Basement Flat, 3 Cavendish Crescent, Lansdown, Bath
3 Cavendish Crescent forms part of a Grade II early 19th century crescent terrace of terraced townhouses designed by John Pinch the Elder, some of which have since been subdivided into apartments, situated within the Bath conservation area and World Heritage Site. Externally, the crescent retains its grandiose, uniform appearance with rusticated doorway surrounds, multi-pane fanlight fenestration, first floor wrought iron balconettes, and raised stone surrounds around the first floor windows. As part of the original design, each townhouse retains a lower ground basement floor with vaults beneath the raised pavement, accessible via the front lightwell (although in some places the external staircase has since been removed). As a monumental residential set piece, it forms part of the Georgian Architecture and Town Planning OUV of the World Heritage Site.
8 Cavendish Crescent forms part of a terraced crescent of Grade II early 19th century terraced townhouses situated within the Bath conservation area and World Heritage Site. The raised pavement and railings to the front of the crescent are individually Grade II listed.
Whilst BPT does not typically comment on internal changes, we are concerned by the nature of the works proposed and the impact this will have on both the character of the basement and the health of the wider building as a whole.
Primarily, we have concerns regarding the proposed “tanking” of Vaults 1 & 2 without specification of the proposed tanking method. We strongly oppose the use of chemical injection or cementitious tanking within historic buildings. These impermeable materials do not allow the permeable traditional building fabric to breath or moisture to pass through; thus, moisture is displaced or trapped and frequently this can lead to problems elsewhere. In addition, these approaches have a short life span and are known to fail over the passage of time, but can result in irreversible damage to historic fabric when removed.
The reference to the tanking of the basement flat at 5 Cavendish Crescent is inappropriate; the existing cementitious tanking is an unauthorised intervention which cannot be used as a precedent, and the proposed cavity membrane system as part of application 19/00451/LBA was omitted from the granted consent.
We highlight that the proposed use of the vaults has not been specified as part of works; due to the dark, frowsty conditions of Bath’s historic vaults and basements, they are not generally suitable for domestic or residential use, such as additional bedrooms, etc., and would place these distinctive historic spaces under increased pressure for more invasive alteration works. We continue to strongly recommend the use of vaults for strictly ancillary uses, such as storage, for which they were historically intended.
Should the principle of damp proofing be found appropriate on this site, we suggest that more easily reversible means of damp proofing or management are specified such as dry lining and membrane lining systems, provided that internal features of interest would not be compromised. We maintain that the application in its current form does not provide an adequate level of detail against which the proposed impact to a Grade II building can be assessed.