Loft conversion to create a master bedroom, raising of the roof by 710mm, and insertion of dormer window to the rear

Appeal Decision Site visit made on 16 September 2025 by L Francis BA (Hons) MA MRTPI an Inspector appointed by the Secretary of State Decision date: 7th October 2025 Appeal Ref: APP/D3830/D/25/3368033 54-56 Oak Tree Drive, Hassocks BN6 8YD • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by Miss Lucy Black against the decision of Mid Sussex District Council. • The application Ref is DM/25/0147. • The development proposed is a loft conversion to create a master bedroom, raising of the roof by 710mm, and insertion of dormer window to the rear. Decision 1. The appeal is dismissed. Preliminary Matters 2. The description of development was amended by the Council in its decision letter. I have used this description in the banner heading above since it fully describes the alterations. Main Issue 3. The main issue is the effect of the proposal on the character and appearance of the area. Reasons 4. The appeal relates to a pair of semi-detached two storey dwellings set within a cul-de-sac within a residential development off Mackie Road. The dwellings in the immediate area are predominantly two storey houses with traditional brick elevations, some with hung tiles at first floor. Roofs are typically tiled, dual pitched and gable ended. There is no particularly consistent ridge height due to the variation in detailed design and style of the buildings. Where there is accommodation set within the roof storey, there are several examples of individual pitched roof dormer windows set within the roof slope. Rear dormers spanning the full width of the dwellings are, however, not a characteristic feature of the area. 5. The appeal proposal is for a loft conversion for each property, with a single large dormer to the rear roof slope of each house. To achieve sufficient headroom for the extension, it is proposed to raise the ridge of the roof by around 70cm. 6. The two proposed dormers would effectively add a second-floor rising sheer from the first floor. This would be a very dominant addition to each property, which would have the effect of making the dwellings appear top heavy and unbalanced. The bulk of the rear dormer to each property would be visible in glimpsed views from the street and in some very limited views from the path and field to the rear of the appeal site. Appeal Decision APP/D3830/D/25/3368033 2 7. Although there would be limited public views of the proposed extensions, they would nevertheless be at odds with the established character of the area due to the bulk and scale of the extension to the rear roof slope. The dormers would effectively obscure the rear roof slope and would not be visually subordinate. Given the scale, bulk and visual dominance of the dormers, the proposal would conflict with Principles DG49 and DG52 of the Mid Sussex Design Guide Supplementary Planning Document adopted 2020 (the SPG). These require extensions to be well integrated with the scale, form and massing allowing the original building to remain the dominant element of the property, and in the case of loft conversions, they should not be out of scale or character with the roofscape and proportions of a dwelling. Further, chapter 6 of the SPG specifically in reference to dormer windows states that they should be visually subordinate to the roof slope. 8. My attention has been drawn to other local examples of full width rear box dormers at roof level. Whilst there are some examples, including three that I viewed on Chestnut Drive and Badger Close, they are not characteristic of the area. 9. I note the appellant’s point that the reason the proposal could not be done pursuant to a lawful development certificate is due to the necessity of raising the roof ridge height. As such, there is no alternative ‘fall back’ position provided by the use of permitted development rights, which are subject to a more limited set of considerations than a planning application. Notwithstanding this, the appeal proposal falls to be considered under the policies of the development plan. 10. In conclusion therefore, the proposal would harm the character and appearance of the dwellings and surrounding area, contrary to Policy DP26 of the Mid Sussex District Plan adopted 2018 and Policy 9 of the Hassocks Neighbourhood Plan made in 2019, as well as the provisions of the SPD. These policies, taken together and amongst other things, aim to achieve high quality design and respect the character and scale of the surrounding buildings and landscape. Other Matters 11. The Council consider the proposal acceptable in terms of its effect upon the living conditions of neighbouring residents, parking provision and sustainability. I have no substantive evidence before me which would lead me to disagree. 12. The appellant indicates that the alternative suggestions put forward by the Council would not achieve the desired usable floorspace. Additionally, it is said the suggestion made for separate dormers set within the roof slope would be prohibitively expensive. Planning Balance and Conclusion 13. I acknowledge the proposal would offer benefits through the provision of an additional bedroom and bathroom, improving the internal layout and quality of accommodation available for current and future occupiers of the properties, and I give moderate weight to this benefit. The absence of harm to the living conditions of neighbouring residents, parking provision and sustainability is a neutral consideration. Whilst my attention has been drawn to the issues associated with the Council’s alternative suggestion, that is not a matter before me for determination. 14. However, I attach significant weight to the harm I have identified to the character and appearance of the area, which outweighs the identified benefits. Appeal Decision APP/D3830/D/25/3368033 3 15. The proposal conflicts with the development plan and the material considerations do not indicate that the appeal should be decided other than in accordance with it. For the reasons given above the appeal should be dismissed. L Francis INSPECTOR