.

I have paid special attention to the desirability of preserving or enhancing the character or appearance of the CA in accordance with s72 of the Planning (Listed Buildings and Conservation Areas) Act 1990. The proposal would not accord in all respects with detailed guidance in the UDG. However, the guidance is just that and while it may provide an indication of harm, this is not an inevitable conclusion should a proposal not accord with its provisions. For the reasons above, I am satisfied that the development would sit comfortably on the site and within the CA.

I conclude in the specific circumstances of this case that there would not be unacceptable harm to the character or the appearance of the host dwelling and that the character, appearance and significance of the CA would be preserved. Accordingly, a departure from the detailed guidelines within the UDG is justified and I find no conflict with Policies D3 or HC1 of the London Plan 2021 or Policies DH1, DH3, DH(a) or DH(h) of the Local Plan Core Strategy 2014. Together, these policies include requirements broadly seeking high quality design, development that responds positively to local distinctiveness and character and that conserves and enhances heritage assets, and extensions of appropriate scale and design. The proposal would also accord with objectives in the CACA and Plumstead Common Conservation Area Appraisal and Management Plan 2010 seeking preservation and enhancement of the CA, and with the National Planning Policy Framework insofar as it seeks well-designed places and the conservation and enhancement of the historic environment.

In addition to the standard time limit condition, I have imposed a condition specifying the approved plans for the avoidance of doubt and in the interest of certainty. A condition controlling external materials is necessary to ensure a satisfactory appearance. Given though that the proposal includes alterations to the existing roof materials, I have amended the Council’s suggested condition to require use of materials as specified on the plans rather than matching materials.

For the reasons given above, I find that the proposal would accord with the development plan when it is read as a whole, and material considerations do not indicate that a decision contrary to the development plan should be reached.

I therefore conclude that the appeal should be allowed.