4 Prior Park Buildings, Widcombe, Bath

4 Prior Park Buildings forms part of a Grade II early 19th century terrace attributed to John Pinch, situated within the Bath conservation area and World Heritage Site. The terrace is predominantly 3 ½ storeys tall in Bath stone ashlar with a rusticated ground floor, set symmetrically around a central tympanum. However, it is well set back from the roadside and largely concealed from view from Prior Park Road by an elevated band of mature trees and is accessed via two side lanes at Forefield Rise and Prior Park Cottages.

Proposed Garage:

We note proposals for a double garage were originally granted consent in 2015 (see 15/05509/LBA). There are already a number of examples of two storey garage developments to the rear of the terrace that retain an appropriate single storey presence on the lane. We emphasise that this building should remain in an ancillary use connected with the main domestic function of 4 Prior Park Buildings, which should be a condition of any forthcoming consent.

Proposed Dormers:

The building as existing features a small single-bay dormer window of an unspecified age on both the front and rear roof slopes. These are currently small and recessive additions to the roofscape which, whilst they do not contribute to the special architectural interest of the listed building or its terraced context, do not significantly detract from its appearance and character. The terrace features a mix of dormer window and rooflight additions which results in a somewhat eclectic overall appearance, although existing examples of oversized full-width dormers are visually incongruous additions that should not be considered an appropriate precedent for replication on neighbouring buildings.

We therefore have some concerns regarding the proposed addition of an increased number of dormer windows of a larger height, scale, and massing across both roof slopes, and the resulting adverse impact to the appearance of a listed building and the character and appearance of the conservation area.

We note that there is arguably an opportunity for a new pair of dormers that better align with neighbouring examples as well as creating a symmetrical re-alignment with the fenestration of the main building body.

However, the single bay dormers as proposed appear to be much wider than neighbouring examples with an overly thick lead surround, resulting in a much visually heavier presence in the roofscape. The windows themselves also appear to be slightly wider than the windows below, at odds with the traditional Georgian ‘order of proportion’. The dormers would take their higher position on the roof slope from the later 20th century full-width dormers (see No. 3); we strongly recommend that these should be brought down in line with No. 5 to set these down behind the parapet and reduce the perceived height of the dormers.

We therefore conclude that these dormers as currently proposed would result in further harm to a listed building and the wider group value of the terrace, and should be omitted from the scheme.

Proposed Vacuum Double Glazing:

In light of the declared Climate Emergency, BPT is supportive of sensitive sustainability retrofits, where deemed appropriate, within the historic environment, as well as the sympathetic upgrade of traditional and listed housing stock to better meet modern standards of living.

The existing windows are indicated to be modern replacements, and are of a 1-over-1 fenestration style indicative of being a later addition to the building. These have superceded the multi-pane 6-over-6/6-over-9 fenestration which would have been original to the building’s design and construction. We therefore recognise that this is a positive opportunity to reinstate the building’s original historic fenestration and improve its thermal performance with NO loss of historic fabric.

There are very few examples of ultra-slim double glazing such as vacuum glazing being used in Bath. Similar schemes were recently granted planning consent at 12 Hanover Street and 13 Caroline Buildings, which remain the only comparable examples with regards to potential visual impact. There would be an exciting opportunity to trial this technology, with potential benefit for future window retrofit with an increased thermal performance and reduced visual impact.

The technical specifications of Fineo glazing includes reference to the use of “20 mm grid micro-pillars” between the individual glazing panes, which may result in the windows having a ‘speckled’ appearance and detract from the overall appearance of the listed building. We therefore maintain some concerns as to how this glazing would appear within the principal frontage of a listed building, and the wider grouped setting of the terrace. We maintain that there is a need for further assessment of visual impact as part of this application, potentially utilising a glazing sample or the installation of a ‘trial’ window with the support of the case officer. BPT would be very interested in engaging further with the applicant with the possibility of a site visit to see the proposed vacuum glazing in situ.

However, we regret that we are unable to support the use of applied glazing bars, rather than traditional through glazing bars, which would be an incongruous visual and material addition across the principal façade of a listed building. This would result in adverse impact to the established fenestration style and traditional construction not only of the building, but the integrity of the wider listed terrace. Examples of proposed multi-pane sash windows with vacuum glazing at Hanover Street and to the rear of the Circus indicate the use of through glazing bars, although this may necessitate glazing bars of a slightly increased thickness. As such, there remains some uncertainty as to the viability of through glazing bars when considered against other similar listed building proposals.

We recognise that there are identifiable public benefits in the installation of slim double glazing and the associated contribution this would make towards the adaptation of our historic building stock to meet the challenges of climate change, as well as their sustainable future use. However, we consider that this would be outweighed by the harm to the special architectural and historic interest of multiple listed buildings, and would not preserve or enhance the character or appearance of the conservation area.

Conclusion:

We maintain that this application would result in accumulated harm to a Grade II listed building and the wider grouped setting of the listed terrace and the character and appearance of the conservation area, contrary to the Planning (Listed Buildings and Conservation Areas) Act 1990, Section 16 of the NPPF, and Policies B1, D, D2, D3, and HE1 of the Core Strategy and Placemaking Plan. We therefore recommend that this application is refused or withdrawn.