Proposal
Internal and external alterations to replace the single-glazed sashes in the four dormer windows at the top of the property by double glazed (‘slimline’) ones.
Our Response

3 Lansdown Place East forms part of the Grade II Georgian terrace situated within the Bath conservation area and World Heritage site. It additionally forms part of the complementary planned setting of the Grade I Lansdown Crescent. The area remains hugely significant in its presentation of Georgian monumental architecture and town planning, and the designed visual homogeneity and harmony throughout both Lansdown Place East and Lansdown Crescent which contributes to Bath’s World Heritage OUV. Therefore, 3 Lansdown Place East’s architectural value is primarily related to its aesthetic uniformity both individually and as part of the wider terrace.

In principle, BPT is supportive of sensitive sustainability retrofits, where deemed appropriate, within the historic environment. Our position in a relation to the appropriateness of a range of measures is set out in our publication Warmer Bath: A Guide to Improving the Energy Efficiency of Traditional Homes in the City of Bath. In light of the current Climate Emergency, we appreciate the urgency of reducing energy consumption and carbon production, as well as upgrading our existing historic housing stock to meet modern standards of living and thermal performance.
However, the suitability of energy-efficient retrofits in relation to heritage significance, effectiveness, and the risk of unintended consequences must be assessed on a case-by-case basis.

In this particular case we recognise this proposal would result in less than substantial harm and no loss of historic fabric. The double paned glass at high dormer window level would have little visual impact on the collective appearance of windows in this house and terrace. However, we have concerns about the glazing bar profile proposed.

Unfortunately, we are unable to make a proper assessment of this element of the application as some important information is currently missing. There are no existing window details, close up photographs or measured sections against which the proposed sections can be compared. We would therefore recommend that sections of the existing windows are submitted to enable the LPA to make a proper assessment regarding any potential change in glazing bar thickness and consequently the overall visual character of the windows. The provision of existing and proposed glazing (glass) thickness measurements is additionally encouraged. This could be an opportunity to use thermal glass.

We also question the appropriateness of the glazing bar profile proposed, which is probably proposed to match existing. Given the age of the original building an ovolo profile could be considered more appropriate. This might be a good opportunity to reinstate this historic profile.
BPT is very interested in working with the applicant to reach an acceptable solution and getting better understanding of the existing window condition and design. Ultimately, we feel that subject to detail the LPA should approve this application.

It could help provide an invaluable opportunity to monitor the thermal and acoustic efficiency of the windows, before and after, whilst also observing any additional repercussions such as changes in humidity levels. This information could then be used to more accurately assess the suitability of slimline installation in Bath’s historic building stock.

The Trust acknowledges this scheme’s potential to establish a precedent for the installation of windows with higher energy efficiency within Bath’s historic terraces and crescents, with a resulting effect on the aesthetic, architectural, and historic integrity of Bath’s historic environment. Therefore, we feel that if proposal such as this could be got right, and before and after data collected to evidence improvements in efficiency, it could be used as a best practice example that would help further future retrofits to buildings of historic significance within Bath.

Application Number: 20/00024/LBA
Application Date: 13/01/2020
Closing Date: 13/02/2020
Address: 3 Lansdown Place East, Lansdown
Our Submission Status: Comment