Appeal 3349267

The appeal is allowed and planning permission is granted for the erection of a single-storey rear extension and excavation of a basement at [site address] , Lambeth, London, [postcode] in accordance with the terms of the application, Ref 24/01399/FUL, 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 approved plans: Site Location Plan at scale 1:1250 and [name] 2024-113-01A [name], 2024-113-02 and 2024-113-03.

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 basement extension hereby approved shall be carried out in complete accordance with the details and measures contained within the Basement Impact Assessment GWPR5749/BIA/December 2023 prepared by Ground & Water.

The flat roof element of the single-storey rear extension hereby permitted shall not be used as a roof terrace, sitting out area or other amenity space.

The planning application was made in the name of [name]. The appeal was lodged in the name of [name] with [name] name given as the agent for the appeal on the appeal form. It is only the applicant who has the right of appeal. The appeal cannot be transferred to another person and therefore the appeal has proceeded in the name of [name].

The main issue is the effect of the proposal upon the character and appearance of the host property and the wider [address] Conservation Area.

The appeal property is a two-storey detached house with accommodation in the roof and basement. It is part of a small original group of decorative, late- Victorian houses to this side of the road. The property sits within the [address] Conservation Area (CA); a wide and leafy suburban road of detached and semi-detached properties which are principally a reflection of the changing house styles from the period between around the 1840’s up to the early 1900’s. The appearance of No [address] scene, together with its large rear garden and mature planting, contributes positively to the CA’s architectural quality and spaciousness.

The dwelling is formed with a gabled cross wing. The rear gable spans almost half the width of the dwelling with an existing single-storey, flat roof extension to the rear and which extends sideways and partially wraps around the dwelling’s side elevation adjacent to [address]. The proposal seeks to fill the void between the existing extension and the boundary with No 41, effectively projecting a remodelled form of the existing extension across the full width of the property, but with a slight recess part way along its façade.

The gardens to the properties along this side of [address] are large and leafy, contributing to the area’s spacious qualities. However, due to the seclusion offered by the dense and mature vegetation around No 39’s garden perimeter, which is typical for the area, the rear elevation of the building is largely out of sight beyond the confines of the property’s curtilage. Given this, and having regard to the existing rear extension, I do not consider the rear elevation of the appeal property to be overly sensitive to further change.

The Lambeth Design Guide SPD Part 4: Building Alterations, Extensions and Retrofit does not rule out the principle of a full width rear extension across a dwelling, even within conservation areas. It does however identify that subordination is key and that refinement of form and treatment may be required to lessen any boxy horizontal effect.

In my assessment, the increased width to the existing extension would not fundamentally change the relationship it has to the host dwelling. At single-storey height, and with a depth equivalent to the existing, the remodelled extension would remain subservient to the scale and form of the original dwelling. I find nothing about the proposed extension’s scale or proportions that would appear overly dominant or incongruous in relation to the evolved appearance of the property within its rear garden setting. I accept that the step to the elevation would be modest, but it would nevertheless add a degree of articulation that would serve to break the horizontal emphasis of the addition.

Overall, I am satisfied that the changes to the rear of No 39 would not detract from the character or appearance of the dwelling. In these circumstances it follows that the character and appearance of the CA would be preserved. As such, its significance as a designated heritage asset would be unaffected. There would therefore be no conflict with Policies Q5, Q11 or Q22 of the Lambeth Local Plan 2020–2035 (LLP), adopted in 2021, which between them seek to ensure that new development responds positively to and respects the area’s local distinctiveness, including the positive characteristics of a conservation area and the architecture of the original building. For the same reasons I find no conflict with the National Planning Policy Framework’s objectives for achieving well-designed and beautiful places and for conserving and enhancing the historic environment.

I have carefully considered the concerns raised by neighbouring occupiers.

The application was accompanied by a scoping and screening Basement Impact Assessment (BIA), which was based on the application drawings. The Council’s officer’s report confirms that the BIA satisfies the requirements of LLP Policy Q27 which deals with basement development and its implications. I have been provided with no evidence to dispute this assertion. Neither have I been provided with any evidence relevant to the planning merits of the case to demonstrate that further details are required.

The application was accompanied by the results of a Building Research Establishment compliant daylight/sunlight study. The results of the study demonstrated that the proposed extension would not unacceptably affect the daylight and sunlight received through any neighbouring windows. At single-storey height and of a depth that would not be excessive, I am satisfied that there would be no effect upon the living conditions of any neighbouring occupiers in terms of visual intrusion or overbearing impact. The use of the extension and enlarged basement for residential purposes would not generate any levels of noise beyond that associated with any typical residence.

My findings on these matters are consistent with the Council’s.

The officer’s report refers to some suggested conditions had the application been considered acceptable to the Council. The Council has also suggested conditions in the event of the appeal succeeding. I have considered these in light of advice in Planning Practice Guidance and the National Planning Policy Framework.

A condition specifying the relevant plans is necessary as this provides certainty. In order to safeguard the character and appearance of the area a condition is required to ensure that the development is finished in materials to match the existing dwelling.

In order to safeguard residential amenity, I agree with the Council that a condition is required to ensure the basement development follows the recommendations of the BIA. To avoid the potential loss of privacy for neighbouring occupiers I agree with the comments within the officer’s report that a condition is required to restrict use of the flat roof over the rear extension.

Given the domestic scale of the development, I do not consider any hazards or obstruction would be caused to users of the public highway or nearby residents from vehicles or plant associated with the development, or that air quality would be materially affected. Conditions relating to these matters would therefore be neither reasonable nor necessary.

For the reasons given, I have found that there would be no harm to the character or appearance of the host property or to the wider [address] Conservation Area. Accordingly, in the absence of any other conflict with the development plan, and having regard to all other matters raised, the appeal is allowed.