Appeal 6004076

The appeal is allowed and planning permission is granted for erection of a hip-to-gable roof extension including 2x front dormers, 1x rear dormer, to convert existing studio flat into a 2 bedroom (3 person) flat including associated parking, landscaping, bin and cycle store works at [site address] in accordance with the terms of the application, Ref 65765/APP/2025/2605, subject to the following conditions:

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

The development hereby permitted shall be carried out in accordance with drawing nos 300 [name] + Block Plan As Proposed; 301 [name] / Landscape Plan As Proposed; 302 [name] Plan As Proposed; 303 [name] Plan As Proposed; 304 [name] [name]; 305 [name]; 306 [name]; 307 [name] 3D Views and 308 [name]

The development hereby permitted shall not be occupied until details of accessible covered and secure cycle storage have been submitted to and approved in writing by the Local Planning Authority. The cycle storage shall be completed in accordance with the approved details before the use is commenced and retained thereafter for use by cyclists.

Notwithstanding the description of development set out above, which is taken from the application form, it is clear from the plans and accompanying details that the development comprises the erection of a hip-to-gable roof extension including 2x front dormers, 1x rear dormer, to convert existing studio flat into a 2 bedroom (3 person) flat including associated parking, landscaping, bin and cycle store works. The Council dealt with the proposal on this basis and so shall I.

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

The appeal property is a semi-detached bungalow which has been extended into its roofspace and comprises 4 flats. A hipped roof covers the majority of the property, with a front gable shared by the adjoining [address]. Existing dormers to the front and rear of the appeal property serve the first-floor studio flat. Although the appeal property uses similar materials to No 54, the properties have contrasting roof forms, with the roofscape of No 54 dominated by the shared front gable. A side dormer is also present at No 54. Therefore, the appeal property is not symmetrical in appearance with its semi-detached neighbour.

The property is located within an area which is residential in character, predominantly comprising gable fronted bungalows. I observed during my site visit that the surrounding built form includes many examples of dwellings which have been extended including through side dormer extensions of varying scales and a limited number of front dormers. In addition, there are examples of properties with side gables and which have been subject to hip-to-gable extensions. I do not have details before me of the planning history of these properties and, as such, the extent to which extensions have been undertaken using permitted development rights is unknown. Nevertheless, as result of the various extensions, the roofscape in the surrounding area lacks uniformity, notwithstanding the common occurrence of front gable roof forms.

Policy DMHD 1 of the Hillingdon Local Plan Part 2 – Development Management Policies (adopted 2020) (the LPP2) specifies that roof extensions should be located on the rear elevation only, be subservient to the scale of the existing roof and not exceed more than two thirds the average width of the original roof. The policy also states that the Council will not support poorly designed or over-large roof extensions including proposals to convert an existing hipped roof to a gable.

The proposed development would appear subservient to the main building and respect its original design, including by being of a scale proportional to the existing roof, retaining the pitch of the existing roof and aligning with the existing ridge height. The proposed dormers would be reasonably modest in scale and of consistent proportions and materials as the existing side dormer at No 54. As such, even though the roofscape of the appeal property would change considerably as a result of the development, the roof of the appeal property and the adjoining No 54 would be visually coherent, with the shared front gable remaining the dominant feature. In this regard, and taking into account the varied roofscape of the surrounding area including multiple examples of dormers visible in the street scene, I am satisfied that the proposal would not appear incongruous, poorly designed or overly-large.

Irrespective of the above, by reason of the proposed front dormers, the proposal would be contrary to criterion E)i) of Policy DMHD 1 of the LPP2. Nevertheless, the appeal property already features a front dormer which is material to my consideration of the proposal. While the proposal would replace the existing dormer with larger dormers, thereby increasing the bulk and massing at roof level, the proposed dormers would relate well to and integrate with the existing roof form. A substantial element of the original roof slope would be retained above the eaves line. In this context, the property would not appear top-heavy or incongruous.

Moreover, there would be limited visibility of the proposed development from [address] due to the siting of the appeal property at the northern extent of the street and the screening provided by the existing built form of the appeal property and the adjoining No 54, most notably the front gable. Consequently, there would be no adverse cumulative impact on the character, appearance or quality of the existing street or wider area. As such, whilst not entirely in accordance with criterion E)i), I consider that the proposal accords with Policy DMHD 1 of the LPP2 when read as a whole.

The Council suggests that other extensions in the surrounding area have been better designed so as to ensure a sense of balance with neighbouring properties and avoid significant distractions from the existing character of the area. Nonetheless, as I have reasoned above, I do not consider that the appeal proposal would be harmful to the character of the area. Therefore, the design of other extensions in the surrounding area does not, ultimately, lead me to an alternative

Accordingly, I conclude that the proposed development would not have a harmful effect on the character and appearance of the host building and surrounding area. In this regard, while there would be conflict with some of the criteria set out in Policy DMHD1 of the LPP2, the proposal would accord with the policy when read as a whole. It would also accord with the relevant provisions of Policy BE1 of the Hillingdon Local Plan: Part 1 – [name] (adopted 2012), Policy DMHB 11 of the LPP2 and Policy D3 of the London Plan 2021. Among other things, these policies seek development which harmonises with the local context and is well integrated with the surrounding area.

Representations from local residents comment on the planning history of the site, as well as other land in the ownership of the appellant, and raise concerns about the potential for the property to be converted into a House in [name]. However, I am assessing the proposal before me, my assessment of which has not identified any harm as I have reasoned above.

Notwithstanding the concerns of local residents regarding the effect of the proposal on parking on [address], I am satisfied that the proposal to convert a studio flat into a 2-bedroom flat is unlikely to significantly increase the demand for parking. Indeed, I have no reason to disagree with the Council’s conclusion that the development would have no net impact on parking demand. I note the Council’s comments in respect of the proposed layout of the parking. However, there is no substantive evidence before me to demonstrate that the proposal would have a harmful effect on highway safety. The provision of an extended dropped kerb would be a matter between the Council and the appellant. Ultimately, these matters do not lead me to an alternative conclusion on the main issue.

I have considered the Council’s suggested conditions against the tests set out in the National Planning Policy Framework. Where necessary, I have amended the wording of conditions for clarity, and to ensure compliance with the tests of both precision and enforceability.

In addition to requiring commencement within the relevant statutory period, I have imposed a condition requiring adherence to the approved plans. These conditions are imposed for certainty. The condition requiring adherence to the approved plans is also necessary in the interests of safeguarding the character and appearance of the property.

A condition relating to cycle storage is necessary in the interests of ensuring that appropriate facilities are provided to support sustainable forms of transport.

For the reasons given above, the proposed development would comply with the development plan and the material considerations do not indicate that the appeal should be decided other than in accordance with it. Therefore, the appeal should be allowed.