Appeal 6004211

The appeal is dismissed.

The original description of development is provided in a more succinct form in the decision notice. Therefore, the above description reflects this amended description.

The main issue is the effect of the proposal on the character and appearance of the host dwelling and the surrounding area.

The appeal property is a two storey semi-detached dwelling in a residential road of similar properties. The surrounding area is residential in character.

The Council indicates that the hip to gable conversion of the existing roof and the addition of a rear dormer and front rooflights are acceptable elements of the overall proposal. I agree given that similar alterations and additions have been made to a number of properties in the surrounding area and are, therefore, characteristic features. Consequently, the principal consideration in the context of the main issue is the effect of the proposed side extension in combination with the other proposed changes.

Policy CS1 of the [name] (2012) (CS) and Policy DM1 of the Harrow Development Management Policies Local Plan (2013) (DMP) require high standards of design and seek to protect local character. These requirements are also reflected in Policy D3 of the London Plan (2021).

The Residential Design Guide Supplementary Planning Document (SPD) says that where the property has already been extended by the conversion of a hipped to a gabled roof, a further side extension (first floor or two storey) is inappropriate1. Moreover, for side extensions a hipped rather than a gabled roof is preferable to reduce roof bulk2.

The side extension would be of proportionate width to the dwelling’s original frontage and would include matching windows. As such, based on these elements the extension would integrate effectively with the host dwelling. However, the extended roof would comprise stepped gables, which would add considerable bulk to the roof profile, contrary to the guidance in the SPD.

Furthermore, there are a number of examples of hip to gable conversions on nearby dwellings as the appellant contends, but there are no visible examples of the type of stepped gable arrangement resulting from the proposed changes to the original roof and addition of a side extension. Consequently, due to its prominence in the street scene, the extensions would result in visual harm to the host dwelling due to the bulky roof profile; and would be incongruous and uncharacteristic in the wider setting.

I acknowledge that the proposed extensions are intended to create additional living space in a sustainable location. However, this is not sufficient reason to overcome the harm and conflict with development plan policies that I have found would result from the proposal.

Accordingly, for these reasons, I conclude that the proposal would have a materially harmful effect on the character and appearance of the host dwelling and the surrounding area. As such, it is contrary to Policy CS1 of the CS, Policy DM1 of the DMP and to Policy D3 of the London Plan, as described.

I have had regard to the representation made by an interested party. This does not, however, raise any additional matters in relation to the main issue that would lead me to reach a different overall conclusion.

For the reasons given, the appeal should not succeed.