Appeal 3325950

The appeal is allowed, and planning permission is granted for single storey side/rear extension, proposed loft conversion, including 1 no. rear facing dormer window 1 no. front facing dormer window at [site address] , [site address] , Buckinghamshire, [postcode] in accordance with the terms of the application ref: 23/05674/FUL dated 9 March 2023 subject to the following conditions:

The development hereby permitted shall be commenced before the expiration of three years from the date of this permission;

The development hereby permitted shall be carried out in accordance with the following approved plans: drawing no. 52 (location plan and proposed block/site plan), drawing 50 A (proposed plans) and drawing 51 A (proposed elevations);

Notwithstanding any indication of materials which may have been given in the application details of the zinc cladding, to be utilised within the dormer windows, shall be submitted to and approved in writing by the Local Planning Authority prior to installation on site. The development shall be maintained in accordance with those approved details;

Prior to occupation of the development hereby approved two bat or bird boxes shall be attached to the dwelling, in a position suitable for their intended purpose, and maintained and retained for the lifetime of the development.

Since the determination of the application, and the submission of this appeal, a revised National Planning Policy Framework 2023 (the Framework) was adopted on 5 September 2023. Despite this the refusal reason does not reference the Framework so this is not considered to impact upon the determination of this appeal.

There are several elements to the appeal proposal. The refusal reason is specific in its reference to the dormer extensions with the Council’s delegated report confirming that there is no objection to the single storey extension. I have no evidence before me to conclude differently on that element and in that regard this appeal will focus upon the proposed dormer extensions in the context of the main issue outlined below.

The main issue is the impact of the proposal upon character and appearance of the host dwelling and character of the area.

The appeal site is a detached residential dwelling located in a primarily residential area off [address]. Access to the site is shared with neighbouring property (no.39) with parking to the front and a garden area contained to the rear of the dwelling. At the time of my site visit I found that the appeal site is situated in a location which is varied in terms of character with surrounding dwellings being a mixture of detached, semi-detached, and terraced two storey dwellings which are of varying age, style, and design.

I note that as part of the original permission, that a condition was applied removing permitted development rights for extensions, roof alterations and outbuildings. Such a condition does not seek to prevent all future development but is rather designed to allow the Council to consider, and allow, only appropriate development based upon an assessment as to the surrounding character and appearance at the point an application is made. In considering whether a proposal is of generally appropriate scale - a rear dormer window of the proposed bulk, scale, and form (albeit with facing materials as similar appearance to the main dwelling) would likely be within the scope allowed for under permitted development rights (had they not been controlled by condition).

The proposed rear dormer window would be set in from the flank eaves line and I find that the original roof form would be fully legible. The overall dormer would not dominate, or overwhelm, the rear roof slope and I do not find that it would appear boxy or top heavy when viewed within the context of the rear roof slope. In terms of the host dwelling itself, I find that the proposal would be of appropriate design which respects both the character and appearance of the existing property at the rear elevation. At the time of my site visit I also walked up, and down, [address] and found that the rear dormer window would be of limited visibility in the public domain albeit I acknowledge that there may be some, limited, views from the north at an angle when stood outside of no. 37 which is set back when compared to the appeal site.

The Council’s delegated report discusses the Householder Planning and Design Guidance Supplementary Planning Document 2020 (SPD) which is, ultimately, guidance and not policy. The objective of the guidance surrounding roof extensions and alterations is to avoid serious impact on the appearance of a dwelling due to the roof being a highly visible part of a building. I find that the proposal is generally consistent with the design specifics set out in 11.3 and whilst it would be contrary to some design guidance, such as being set below the ridge line, I find that the dormer has been kept as small as is reasonably possible and would add a contemporary feature to a building which is, compared to the surrounding dwellings, a comparatively modern building of currently limited architectural design.

The proposed front dormer would utilise a flat roof and abut the ridge of the dwelling with limited set down. Despite this it is evident, from the plans, that the overall size of the dormer proposed at the front of the dwelling is limited and is not substantially larger than the window it is designed to contain. As a result of this, I find that this minimises the impact that the dormer has on the shape of the roof and achieves appropriate proportions as well as sitting behind the most imposing feature of the existing dwelling which is the two-storey front projection of the building. Furthermore, the proposed window, within the dormer, is smaller than those at ground and first floor level meaning that the proposal suitably complements the more modern age of the host dwelling as well as ensuring that the addition is subservient within the front roof slope.

Whilst the Council’s delegated report states that the proposal is contrary to the SPD, due to the use of a flat roof, I find that the guidance does not specifically outline a blanket resistance to the use of flat roofs. The design guidance simply outlines that flat roofs will not normally be acceptable, however, an exception to this could be in contemporary design. Overall, the design, and use of materials, would result in a contemporary design which I find is consistent with the overarching objectives of the SPD as an appropriate, subservient, addition to the host dwelling which would not have a detrimental impact and would ultimately be an ancillary addition to the existing dwelling.

The Council’s refusal reason states that the roof extension would be visually intrusive in the public realm and within the appearance of the site which would erode the established pattern and character of the area. As previously stated, in relation to the rear dormer, I find that this would be limited in views within the general appearance of the site. The Council’s delegated report fails to provide any evidence of assessment as to the stated established pattern and character of the area in coming to the conclusion that the dormers would be harmful to the character and appearance of the surrounding area.

At the time of my site visit I did not find there was any particular uniformity or consistency to existing built development and found the general type, and design, of residential development in the vicinity to be mixed. [name] did not see evidence of front dormer windows being a notable characteristic, I do not find that this would warrant refusal for what is, ultimately, a small dormer window which would appear subservient and viewed behind the two-storey front projection which would retain its prominence within the street scene. The front dormer would not appear as a dominant or intrusive feature from the south. Views of the front dormer, from the north, would be obscured by the existing two storey front projection again limiting the visual impact of the proposal to the front roof slope.

The proposal would be consistent with Wycombe District Local Plan 2019 (LP) Policy CP9 which requires development to achieve a high quality design, LP Policy DM35 which requires proposals to demonstrate attractive and high quality design and appropriate character in the scale, form, layout and detailed design of buildings and LP Policy DM36 which requires development to respect the character and appearance of the existing property, be subservient in scale and ancillary and function to the existing dwelling and respect the character and appearance of the surrounding area. The proposal would also be consistent with the guidance contained within the SPD insofar as the guidance seeks to avoid serious impact on the appearance of a dwelling due to the roof being a highly visible part of a building.

I note third party comments raising concerns as to the proposals. The Council raise no reason for refusal based upon residential amenity, with regard to privacy, and I have no evidence to conclude differently based upon the plans and what I saw at the time of my site visit.

The proposed dormer window would introduce windows within the roof slope of the dwelling which currently do not exist, however, given the relationship between the appeal site and the neighbouring property at [address], I find it is unlikely that it would result in direct views towards the neighbouring dwelling to a degree which would warrant a justifiable reason for refusal. Views which would be available from the proposal would, at most, be oblique and facing deepest points of the neighbouring garden where an existing degree of mutual overlooking is generally expected in an area with such density and layout of development.

I also note that concern is raised as to the utilisation of zinc as an external finish within the proposals. Zinc is a relatively commonly used type of metal cladding and I have no evidence before me to suggest that utilisation of such material would cause reflection which would be to the detriment of neighbouring properties as the morning sun rises from the garden. In any case a condition, requiring approval of the dormer cladding, can be applied to any permission granted to ensure an appropriate finish prior to installation on site.

A time condition is attached to comply with Section 51 of the Planning and Compulsory Purchase Act 2004. A condition requiring the development to be in accordance with the approved plans is required to control and define development which is granted consent. The Council have also suggested a further condition relating to biodiversity and ecological features and a condition is applied relating to bird or bat boxes to increase biodiversity opportunities in accordance with requirements set out in the Local Plan which I find reasonable to apply.

The Council have suggested a requirement for submission of a schedule/sample of materials and finishes for the development. The application form confirms that for the extension the materials are to match the existing dwelling – this does not require further information. The dormers are stated to be zinc external wall finish with dark grey single ply roofing membrane. I have applied the condition requiring submission of a schedule/sample of materials for the dormer windows only given that zinc cladding can, ultimately, be supplied in a number of pre-weathered or pigmented finishes. The final choice of material would, therefore, benefit from approval via condition to ensure an appropriate finish. This condition does not need to be timed according to work above damp-proof course but is more appropriately required prior to installation which would allow work to commence on the single storey extension but still ensure appropriate materials were agreed prior to installation on the dormers.

For the reasons outlined above, and taking account all other matters raised, I conclude that the appeal should be allowed subject to conditions.