Proposal
Erection of two single-storey rear extensions at ground and lower ground floor level following removal of existing shed; Installation of solar thermal panel on roof, thermal store and heat pump…
Our Response

11 Lambridge Place forms part of a Grade II 1792-1800 terrace of townhouses, situated within the Bath conservation area and World Heritage Site. It is situated immediately adjacent to the Grade II terrace at 17-29 Lambridge Place with which it forms part of a contemporaneous, albeit architecturally varied, group. The majority of the terrace has since been painted, with several dwellings having reverted back to a plain Bath stone ashlar façade.

BPT is supportive of the proposed removal of paint to ensure that the historic stonework is able to ‘breathe’. It is likely that further repointing and/or repair works may be necessary once the paint is removed which should be appropriately detailed via condition.

We note that no design reference or justification is provided for the insertion of Crittall doors within this context, which may be of some limited visibility from Upper Lambridge Street.

In the light of the declared Climate Emergency, BPT is generally supportive of retrofit measures that protect elements that contribute to the special architectural and historic interest of a listed building; alterations are expected to be visually coherent with the special interest of the building and the wider character and appearance of the conservation area.

We are supportive of the principle of secondary glazing to improve the thermal performance of the building without compromising its historic features or any retained historic glazing. The proposed extent of installation across the entirety of the front and rear elevation would ensure that any visual impact to the appearance of the windows would be consistent. The use of secondary glazing is typically a lighter touch and consequently reversible measure with minimal intrusion to the retained windows.

However, we note that there is no further detail provided regarding the proposed appearance of the secondary glazing, how this would interact with the existing windows, or means of fixture. We strongly recommend that appropriately detailed sections are provided to illustrate aspects such as how the secondary glazing would be fitted and the proposed frame profile and thickness. Where possible, we encourage secondary glazing frames to sit in line with the main window frames to obscure them from external view. Similar details should also be provided for the proposed “seasonal” glazing.

We are interested to see the proposed use of 13mm aerogel internal insulation in the study at first floor level, which could form the basis of a significant case study as to how internal insulation may be incorporated sympathetically within traditional and listed buildings. Further details are recommended as to any possible internal features of interest as well as how the aerogel would interact with more complex areas such as the window reveals and surrounds.

We are supportive of the installation of PV panels on an inner roof slope where this would be of negligible visual impact to the special interest of a listed building. In this case, an “evacuated tube solar thermal” system would be installed within the concealed inner roof valley and would therefore be appropriately screened from public view. However, we note that this is an unusual solar system in Bath with little design precedent and as such strongly recommend that further specifications and material details are submitted as part of this application to clarify the appearance, and finish of the proposed system. We maintain a preference for the use of monochrome, non-reflective panels, ideally in a darker colour that would sit more recessively against the roof scope. We feel it would be helpful to further explore the design options of this particular system to ensure the most sympathetic option is selected.

Application Number: 22/02089/LBA
Application Date: 19/05/2022
Closing Date: 28/06/2022
Address: 11 Lambridge Place, Lambridge, Bath
Our Submission Status: Comment