Appeal 6000023

The appeal is dismissed.

On 12 December 2024 the Government published its revised National Planning Policy Framework (Framework). Its content relative to the main issue of the appeal is largely unchanged. It has not therefore been necessary to give the parties opportunity to comment on the revisions.

Whether the proposal would preserve or enhance the character or appearance of the Progress Estate Conservation Area (PECA).

The appeal dwelling is within the PECA. Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 (LBCA) requires special attention to be paid to the desirability of preserving or enhancing the character or appearance of a conservation area.

The PECA is a unique residential estate, that was built in a single phase over a short period of time. The area has a strong sense of place. Almost all the original buildings are retained. They are generally arranged in simple terraces, with a variety of unpretentious features that are usually repeated across a terrace or group, to create an interesting and picturesque streetscene. Façades are ordered, and most terraces are symmetrical, yet subtle variations in terms of design and siting give the impression that the area developed gradually. These characteristics contribute to the area’s special architectural and historic interest.

The appeal dwelling is at one end of a terrace. It has a plain roof slope to the front and rear, and a gable end to the side. The terrace includes two dwellings that are perpendicular to the others to create forward and rearward facing gables. These stand to either side of the central two dwellings and overall create a strong sense of symmetry across the terrace. This is most readily appreciated at the front where the terrace fronts the road and is centred on another symmetrical terrace on the opposite side.

Additionally, its strong massing and overall form is discernible across its rear façade, where it can be viewed with ease in its entirety across the rear gardens and from the dwellings opposite. The terrace is without rearward extensions above the ground floor. It has a strong and striking form at the rear, that includes the symmetrically placed gables and a regular pattern of chimneys. The rear face is made more dominant from the rear gardens as they slope away to the west. For these reasons the terrace is an important positive contributor to the character and appearance of the PECA.

The rear of the terrace is however not easily viewed from the public domain and the Progress Estate Conservation Area Character Appraisal primarily refers to areas of public realm. However, conservation area designations cover whole areas. Whilst rear or secondary spaces will usually be less important in defining the character or appearance of an area, they still often have significance and contribute to the overall integrity of an area; and this can certainly be said of the rear of the terrace of which the appeal dwelling is a component.

The proposal includes a first floor rear extension, to sit over the existing ground floor extension. This would break the unpunctuated rear façade of the terrace, and in doing so would harm its original form and appearance, and in particular its strong sense of order and symmetry. The hipped roof would further add to this harmful and intrusive impact, as prominent gables characterise the terrace.

The extension would otherwise have limited impact on the streetscene. Its set back from the side would retain the form of the gable end of the terrace, and its lower roof would give it a subservient form from this perspective. However, the harm to the original form of the terrace would be significant when viewed from the rear, for the reasons given. The level of harm would however be modest overall, as it would be limited in the context of the whole area of the PECA.

A recently erected side extension at No. [address] is referred to by the appellant. It differs significantly however, as it relates only to a pair of dwellings. It does not therefore cause me to reach a different conclusion on the acceptability of the proposal before me.

The proposal includes the replacement of the existing windows. The existing windows are badly detailed uPVC units; with casements that are unbalanced, sit proud of the frames, and with top opening fanlights and glazing bars that sit within the sealed glazing unit. As a result the existing windows appear wholly out of place in the context of the original casement pattern that prevails across the estate; an issue that is demonstrated well by comparing them with the well detailed timber windows of the neighbouring dwelling.

The proposed replacements would also be constructed in uPVC but would attempt to replicate the flush fitting and balanced design of the estate’s original windows. The submitted details are sufficient to demonstrate that they would achieve this aim, and the lack of clarity over the width of the proposed glazing bars could be clarified by the use of a condition if the appeal is allowed. The proposal does not include top hung openings, so it is unclear why the Council refers to this.

In terms of the Framework, the harm arising from the rear extension would be less than substantial, but would nevertheless be of considerable importance and weight. Paragraph 215 of the Framework establishes that any harm should be weighed against the public benefits of the proposal.

The benefits of the extension are private and associated with the current and potential future needs of the household. The proposal includes a loft conversion to which the Council does not object. This could be implemented without the rear extension, although the existing dwelling functions well as a small family home. I am therefore not satisfied that if the extension was not built the dwelling would cease to be viable.

A public benefit would arise from the replacement windows. Whilst the replacement units would be better detailed than the existing, the weight that I should give this benefit is limited by the ongoing use of uPVC, which is a modern material that has different characteristics to traditional timber.

Paragraph 212 of the Framework states that great weight should be given to the conservation of a heritage asset. The weight that I give to the benefit of the replacement windows would not be sufficient to outweigh the harm that would arise from the proposed extension.

In summary, the proposed extension would fail to meet the requirements of the LBCA as it would not preserve the character or appearance of the PECA. The proposal would not accord with Policies D3 and HC1 of the London Plan 2021, and Policies DH1, DH3, DH(a) and DH(h) of the Royal Greenwich Local Plan Core Strategy 2014. Together these seeks to ensure that development proposals should respond positively to local distinctiveness and conserve heritage assets.

For the reasons above, the appeal should be dismissed.