Construction of single storey rear and first floor side/rear extension, and conversion of loft to habitable room to include associated roof alterations, rear dormer, and 3x roof lights

Appeal Decision Site visit made on 21 June 2022 by A Hickey MA MRTPI an Inspector appointed by the Secretary of State Decision date: 8 July 2022 Appeal Ref: APP/N1920/D/21/3269454 29 Heath Drive, Potters Bar EN6 1EN • The appeal is made under section 78 of the Town and Country Planning Act 1990 against a refusal to grant planning permission. • The appeal is made by Mr Alan Millinder against the decision of Hertsmere Borough Council. • The application Ref 20/0764/HSE, dated 3 June 2020, was refused by notice dated 23 November 2020. • The development proposed is the construction of single storey rear and first floor side/rear extension, and conversion of loft to habitable room to include associated roof alterations, rear dormer, and 3x roof lights. Decision 1. The appeal is dismissed. Preliminary Matters 2. The description of development on the decision notice has been altered from the application form. The description on the decision notice more accurately describes the proposal. I have considered the appeal on this basis and amended the banner heading accordingly. Main Issue 3. The main issue is whether the proposal would preserve or enhance the character or appearance of the Potters Bar Darkes Lane West Conservation Area (CA). Reasons 4. The CA encompasses a residential estate, which is characterised generally by detached dwellings. The significance of the CA includes the varying house styles, spacious plots, reinforced by tree-lined grass verges, which separate the footways from the carriageways. Whilst some dwellings have made alterations to the roof, the form of the original roofs on most dwellings can still be understood as the overall shape has been retained. Consequently, the roofscape of the area adds to the architectural interest and character of the CA. 5. The host dwelling is a detached two-storey dwelling, with a hipped roof, a bay window and some modest architectural detailing on its front face, and a similar out-rigger feature on the rear elevation. Whilst individual in its style, like most dwellings on the street, it has retained much of its original character by way of materials, layout and historic boundaries. Consequently, although not locally listed the property makes a positive contribution to the character and appearance of the CA. Appeal Decision APP/N1920/D/21/3269454 2 6. Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 requires me to pay special attention to the desirability of preserving or enhancing the character or appearance of a conservation area. In this respect, national policy on heritage assets, which includes conservation areas, is set out in the National Planning Policy Framework 2021 (Framework). 7. Although replicating the eaves and ridge height of the existing property, the proposal would alter the shape of the main roof of the house and result in a large crown roof and a rear dormer. The dormer’s materials and the proportions of its windows would respect those in the host property. However, the appeal property has retained its original hipped roof form and a clear sense of proportions. Due to the bulk and scale of the proposed crown roof, the dwelling would appear unduly prominent within the streetscene. The altered roof would be clearly discernible from nearby plots and the street including over existing boundary treatments and landscaping. It would appear uncharacteristic and incongruous within its surroundings and harm the appearance of the host dwelling and wider CA. 8. There are limited examples of crown roofs to other properties in the CA including one located on the same side of the street at No 25. However, this is different in style being set below the existing roof, predominantly located outside of public view and partially screened by the roof slope of the host dwelling. The other example at No 32 has retained the original main roof form with the flat element only at the extension. Therefore, these existing developments are materially different to the appeal proposal. 9. The proposed single-storey extension to the rear would be screened from public view behind the host dwelling and existing boundary treatments. It would be constructed in materials to assimilate with the host dwelling. Additionally, the small scale of the dormer, its limited projection and use of matching materials would not harm the roof form of the host dwelling or the appearance of the CA. For these reasons these elements of the scheme would have a neutral effect on the CA. 10.The proposal would lead to less than substantial harm to the significance of the CA. The Framework indicates that such harm is to be weighed against the public benefits of a proposal. However, great weight should be given to an asset’s conservation. 11.The benefits of temporary employment whilst construction takes place would be small given the scale of the scheme as such, the public benefits do not outweigh the identified material harm to the designated heritage asset. 12.I, therefore, conclude that the development would fail to preserve or enhance the character or appearance of the CA. As such, it would be contrary to Policy CS14 of the Core Strategy (2013)1, SADM29 of the Site Allocations and Development Management Policies Plan and the Framework. These policies, amongst other things, seek to ensure that development should safeguard or enhance designated heritage assets. 1 Hertsmere Local Plan Development Plan Document Core Strategy Appeal Decision APP/N1920/D/21/3269454 3 Other Matters 13.Even if I was to agree there was no harm to living conditions to nearby occupiers this would be a neutral factor and would not overcome the harm to CA I have identified. 14.Whilst there would likely be some light escaping through the roof lights on the rear extension it is unlikely this would be significantly more than is already present on the rear elevation. 15.While the appellant has altered the scheme following pre-application advice and a previous application, I have found harm would arise from the appeal proposal. Conclusion 16.The proposal conflicts with the development plan when taken as a whole and there are no material considerations, either individually or in combination, that outweighs the identified harm and associated development plan conflict. 17.Therefore, I conclude the appeal should be dismissed. A Hickey INSPECTOR