Appeal 3348975

The appeal is dismissed.

The Council’s officer report indicates that Barnet’s Draft Local Plan is presently at examination. However, I have not been notified that it has been adopted and I have had regard to current development plan policy in my decision.

The main issue in this appeal is the effect of the proposed development on the character and appearance of the area, including the locally listed buildings at 8 and 10 [site address] .

Located on [site address] ’s western side, [site address] forms one of a semi-detached pair with its neighbour at 10 [site address] . While it is generally residential in character, [site address] has a mixture of detached and semi-detached houses of varying architectural styles, sizes and ages. Beyond the neighbouring pair of semi-detached houses, there are terraced houses, blocks of flats, and [name].

Though not within a conservation area, Nos 8 and 10 are on Barnet’s Local Heritage List 2020 as a semi-detached pair of three-storey houses with two-storey side wings, front square bays with balustrade balconies above, and sash windows. They are locally listed for intactness, aesthetic merits and group value. All these factors indicate that Nos 8 and 10 have architectural interest.

Planning permission has been obtained to alter the existing rear extension (23/3291/HSE) and a certificate of lawful development has been granted for a replacement rear dormer window to the main roof (23/3161/192). No 8’s single storey rear extension was under construction at the time of my site visit.

Notwithstanding previous extensions and alterations to Nos 8 and 10, they retain a considerable degree of homogeneity, intactness, and group value as a pair. The side wings to Nos 8 and 10 retain considerable uniformity, evidenced by their matching size, roof line, roof height and pitch, and detailed design features. The main existing difference between the side wings at Nos 8 and 10 is a chimney which appears to have been partially removed from No 8. The main rear roofslopes at Nos 8 and 10 currently have two small dormer windows per property. There are no existing dormer windows to the side wings.

The proposed development would involve raising the pitched roof, partial chimney, and gable wall of the rearmost part of the two-storey side wing at No

Additionally, at the rear of the side wing, the eaves height would be raised to match the eaves height of the main roof and a flat roofed dormer window would be inserted in the side wing’s raised roof. A larger window would be introduced below the proposed dormer window at first floor level.

Policy CS1 of Barnet’s Local Plan Core Strategy (2012)(CS) seeks the highest standards of urban design, amongst other things. Meanwhile CS Policy CS5 outlines the Council’s approach to protecting and enhancing Barnet’s character, including locally listed buildings. Policy DM01 of Barnet’s Development Management Policies (2012)(DMP) also deals with character and states that proposals should preserve or enhance character and respect the appearance, scale, mass, height and pattern of surrounding buildings, spaces and streets. DMP Policy DM06 asserts that all heritage assets will be protected in line with their significance. It sets out expectations for how proposals affecting heritage assets will demonstrate their consideration of the relevant asset(s).

The Council’s Residential Design Guidance Supplementary Planning Document (2016)(SPD) sets out guidance on dormer roof extensions and other extensions. The SPD states that adequate roof slope above and below the dormer is required on semi-detached properties, and the dormer should be set in at least 1 metre from the party wall, flank wall or chimney stack.

The SPD also asserts that dormer roof extensions should normally be subordinate features on the roof and should not occupy more than half the roof’s width or depth. It goes on to confirm that to retain the house’s balance, the dormer roof extension should not normally be wider than the window below it and the dormer cheeks should be kept as narrow as possible. It confirms that the design should reflect the style and proportion of windows on the existing house. It recognises that dormers may have flat, gabled, hipped or curved roofs and should normally align with the windows below.

The SPD states that extensions should normally be consistent with the original building’s form, scale and architectural style which can be achieved through respecting the existing house’s proportions and using an appropriate roof form.

The increase in height of the side wing’s roof and raising of the partial chimney would serve to unbalance the consistency and inherent quality of the pair of houses at Nos 8 and 10. This would be visible from the streetscene along [site address] and would cause harm. Further alterations to the side wing’s rear roof, in terms of the eaves height and the dormer window, would reduce the uniformity of Nos 8 and 10’s rear elevations. The dormer window would be unduly large, occupying much of the roofslope. This would fail to be subordinate to the roof. Though there is variation in fenestration to the rear elevation of No 8, the proposed first floor window would appear at odds with other existing windows due to its width. Taken together, the proposed development would be harmful to the character and appearance of the locally listed buildings and the area due to its size, siting and design.

Paragraph 209 of the National Planning Policy Framework (December 2023)(NPPF) requires the effect of an application on the significance of a non-designated heritage asset to be taken into account in determining the application. In weighing applications that directly or indirectly affect non-designated heritage assets, a balanced judgement will be required having regard to the scale of any harm or loss and the heritage asset’s significance. While the proposed development would allow the occupiers to improve the quality of accommodation within No 8 and increase the size of their family home, this would have very little weight in contrast to the harm I have found.

[name] am aware of a rear dormer window to the main roof having been approved as permitted development, I have not been provided with approved plans and it was not present on site at the time of my visit. There are large dormer windows to nearby properties, but the host properties are not of the same architectural style as No 8. In any event, I am required to deal with the appeal before me on its merits.

The proposed conditions refer to policies that the Council has also used to refuse the application. However, this is not unreasonable as it is necessary for the Council to provide conditions as part of the appeal process, notwithstanding their refusal of the application.

In conclusion, the proposed development would have a harmful effect on the character and appearance of the area, including the locally listed buildings at 8 and 10 [site address] . It would conflict with [name] CS1 and CS5, [name] DM01 and DM06, and the SPD as outlined above. Reference is made in the Council’s officer report and the appellant’s statement to [name] DM02 and DM15. However, these policies are not directly relevant to this appeal and I have not concluded against them. The appellant has referred to multiple paragraphs of the NPPF in respect of sustainable development and design, but this does not alter my findings in respect of the development plan.

For the reasons given above, the appeal should be dismissed.