Appeal 3277103

The appeal is dismissed.

I have used the Council’s description of the development in reaching my decision as it more fully describes the details of the development than that given on the original planning application form. The appellant’s appeal form also makes reference to the updated description.

The main issue is the effect of the proposed development on the character and appearance of the host property and the area.

The appeal property is a two storey extended detached dwelling with a distinctive double projecting front gable and a hipped and part crowned tiled roof. It is located in a mature well-established residential area characterised by large detached properties of different styles and designs set back from the road within relatively spacious landscaped plots. A number of the dwellings have crowned roofs and some dormer extensions of varying styles and designs that generally appear as clearly subordinate to the dwellings.

The appeal proposal would entail a loft conversion and roof alterations including the raising and replacement of the existing hipped and part crowned roof with a wider, crowned and hipped roof with two new side dormers, a single rear dormer and front/side rooflights. The side and rear flat roofed dormers would be inset from the edges and eaves of the roof and stepped down below the ridge line of the host property.

Although the use of a crowned roof and dormer extensions would not be materially harmful or undesirable in the streetscene in this suburban area, the scale and form of the new crowned hipped roof and dormers extensions would nevertheless result in significant additions relative to the main property. As such, although set in and stepped down, the proposed side and rear dormers, combined with the enlarged crowned hipped roof, would result in substantial bulk at the side and rear of the main dwelling that would be out of character with the more modest form and appearance of the host building.

These shortcomings are exacerbated by the proposal’s position, which would be visible from a number of public vantage points along [address]. The proposed dormer roof extensions and roof alterations, by virtue of their scale, siting and design, would fail to achieve an appropriate degree of subordination to the host property and would detract from the architectural integrity of the host property. As such, I consider that the proposed dormer extensions and roof alterations would result in incongruous and out-of-keeping additions that would cause unacceptable harm to the host property and the area.

I have considered the appellant’s arguments that the design and layout of the proposed dormer extensions and roof alterations have been carefully considered in order to take into account the character of the host property and other roof extensions and alterations in the area. Whilst the use of matching materials and fenestrations would assist in integrating the proposed dormer extensions and roof alterations with the host property and the area, these aspects again do not overcome the adverse effects outlined above.

Consequently, I conclude that the proposed development would have a harmful effect on the character and appearance of the area. It conflicts with the design aims of Policy CS22 of the Hertsmere Local Plan Development Plan [name] 2013, Policy SADM30 of the Site Allocations and Development Management Policies Plan 2016 and [name] of the Council’s Planning and Design Guide Supplementary Planning Document 2006. These policies and guidance, amongst other things, seek to ensure that new development proposals are of a high quality design that make a positive contribution to the built environment, recognise and complement the particular local character of the area and respect, enhance or improve the visual amenity of the area by virtue of their scale, mass, bulk, height and form. The main parties refer to the Radlett Neighbourhood Plan, but no detailed policies have been submitted as part of the supporting evidence to allow me to make a judgement on their relevance to this case.

It would not accord with the aims of the National Planning Policy Framework that seek to ensure developments secure a high quality of design (paragraph 126); that are sympathetic to local character (paragraph 130).

I have noted the other developments in the area drawn to my attention by the appellant. However, the various roof extensions and alterations on the properties within the surrounding area have different development characteristics to the appeal scheme. In any event, each proposal falls to be assessed primarily on its own merits and I am unaware of the full circumstances associated with these other cases.

I have considered the appellant’s arguments regarding the type of extensions and roof alterations that can be erected on a dwellinghouse under General Permitted Development Rights. Whilst this may be so, this does not set a precedent for such an inappropriate development in this location for the reasons set out above.

I have considered the appellant’s statement on the fall-back position on the appeal site, including case law1 and the appellant’s options to build the dormer extensions using permitted development rights. Based on the evidence before me, there is a reasonable likelihood that the dormer extensions would be built if this appeal is dismissed. Be that as it may, in my view, the scale and form of such a development would not be as substantial as the proposal now before me and would have more limited impact on the character and appearance of the host property and the area. I therefore accord these matters moderate weight in making this decision.

I have considered the various benefits put forward by the appellant that the proposal would bring including the scheme’s high quality design and to create additional accommodation to meet the needs of the appellant. [name] have given them some weight, these benefits would not be sufficient to outweigh the harm I have identified. For all these reasons, there are no other material considerations to outweigh the development plan conflicts identified.

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