Appeal 6001424

The appeal is allowed and planning permission is granted for excavation of new single storey basement level, to the rear of the existing garden at [site address] in accordance with the terms of the application, Ref 25/02319/FUL, and the plans submitted with it, 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 drawing nos. [name]; 101A [name]; 102; 103; 200L [name]; 201L [name]; 202L [name]; 203L [name]; and 204L [name].

The basement excavation hereby approved shall be carried out in accordance with the details and measures contained in the Structural & [name] dated 13.08.2025; and the Method of [name].

The main issue is the effect of the proposed development on the character and appearance of the host dwelling.

[site address] (No 45) is a three-storey semi-detached dwelling with a front elevation which is traditional in character and typical of other dwellings along this part of [address]. To the rear, it has a ground floor and mansard extension and other alterations which are modern in their design and detailing.

It is proposed to excavate a single-storey basement which would extend the width of the rear part of the garden of No 45, but consistent with the [name] 5: Basements (2023) (LDG) it would retain no less than 70% of the rear garden free of basement development and at its original ground level. The basement would be accessed via an external staircase which, whilst projecting part way across the width of the garden, would be relatively narrow in depth. It would have a simple, black metal handrail and the basement would have a glazed lightwell flush with the garden, which together would respond appropriately to the modern character and materials of the rear elevation of No. 45.

Given the largely subterranean nature of the proposed works, they would have a negligible visual presence. The staircase opening, handrail and glazing would be seen from the first and second floor windows of neighbouring dwellings. However, these would be viewed from an elevated position and in the context of intervening landscaping, other outbuildings and garden paraphernalia. Accordingly, the above ground elements would not appear a particularly alien or obtrusive addition or feature to the rear of No 45, despite not being commonly seen in other gardens.

If both were built, the proposed basement would sit below the footprint of a single-storey garden outbuilding,1 but they would not be connected internally. The front staircase to the basement would not markedly add to the bulk or footprint of this outbuilding and, even when viewed together, they would appear only single-storey and would be of a proportionate scale to No 45 and its garden.

I therefore conclude that the proposed development would not cause harm to the character and appearance of the host dwelling. Consequently, it would accord with policies Q2 and Q14 of the Lambeth Local Plan (2021) in so far as they seek to ensure that development is subordinate in scale to the host building and visual amenity from adjoining sites is not unacceptably compromised.

In addition to the standard time limit condition, I have imposed a condition requiring that the development is carried out in accordance with the approved plans for the avoidance of doubt and in the interests of certainty. Given the very limited amount of above ground development, it is not necessary to require the external materials to match those used in the existing dwelling.

The Council was satisfied that the information submitted with the application confirmed the development would not result in an unacceptable risk to ground water, slope stability, surface flow and flooding. However, to minimise the impact on neighbours and ensure land stability, it is necessary to impose a condition which requires the procedures and method statement set out in the Structural and [name] and Method of [name] to be followed.

For the above reasons, the proposal accords with the development plan and there are no material considerations to indicate a decision should be taken other than in accordance with it. Therefore, I conclude that the appeal should be allowed.