Appeal 3355648

The appeal is allowed and planning permission is granted for single storey rear extension and roof extension to include side facing dormers at [site address] , Hertfordshire [postcode] in accordance with the terms of the application, Ref 6/2024/1524/HOUSE, subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this decision.

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

The development hereby permitted shall be carried out in accordance with drawing nos 1576_300 (“Site Location Plan”), 1576_302 (“Proposed Block Plan”), and 1576_320 (“Proposed Floor Plan’s & Elevation’s”).

The extension hereby permitted shall not be occupied until the windows on the side facing roof dormers hereby approved have been fitted with obscured glazing, and no part of those windows that are less than 1.7 metres above the floor of the room in which it is installed shall be capable of being opened. Details of the type of obscured glazing shall be submitted to and approved in writing by the local planning authority before the window is installed and once installed the obscured glazing shall be retained in perpetuity.

On 12 December 2024, a revised National Planning Policy Framework (the Framework) was published and corrected on 7 February 2025. There is no need to invite further comments from the Council or the appellant on the revisions as there are no fundamental changes relevant to the appeal before me.

The main issue is the effect of the proposal on the character and appearance of the host building and the wider area.

The site forms part of a residential area primarily comprised of detached dwellings. In the immediate vicinity of the appeal site, dwellings are predominantly bungalows with varying degrees of alteration, including roof dormers. The appeal property is reflective of this character. There are notable land level differences in the area with the appeal property sitting at a higher level than the opposite side of the road.

As presented in the evidence before me, the appeal property has already gained planning permission for further alterations and extensions, including the enlargement of the existing side roof dormer and an additional side roof dormer. This proposal seeks to extend the dwelling to the rear and create additional volume within the roof through larger side dormers on each roof slope.

The development proposed would include large flat roof dormers which would be a dominant feature of the roof. Given the land level differences in the area, the extent of the roof dormers would be prominent in the street scene. However, there are other examples of large roof dormers in the area, including on the opposite side of [address], and properties behind the appeal site on [address]. The Council contends that these were determined before the current local plan, including the Northaw and Cuffley Neighbourhood Plan (NCNP), specifically Policy D2 which expects consideration of design guidance set out within Appendix 2.

Significant weight must be given to the previous permission which exists on the site. This has already allowed side and front roof dormers of a significant scale. The impact of the development in comparison to the previous permission would be towards the rear of the site which holds less prominence. Whilst the bulk of the roof dormers, and to a lesser extent, the rear extension, would still be visible in the street scene, the effect on the character of the host dwelling would be similar to the scheme already approved.

The proposal does conflict with the design guidance of the NCNP which specifically discourages long ‘shed’ dormers. However, I consider that the stringent application of the guidance is disproportionate in this case. Other similarly scaled roof dormers in the immediate area are comparable to the appeal proposal and have already established a contribution to the character and appearance of the area, including in the immediate street scene. In this respect, the proposal reflects its spatial context and accords with Policy D2 of the NCNP as a whole.

The appeal proposal would not harm the character and appearance of the host building and the wider area. As such, it would comply with Policies SP1 and SP9 of the Welwyn Hatfield Borough Council – Draft Local Plan Proposed Submission 2016, and Policy D2 of the NCNP, that seeks, amongst other things, for proposals to relate well to their surroundings.

I shall impose a condition specifying the relevant drawings to provide certainty for all parties. A condition is necessary for materials to match those used on the existing house to maintain the character and appearance of the area. A condition requiring the windows in the side facing roof dormers to be obscurely glazed is necessary to prevent overlooking to neighbouring properties.

For the reasons given above, having regard to the development plan and all relevant material considerations, I conclude that the appeal should be allowed.