Appeal 6004324

The appeal is allowed and planning permission is granted for a first-floor rear extension at [site address] , Barnet, Edgware, [postcode] in accordance with the terms of the application 25/4603/HSE 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 undertaken in accordance with drawing no.s JNDS-11-09-25-AA, 3D- JNDS-11-09-25-CC, JNDS-11-09-25- BB, JNDS-11-09-25-A11, 3D - JNDS-11-09-25-C11 and JNDS-11-09-25-B11

The external materials of the extension hereby permitted shall match those used in the existing dwelling.

The main issue is the cumulative effect of the proposed extension on the character and appearance of the host property and the surrounding area, with particular regard to its size, siting, design and height.

The appeal property is a semi-detached dwelling situated in [address], an established residential area characterised predominantly by inter-war suburban housing. It originally formed part of a pair of [name] style houses incorporating rendered elevations, a hipped roof form and period ‘Crittall’ windows, including a distinctive curved bay to the front elevation. The property is included on the Council’s Local List.

However, since its original construction, the dwelling has been altered through the addition of a hip-to-gable roof enlargement and a rear dormer extension, together with the replacement of the original windows. As such, the appeal property has Appeal Decision: 6004324 already undergone notable alteration to elements that contributed most strongly to its architectural interest.

Surrounding development is residential in character and comprises similar semi-detached dwellings of comparable scale and form arranged along a consistent building line. Many rear elevations within this part of the street, including those at the appeal property and its immediate neighbour, have already been altered through extensions. Rear extensions form part of the prevailing pattern of development.

Planning permission is sought for a first-floor rear extension positioned above the existing ground-floor rear projection. It is proposed that the extension would have a flat-roof and would be set below the eaves of the existing dwelling, infilling part of the rear roof slope adjacent to the recently constructed roof enlargement. The extension would align with the established rear building line and be constructed in materials to match the existing property.

The Council considers that, when taken together with the recently constructed roof extension, the proposal would result in an excessive level of cumulative development. The Council considers this would appear overly dominant and insufficiently subordinate to the original building, resulting in harm to the character and appearance of the host dwelling and its surroundings.

[name] recognise that the proposal would introduce additional built form when considered alongside the recently constructed roof extension, it would remain confined to the rear elevation and positioned above an existing projection. It would not materially alter the principal elevation or overall appearance of the dwelling when viewed from the street, nor would it erode any features of architectural significance.

Taking these matters together, I do not find that the cumulative effect of the proposed extension and the recently constructed roof enlargement would appear visually dominant or incongruous, nor that it would result in harm to the character and appearance of the host dwelling or the surrounding area.

I therefore conclude that the proposal would accord with Policy D3 and HC1 of the London Plan (2021), which require proposals to respond to existing character and conserve heritage significance, and Policies CDH01, CDH05 and CDH08 of the Barnet Local Plan (2025), which seek to promote high quality development, subordinate extensions and safeguard Barnet’s heritage.

The conditions imposed are those which have been suggested by the Council, with some wording changes for clarity and brevity. In addition to the standard time limit condition, I have imposed a condition requiring the development be carried out in accordance with the approved plans in the interests of certainty. A condition requiring the external materials to match those of the existing dwelling is necessary in the interests of safeguarding the character and appearance of the host dwelling and surrounding area. Appeal Decision: 6004324

For the reasons outlined above, and taking into account all other matters raised, I conclude that the appeal should be allowed.