Parish Centre, 5 Harley Street, Lansdown, Bath
5 Harley Street forms part of a pair of Grade II early 19th century terraced houses, since converted to office and HMO use, situated within the Bath City-Wide Conservation Area and the World Heritage Site. The other half of the listed pair is No. 6; there is a discrepancy in articulation and finish between the two buildings which may be attributed to the insertion of the neighbouring parish hall in 1885. No. 5 is indicated to have been vacant for up to 10 years, which has exacerbated the poor condition of the building and deterioration of internal and external fabric.
It is indicated that planning permission was originally granted for the change of use and refurbishment of the building to provide “7no self-contained flats and separate offices” which has since lapsed (see 14/01153/FUL & 14/01154/LBA).
In principle, BPT is supportive of proposals to bring a vacant and deteriorating listed building back into use, where this would secure the ongoing occupancy of the property as well as associated benefits such as ongoing maintenance and repair.
We further welcome the provision of much-needed residential accommodation within the city centre where this would make a contribution towards local demand. Residential use would be in keeping with the general character of the local area. At this stage, we strongly encourage that the proposed flats would be made available for long-term lets for local residents and key workers, rather than being used as holiday lets.
Whilst BPT does not typically comment on internal works without the benefit of a site visit, we maintain a position on the use of waterproofing systems within listed buildings, and as such have heritage concerns regarding the proposed “fully-bonded structural ‘tanking’ works” at basement level. No further material specification has been provided. Whilst Cannon Clarke indicates that a “fully vapour permeable” system would be selected, from our experience fully-bonded systems are typically liquid-applied or cementitious which are applied as an impermeable layer over the surface of historic stonework, and are often very difficult to remove at a later date without resulting in damage to historic fabric. We therefore emphasise the importance of specifying the type of system proposed as part of this application rather than leaving it to Condition, to ensure the proposed intervention would be compatible with the natural qualities of Bath stone. Whilst it is indicated that some of the walls at basement level are completely saturated, it is unclear as to how much of this can be attributed to the existing gypsum plaster layer (which would be allowed to dry out once the gypsum is removed), and why this cannot be suitably managed by the cavity drain membrane system proposed at basement level.
We do, however, note the proposed use of an insulating lime plaster across the internal face of the walls which we consider to be a positive intervention, where this is compatible with the properties of Bath stone, is sympathetic to any retained internal features or detailing, and may help to reduce thermal loss through the walls.