Appeal 3320543

The appeal is dismissed.

As part of their appeal submission the appellant has submitted a revised drawing for plan number 1522/208-2, as this drawing submitted with the application only shows 2 front dormer windows and not the 3 proposed and shown on other submitted drawings. This is a minor correction and one that the council have raised no objection to. On this basis I am happy to accept the revised drawing1522/208-2A and have determined the appeal on that basis.

The main issues are the effect of the proposal on: • The character and appearance of the appeal dwelling, the terrace of which it forms part and that of the Crabtree Conservation Area (the CA); and, • The living conditions of neighbouring residential occupiers with reference to basement proximity to boundaries.

The appeal dwelling is an end of terrace two storey house with a gable end, a small front garden and narrow rear garden. To the front it has a two storey bay with an expressed gable feature above. The gable end of the appeal dwelling faces towards the rear garden of [address] (No.89/91).

It is located in an area of similar terraced houses and terraced maisonette pairs similar to No.89/91. The character and appearance of the local area is generally defined by these Victorian and Edwardian residential properties set out in a rectilinear street plan. This generates a coherent character defined by the consistency of design and architectural quality of these terraced properties, including the terrace of which the appeal dwelling forms part and which contributes to the significance of the CA within which the appeal dwelling sits.

The CA is a heritage asset to which I have a statutory duty under section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990. I must pay special attention to the desirability of preserving or enhancing the character or appearance of a Conservation Area.

The proposed front flat roofed mansard extension with three dormers would be tiled and would sit between an extended gable flank wall of the appeal dwelling and an extended party wall upstand that the appeal dwelling shares with the neighbouring terraced house. This would replace the existing front roof slope of the appeal dwelling.

The proposed mansard extension and dormers would sit in close proximity to the existing feature gable above the two storey bay at the front of appeal dwelling, and would alter the gable ended profile of the property that, given its adjacency to the rear garden of No.89/91, is a very visible aspect of the terrace of which it forms part and is characteristic of the street views of terraces within the CA.

Due to the scale and form of the proposed mansard extension, it would appear to dominate the appeal dwelling and would fail to appear as a subservient addition. The proposal would, therefore, fail to reflect the design, form and scale of the appeal dwelling and the terrace of which it forms part and would appear as a dominating and incongruous addition.

Further, due to the end of terrace and corner location of the appeal dwelling, the proposed front mansard extension would be prominent in the local streetscene. In street views, its dominating and incongruous appearance, in relation to the host dwelling and terrace of which it forms part, would be unduly apparent. This would detract from the townscape and streetscene of the local area and its existing coherent character.

In this regard, the proposal would also fail to reflect the contribution that the host dwelling, and the terrace of which it forms part, makes to the significance of the CA, and would fail to preserve or enhance the character or appearance of the CA.

I see no reason to demur from the council’s conclusion that the rest of the proposed extensions and alterations would have no significant effect on the character and appearance of the appeal dwelling or the significance of the CA.

[name] have considered the existing front roof mansard extensions to other properties in the terrace at 53 and [address], these are of some age and predate the designation of the CA. These evidently fail to reflect the original character and appearance of their host dwellings and the terrace of which they form part, thereby detracting from the coherent character of the local area and fail to make any contribution to the significance of the CA. Their existence does not justify the effect of the proposal on the appeal dwelling or the CA that I have identified above.

The appellant has also drawn my attention to other existing or proposed front mansard extensions in the local area, including a proposal for the mid terrace property at [address] that was allowed on appeal1. This was allowed on its own individual merits, where the approved proposal would have adjoined the existing mansard extension at No.55, and as a mid-terrace property the proposal would be significantly screened by neighbouring feature gables above 2 storey bays in many tangential local views.

As such, No.55 does not play such a significant role in the character and appearance of the local area as the appeal dwelling where its end of terrace location and concomitant gable end is recognised as a feature that contributes to the significance of the CA. The end of terrace location of the appeal dwelling would also result in less screening from neighbouring front feature gables, and the proposed front mansard to the appeal dwelling appearing unduly prominent when compared to that allowed an appeal at No.57.

Similarly, the front mansard allowed on appeal2 at [address] (No.75) brought to my attention by the appellant, would have been approved on its own merits. [name].[address] property and the allowed extension is similar to the appeal proposal, the local context and proximity of two storey properties that front [address], the flanks of which are set forward of the building line of the terraced properties in [address], result in this allowed proposal being less prominent than the appeal proposal.

The proposals in these recently allowed appeals would have been considered on their own individual merits and I have done likewise in my consideration of the appeal proposal. I have, therefore, given these moderate weight in my considerations.

Further, I find that the proposal would represent an additional roof level extension to a property in this part of the street, over that of existing or allowed. This would result in a cumulative effect from such developments that would detract from the coherent character defined by the consistency of design and architectural quality of these Victorian and Edwardian terraced properties, including the terrace of which the appeal dwelling forms part, and which contributes to the significance of the CA.

The proposed basement extension would extend across the full footprint of the appeal dwelling as extended above ground and would extend to create lightwells to the front and rear. The proposed rear basement and lightwell would, therefore require an excavation that would be the full width of the appeal property to the boundary with neighbouring properties. 1 Appeal Ref: APP/H5930/D/22/3303260 2 Appeal Ref: APP/H5390/D/20/3264471

Policy DC11 of the Hammersmith and Fulham Local Plan (2018) (the Local Plan) sets out that new basements will only be permitted where they are set back from neighbouring property boundaries, where it extends beyond the footprint of the building. The Council’s justification for this is to limit the impact of construction on local residents and to allow for sufficient margins to sustain growth of vegetation and trees. Both reasons directly relate to amenity and the living conditions of neighbouring residential occupiers.

As the proposed basement reaches to the boundary with neighbouring properties at the rear where it extends beyond the footprint of the appeal dwelling, the proposal fails to accord with this policy. Whilst the appellant has confirmed that the proposal extends to the boundary and not beyond it and would have 1 metre of soil above it, the appellant has not drawn my attention to any exceptional circumstances to justify non-compliance with this policy.

I find, therefore, that the proposal would not provide the required limit to the impact of construction of basements on local residents or to allow for sufficient margins to sustain growth of vegetation and trees. As such, the proposal would fail to protect the amenity and living conditions of neighbouring residential occupiers.

The appellant has proposed that I should consider a split decision should I find that only certain aspects of the proposed development would result in dismissal of this appeal. However, I find that the proposed development, whilst made up of many elements, is a fully integrated proposal. As such I do not find that making a split decision would be reasonable.

For the reasons given above, the proposal would result in significant harm to the character and appearance of the appeal dwelling and would fail to preserve or enhance the character or appearance of the CA. The proposal would also result in moderate harm to the living conditions of neighbouring residential occupiers.

This would not accord with the key principles CAG2, CAG3, CAG4 and BL2 of the Hammersmith and Fulham Planning Guidance Supplementary Planning Document (2018) and Policies DC1, DC4, DC8 and DC11 of the Local Plan Policy D3 and HC1 of the London Plan (2021) and Sections 12 and 16 of the National Planning Policy Framework (2021) (the Framework).

These collectively seek to ensure that development is of high quality design, having due regard to the importance of preserving or enhancing heritage assets and protecting the living conditions of neighbouring residential occupiers.

[name] find the harm to the CA that I have identified would be less than substantial, in accordance with the Framework, great weight should be given to the conservation of heritage assets. Whilst the proposal would result in a larger property with improved living conditions for its occupiers, these are substantially private benefits. I must give considerable importance and weight to the effect on the significance of the CA and substantial weight to the effects on the character and appearance of the appeal dwelling that I have identified and moderate weight to the harm I have identified to the living conditions of neighbouring residential occupiers. I consider that these benefits do not outweigh this harm.

The appeal is dismissed.