Appeal 3359567

The appeal is dismissed insofar as it relates to the dormer extension.

The appeal is allowed and planning permission is granted insofar as it relates to the single storey side extension at [site address] , Roby, Knowsley [postcode] in accordance with the terms of the application, Ref 24/00547/FUL, dated 11 October 2024, and the plans submitted with it, so far as relevant to that part of the development hereby permitted and subject to the following conditions:

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The single storey side extension hereby permitted shall be carried out in accordance with drawing nos. A100 Site and [name], A103 [name] and A104 [name].

The external materials of the single storey side extension hereby permitted shall match those used in the existing dwelling.

The Council has only raised substantive concerns with regards to the proposed dormer extension and not in reference to the proposed single storey side extension. From the evidence before me, I see no reason to disagree with the Council’s position with respect to the single storey side extension. I am satisfied that the dormer extension is clearly severable from the single storey side extension, as it is physically and functionally independent. Therefore, under section 79(1)(b) of the Town and Country Planning Act 1990, I have the power to issue a split decision in this case.

The Government published a minor revision to the National Planning Policy Framework (the Framework) on 7 February 2025. Those parts of the Framework most relevant to this appeal have not been amended. As a result, I have not sought comments on the minor revision to the Framework, and I am satisfied that no party’s interests have been prejudiced by taking this approach.

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

The appeal property is a detached 2-storey house located within a large modern housing development. The estate contains different house types, of which the majority are 2-storey in height, with either gable end or hip end roof designs. The variety of the house types are complementary and there is consistency in terms of layout, scale, mass and form that contributes towards the consistent and pleasant character and appearance of this modern suburban area.

The appeal property has a gable end roof design, and the ridgeline runs perpendicular to [address]. The proposed alterations to the roof would take the form of a large flat roof dormer, occupying a significant proportion of the south facing roof slope. Consequently, the dormer would dominate and give a bulky, top-heavy feel to the southern roof slope, that would result in the house appearing unbalanced. This would harm the character and appearance of the existing house. Moreover, as the proposed dormer would be highly visible from [address] and neighbouring properties, it would also be detrimental to the character and appearance of the surrounding area.

I have considered the argument that there are other dormers in the locality of the appeal property. I observed that the front dormers to a limited number of properties that face a circular shaped landscaped feature on [address] were significantly smaller than the proposal before me. A similar dormer to that proposed is located on a house at the end of a nearby cul-de-sac, that is not readily visible from the street. Moreover, that dormer faces a wooded area along the boundary with a neighbouring site. As such, these other dormers are not directly comparable to the circumstances of the appeal site and the proposal, and they do not reduce the harm the proposal would cause or make it otherwise acceptable. I have considered the appeal before me on its individual merits.

For the above reasons, I conclude the dormer extension would have a harmful effect on the character and appearance of the host building and the surrounding area. As such, it would be contrary to Policies CS2 and CS19 of the Knowsley Local Plan Core Strategy and saved Policies H5 and H8 of the Knowsley Replacement Unitary Development Plan. These policies seek good quality design that responds to its surroundings, and extensions which are not disproportionate to the original dwelling. The proposal would also be contrary to the Council’s Householder Development Supplementary Planning Document, which states that dormers should not be so large as to dominate the roof slope resulting in a dwelling which appears unbalanced.

With regards to the proposed single storey side extension, and in addition to the standard time condition, I have imposed a condition requiring that the development is carried out in accordance with the approved plans, as this provides certainty. A condition is also necessary for materials to match those used on the existing house to protect the character and appearance of the area.

The appeal proposal includes two different elements. Having had regard to the development plan as a whole, the Framework and all other matters raised, I dismiss the appeal in respect of the dormer extension. However, I allow the appeal in respect of the single storey side extension.