Appeal 3359905

The appeal is dismissed.

The National Planning Policy Framework was revised in December 2024 and amended on 7 February 2025 to correct cross references from footnotes 7 and 8, and to amend the end of the first sentence of paragraph 155 to make its intent clear. The 2025 Framework (the Framework) has not materially changed in terms of the identified main issues below and therefore, it has not been necessary for me to seek comments from the main parties.

The appellant describes the proposed development as a ‘double storey side and rear extension. Free standing building at the bottom of the garden to create a yoga room and home office’. The local planning authority (LPA) describes it as a ‘part two storey, part single storey side and rear extension including parapet wall, hip to gable roof extension with rear dormer over proposed first floor. Erection of detached garden room to rear’. I have used the latter in the banner heading as it more fully describes the proposed development.

The LPA does not object individually, as opposed to their collective impact, to the single storey rear elevation, the dormer, the detached garden room, or to any impact upon neighbours in terms of a loss of privacy or light. I have no reason to disagree to these elements when considered individually.

The main issues are the effect of the proposed development overall upon the design of the host property and the character and appearance of the area, and (ii) the effect upon the living conditions of the occupiers of No.[address] in terms of outlook.

The appeal property is a two-storey, 1930’s semi-detached dwelling located in a residential area of similarly designed houses, with a hipped roof and a double height bay with a double pitched roof to the front elevation. Like other properties in the immediate area, it is constructed in red brick and render, and it is set back from the road. It has a relatively narrow side area and a long rear garden.

These features and those of the adjoining properties add distinctively and positively to the character and appearance of the area.

The proposed development to the host property itself would include the replacement of the hipped roof by a straight gable, and the addition of a two-storey side extension which would wrap around the whole of the rear elevation. There would also be a further single storey addition beyond it, extending the length of the existing rear elevation. In addition, the rear elevation would also include a dormer to replace the existing rear roof, which would also extend along the whole rear elevation with its proposed gable. It would face the rear garden.

The extensions would have flat roofs. The visual effect to the rear of the property would be that of a stepped appearance, including the proposed dormer, the two-storey element and the single storey part.

The development would have a height greater than the eaves of the host property, The submitted plans would appear to indicate that the proposed development, including a parapet, would exceed the ridge of the host property, though this is denied by the appellant.

Even if this were not to be the case, I find that by their size, height, extent and design, the extensions, including their flat roofs, would appear as incongruous additions to the host property, not subservient but out of proportion to it, and would significantly and unacceptably detract from its appearance,

I consider that, while there are properties in the immediate area with gables, in the context of the appearance of the two semi-detached dwellings when seen together, the proposed change from a hipped roof to a gable would adversely affect the overall balance and symmetry of the semi-detached dwellings, even though the roof design of the other half of the pair of dwellings does not exactly match that of the existing roof of the appeal property, and even though I was able to note on my site visit that there are other semi-detached houses in the area, one with a hip and the other with a straight gable. However, I do not consider that their unbalanced effect is satisfactory or that this provides a template to be followed with regard to

[name] accept that there is a variety of external construction materials in the immediate area, the common use of brick and render adds positively to its character and appearance. I do not consider that the proposed use of a composite cladding material would assimilate well, though I accept that this might have been a matter which could have been controlled by condition had I been minded to allow the appeal.

When considered overall, the proposed development does not constitute good design. This is a matter to which I give very significant weight in the decision-making process.

Therefore, I conclude that the proposed development, when considered overall, does not accord with policies 55, 58 and 59 of the Cambridge Local Plan (2018) (LP) which require that development, including alterations and extensions, shall be sympathetic to the character of their surrounding areas and their related buildings. For the same reason, it would not accord with chapter 12 of the Framework.

Both parties refer to the 45 degree ‘rule’ drawn from the centre of windows in the adjoining property at No. [address] and where an extension beyond such a line might be considered to adversely affect the outlook from the adjoining property.

The appellant has produced plans to indicate the proposed impact in the above terms from the point of view of daylight and sunlight, though they also help to illustrate the impact in terms of harm to outlook. The plans indicate the position for a first-floor extension of 2.5 metres, differing from the extension claimed by the LPA of 4.0 metres.

The submitted plans indicate that the proposed extension at first floor level would have a distance greater than the 45-degree line from the centre of a window to the adjoining property, and that the same would apply regarding the proposed dormer. However, the margins are minor, such that the LPA does not contest that the effect upon lighting to the adjoining property would be insignificant. I consider that the same would be the case regarding any overbearing impact.

Therefore, while there may be some minor divergence from the 45 degree ‘rule’ referred to by the parties, I conclude that the proposed development would accord with policy 58 of the LP which requires that development does not unacceptably visually dominate neighbouring properties.

I acknowledge that the proposed development would help to meet the accommodation needs of the appellant and family, and also that the inclusion of what the appellant describes as a ‘solar array’ would help, in a small way, to meet the Government’s net zero target. Equally in minor ways, the inclusion of green roofs might enhance biodiversity, and the use of reclaimed brick would help to minimize construction waste. While the development would lead to more intensive use of the site, I am not convinced that this equates to its more efficient use.

However, these matters, neither individually nor collectively, alter or outweigh my conclusion in terms of design, character and appearance.

[name] have found that the proposed development would not have a materially harmful impact upon the living conditions of the occupants of No.[address] in respect of outlook, I have found that the design of the proposed development would have a very significant adverse impact upon the character and appearance of the host property and the area. This is a matter of overriding concern and is not outweighed by other considerations.

There are no material planning considerations that indicate the application should be determined other than in accordance with the development plan for the area and national planning policy. Therefore, for the above reasons, I conclude that the appeal should be dismissed.