Appeal 3356344

The appeal is dismissed.

There is one main issue which is the effect of the proposed extension on the character and appearance of the host dwelling and the surrounding area which lies within the [site address] Conservation Area (CA).

The appeal dwelling, which lies within the [site address] CA, is one of a pair of large, handsome semi-detached houses built between 1897 and 1914. It lies within a row of very similar dwellings that, from the street, retain a strong sense of uniformity and mirroring between the pairs. The dwellings have 2.5 storeys and are constructed in red brick with some rendering. The street, which is spacious and verdant, rises gently but the appeal dwelling and its neighbours are built on noticeably sloping land such that the ground floor sits above a semi-basement at the rear, and the long rear gardens fall away from the dwellings. At the appeal dwelling, French doors open onto a raised terrace that occupies the width of the rear elevation and has stairs down to garden level. This appears to be a modern wooden structure, supported on brick pillars. The appeal dwelling and a majority of its similar neighbours have side/rear extensions at ground and basement level. Some also have rear extensions of various sizes and designs.

The National Planning Policy Framework (NPPF), 2024, makes clear that conservation areas are designated heritage assets. When considering the impact of a proposed development on the significance of a designated heritage asset, the NPPF advises that great weight should be given to the asset’s conservation. Significance can be harmed through alteration of the heritage asset or development within its setting. Statutory protection is provided by Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (the 1990 Act). This requires that special regard/attention is paid to the desirability of preserving or enhancing the character or appearance of the heritage asset, including its setting. Relevant policies set out in the Council’s Local Plan and in particular Policy DM44 of the Development Management Document (DMD), 2014, accord with the NPPF in respect of heritage assets.

The appeal proposal comprises an extension that would sit adjacent to the existing rear/side extension and occupy about half the width of the original rear elevation of the dwelling. It would have a hipped roof that would finish just below first floor cill level. Its footprint would be modest, and I saw other rear extensions on other similar dwellings nearby, including the attached pair.

Nevertheless, the proposed addition would be disproportionately tall, extending from garden level to just below first floor cill level. It would cut across the floor and ceiling levels of the ground floor which would result in an awkward and discordant relationship with the host dwelling and in particular the original rear elevation. Its proportions and detailed design, including eaves, ridge height and fenestration, would jar with those of the original dwelling and it would unsympathetically mask the original rear elevation.

Moreover, the rear terrace would be completely lost and whilst the modern structure is of limited merit, it provides a visual divide between the ground floor and semi-basement which is important in maintaining the vertical balance and proportions of the rear elevation. Overall, the proposed extension would have a poor relationship with the existing dwelling that would be harmful to its character and appearance and would fail to preserve or enhance the character or appearance of the CA. In consequence, the significance of the heritage asset would be diminished.

I note the appellant’s evidence regarding the ways in which the proposed extension has been re-designed following an earlier scheme that was refused and dismissed on appeal (APP/Q5300/D/21/3283555), its position to the rear and hence not visible from the street, the difficulties posed by the sloping nature of the ground and the fact that the extension would improve the indoor space for occupiers. However, none of these matters would outweigh the harm identified.

Nevertheless, the harm that would arise to the CA would be less than substantial within the meaning of Paragraph 214 of the NPPF. The harm must therefore be weighed against the public benefits of the proposed development. However, these would be negligible, being limited to the small economic benefit of construction.

Overall, I therefore find that although there would be private benefits, as identified by the appellant, the public benefits would be limited. As a consequence, they would not outweigh the great weight that should, in accordance with the NPPF, be given to the conservation of the CA as a designated heritage asset.

It is concluded on the main issue that the proposed extension would have a materially detrimental effect on the character and appearance of the host dwelling and that the character or appearance of the [site address] CA would not be preserved. In consequence, the proposed extension would, in the context of strategic policies set out in the London Plan, 2021, conflict with Policies CP30 and CP31 of The Enfield Plan Core Strategy 2010-2025, adopted 2010, [name] DMD11, DMD44 and DMD37 and [name]-5 and HW-12 of the [site address] Neighbourhood Plan (2023). Taken together and amongst other things these expect new development to be of a high quality, having regard to its context, be of an appropriate scale, design and detailing and to conserve and enhance the special interest, significance or setting of a heritage asset. It would also conflict with the NPPF, 2024.

For the reasons set out above and having regard to all other matters raised, I conclude that the appeal should be dismissed.