Basement, 28 Grosvenor Place, Lambridge
28 Grosvenor Place forms part of a Grade I late Georgian terrace situated in the Bath conservation area and World Heritage site. The basement vaults beneath the pavement are included within the designation, and contribute strongly to the architectural and historic significance of the terrace due to their distinctive barrel shape and frowsty character, as well as providing some evidential insight into how each terraced dwelling would have functioned and been inhabited.
Whilst the Trust is not supportive of the conversion of vaults into inhabited spaces, we appreciate that the basement of 28 Grosvenor Place has already been adapted into an apartment. Therefore, we do not oppose the installation of a new waterproof system, although we have some concerns regarding the lack of information regarding the proposed membrane system, and we remain unsupportive of works that have gone ahead without the necessary listed building consent having been acquired first. The D&A Statement notes the fitting of a waterproof lining, but there is little elaboration regarding how any moisture will be channelled and drained out from behind the lining. We would emphasise that the potential for moisture to be trapped behind a waterproof lining without necessary ventilation or draining can exacerbate any existing damp problems.
Furthermore, we feel that leaving the existing cementitious slurry in situ will cause further harm to historic fabric by blocking the permeability of the outer walls of the vault and continuing to trap and displace moisture. Therefore, whilst we appreciate the reluctance to remove the remaining cement due to possible harm to historic fabric, we feel that the potential for continuous, ongoing harm caused by leaving it in place would justify its removal. We trust that officers will ensure the appropriate approach to these vaults.