Appeal 3320330

The appeal is dismissed.

The main issue in this case is the effect of the proposed development on the character and appearance of the host dwelling and wider streetscene.

No. [site address] (No.7) is a two-storey semi-detached dwelling located on the south-east side of [address]. It forms one of two pairs of semi-detached dwellings on this side of [address], with the wider surrounding area predominantly comprising short rows of terraced properties.

To the side of No.7, is a driveway and a narrow two-storey flat roofed wing set well back from the front elevation. It is proposed to demolish this existing wing and extend over two-storeys to the side, projecting around 3.8m from the existing flank elevation. A porch is proposed to be constructed to the front of No.7, projecting the building line of the dwelling by around 1m over the existing. The two-storey side extension would, however, continue the existing front elevation of the main house, so without any set back.

The Chorley Householder Design Guidance Supplementary Planning Document (January 2017) (SPD) advises that it is important that the design of an extension relates to the whole structure of which it is part, whether that is a simple dwelling, a pair of semi-detached or a group of dwellings. In this case, the proposed two-storey extension has been designed such that both the eaves and ridge of the roof (including the original roof) would be raised by around 0.5m, to accommodate a large games room and storage area in the roofspace. [name] acknowledge that the accommodation provided would meet the needs of the occupants, and aims to make effective use of space, the resulting eaves and ridge would sit well above those of the attached neighbour. I find the height difference would appear incongruous in the context of this neighbour, failing to relate well to the structure of which it is part, and unbalancing the semi-detached pair.

Moreover, the combination of the lack of set back from the front elevation and roof height, means that the extension would fail to represent a subservient addition to the host dwelling. It would therefore be further contrary to the guidance in the SPD that side extensions should be subservient to the original buildings, set back no less than 1m from the existing main elevation and 1m lower than the main roof ridge.

I recognise that there are examples of differing ridge heights within groups of dwellings in the surrounding area, notably the terrace of dwellings diagonally opposite No.7. These examples, however, typically form part of a well-conceived composition and design of dwellings that reflects the variations in ground levels. [address] rises from its junction with [address], I do not find the level differences to be sufficient to warrant the proposed increase in roof height, rather it would break the roofline of dwellings on its south-east side appearing unduly prominent above its attached neighbour and within the streetscene.

The appellant has drawn my attention to an appeal decision at No.[address], Adlington [postcode] (APP/D2320/D/14/2221003). I do not have the full details of this appeal proposal before me, but I note that it pre-dates Chorley’s current SPD guidance and the proposal did not increase the ridge and eaves height of the host dwelling over the existing. That said, I agree with the Inspector in that case that SPD guidance should not be applied prescriptively and a pragmatic approach should be taken which responds to individual site characteristics. For the reasons already given, I find the proposal would fail to read as subordinate to the host dwelling and would appear visually incongruous in the context of the semi-detached pair. It is not therefore comparable to the appeal decision to which the appellant refers.

The proposed dormer would all but fill the rear roof plane No.7 and although set in slightly from the flank elevation it would not be offset from the ridge or eaves of the new roof. It would therefore conflict with the SPD guidance that rear dormers should cumulatively occupy less than 2/3rds of the width of the roof and should be set below the ridge, subordinate to the main roof structure. In combination with the increase in roof height, the proposed dormer would appear overly dominant. The building line of No.7 is set forward of the terrace of dwellings at No.9 to [address] and there is a reasonable separation distance between No.7 and No.9. Because of this, the flank elevation of No.7 is already prominent in the streetscene, when viewed from the north-east, and the proportions of the proposed dormer (and the its position on the new roof) mean it would be a very visible and unsympathetic addition.

I therefore conclude on the main issue that the proposals would cause significant harm to the character and appearance of the host dwelling and wider streetscene. In addition to the conflict with the SPD guidance, the proposals would conflict with policies HS5 and BNE1 of the Chorley Local Plan 2021-2026 (2015) because they fail to respect the existing dwelling and would have a significantly detrimental impact on the surrounding area by virtue of the height, scale, massing and design. It would also fail to reflect the principles of achieving well-designed places set out in Section 12 of the National Planning Policy Framework.

For the reasons given above, I conclude that the appeal should be dismissed.