Grosvenor Lodge, Grosvenor Place, Lambridge

Proposal
External alterations to replace roof covering with new natural slate and replace central clay tiles as required to incorporate additional insulation and breathable roof felt.
Our Response

Grosvenor Lodge is a Grade II early Victorian terraced house located within Bath’s conservation area and World Heritage site. It is situated along London Road, a historic route into the city centre featuring a high concentration of Grade II Georgian and early Victorian terraces, to which this property contributes a positive aesthetic and architectural significance. This application documents a recent history of poor maintenance that has now affected Grosvenor Lodge’s function and traditional appearance; therefore, this application will be considered with regards to the extension of the building’s future lifespan and its improved usage and resident comfort.

BPT supports the proposed maintenance works to the roof in order to minimise water ingress and protect the existing roof rafters, bringing the building back into efficient and positive use that will aid its future maintenance. We encourage the replacement of insensitive and harmful materials such as the plastic roofing felt that is incompatible with permeable historic fabrics. The replacement of damaged tiles is a necessary loss of historic fabric, and their like-for-like replacement will both weatherproof the building as well as improve its external appearance.

The Trust would recommend that the roof is carefully recorded before works begin in order to document retained areas of historic slates or clay tiles; this will ultimately aid future maintenance works and maximise the future retention of historic roof fabrics. We would also highlight the critical importance of continued, regular upkeep to the lead valley gutter to ensure it is free of blockages or cracking that might result in further water damage.

With regards to the suggested use of Celotex insulation between the roof rafters, we would advise that a more suitable form of insulation is used. Foil-based rigid insulation is often unsuited to historic buildings due to their use as a vapour barrier that can result in a build-up of condensation, as well as the difficulty of installation around roof rafters. Due to existing condensation issues within the roof space, the Trust would advocate the use of a more suitable natural fibre insulation such as wool or hemp; these are more sustainable options that are also capable of absorbing excess moisture whilst maintaining a consistent thermal performance. Loose insulation is additionally better suited to being installed around rafters and minimising any potential thermal bridges that can exacerbate existing moisture problems.

Ultimately, BPT encourages the maintenance and reuse of existing historic buildings, and additionally supports sensitive retrofitting practices to improve energy performance and resident comfort in accordance with Policy CP1 of the Core Strategy and Placemaking Plan. However, we feel that the proposed insulation type is inappropriate and would recommend more permeable, natural options are considered.

Application Number: 19/04464/LBA
Application Date: 11/10/2019
Closing Date: 07/11/2019
Address: Grosvenor Lodge, Grosvenor Place, Lambridge
Our Submission Status: Comment