1 Sion Hill Place, Lansdown, Bath

1 Sion Hill Place forms part of a Grade I mid-18th century terrace of townhouses by John Wood the Elder, situated within the Bath conservation area and World Heritage Site. 1 Sion Hill Place forms the original end to the terrace, with a bowed range mirrored at 9 Sion Hill Place, both of which frame the central pediment of the terrace façade. The terrace has retained its well-balanced, symmetrical appearance with a continuous rusticated ground floor, bracketed balconettes across the first floor, and the retention of traditional features such as Georgian-style multi pane sash windows. This balance has been somewhat offset by the 1930s addition of the Grade II* Summerhill on the far west end of the terrace adjoining 1 Sion Hill Place. The building forms part of the elegant terrace morphology indicative of Bath’s polite Georgian vernacular, and therefore contributes towards the Georgian Architecture and Town Planning OUV of the World Heritage Site.

We note consent was granted for the conversion of the building to provide five apartments in 2020 (see 19/04568/LBA).

We consider the proposed use as residential apartments to be appropriate, but emphasise the need for the historic plan form and layout of 1 Sion Hill Place as a single, grand-scale Georgian residence to be protected where possible to sustain the special architectural and historic significance of a Grade I building. There may be an opportunity in future to bring the building back into single residential use, and we therefore encourage the use of ‘light touch’, reversible internal divisions with consideration for future adaptability as well as minimal harm to historic fabric.

We are not opposed to alterations to non-historic fabric, such as the removal of 20th century partitions from the upper floor hallways and the insertion of a lift shaft in the 1930s rear extension.

We have some strong concerns regarding the proposed opening between the principal front and rear rooms on the ground floor. The opening would be significantly larger than previously consented and would result in a significant loss of historic fabric and harm to the original floor plan of the building without appropriate justification. We therefore strongly recommend that the opening is minimised in accordance with the previous consent to sustain the legibility of the building’s original plan form and associated special architectural interest.

Further details are required as to the increase of services and sub-partitions across the first, second, and third floors with likely resulting cumulative impact on the plan form and historic fabric and detailing of a listed building. We recommend minimising necessary alterations in accordance with the previous existing consent, and further assessment with regards to potential interaction of works with architectural details such as cornicing or plasterwork.

We strongly recommend that further details regarding the proposed waterproofing works are submitted as part of this application to ensure this is compatible with the natural properties of historic fabric.

As part of the 19/04568/LBA application, a roof terrace was previously proposed but was consequently omitted from the scheme and did not form part of the consent.

The Statement of Significance and Heritage notes that “part of the roof is already used as a roof terrace”; this does not appear to be identified on the existing roof plan, nor does this form part of a previous consent.

BPT is always concerned about the impact of visible roof terraces within the historic townscape, as there is a risk of setting a precedent of altering Bath’s roofscape resulting in detriment to the established character. Proposals are assessed on a case-by-case basis, considering factors such as harm to visual amenity, increased perceived activity within roofscape views and resulting detriment to the character of the area, alterations to historic fabric, and residential amenity.

Whilst we acknowledge that the terrace would not be of high visibility, we feel it would introduce a new, inappropriate roof typology at odds with the established historic character and formalised appearance of a Grade I terrace and would not preserve or enhance the character or appearance of the conservation area. We are concerned that this would establish an unwelcome precedent for other similar terraces across the terrace with resulting cumulative harm to the historic roofscape.

Whilst we acknowledge that the two hipped roofs proposed for demolition are post-1930s and therefore would not constitute historic fabric, they are indicative of the traditional hipped roof form observed across both the existing historic roofscape of 1 Sion Hill Place, and the wider terrace. Therefore, the 1930s hipped roofs do contribute positively to the harmonious roof form, profile, and aesthetic, and consequently the group value of a Grade I terrace and their roofscape contribution to the vernacular of the wider conservation area. Consequently the proposed roof terrace would be considered to be detrimental to sustaining the homogenous appearance of the terrace; we further highlight the lack of material or design details for the proposed appearance or finish of the terrace.

There is already an existing “private shared garden” attached to the property for use by future residents which will address the need for appropriate outdoor amenity space. We therefore do not consider that the need for the proposed roof terrace is adequately justified, and as a private amenity space would not constitute a public benefit.

Therefore the proposed roof terrace would constitute less than substantial harm to a Grade I building with no public benefit, and would not preserve or enhance the character or appearance of the conservation area, and would be contrary to the Planning (Listed Buildings and Conservation Areas) Act 1990, Section 16 of the NPPF, and Policies B1, BD1, B4, CP6, D1, D2, D3, and HE1 of the Core Strategy and Placemaking Plan. We strongly recommend that the roof terrace is omitted from this application.