Rates of Window Glass Replacement in Historic Buildings: A Bespoke Computational Analysis Approach for Scottish Planning Authorities Listed Building Consent Data

• Published in: The historic environment (London) Vol. 11; no. 1; pp. 76 - 90
• Main Authors: Phipps, Caitlyn, Forster, Alan M., Kennedy, Craig J.
• Format: Journal Article
• Language: English
• Published: Routledge 02.01.2020
• Subjects: glass; glazing; Heritage; listed building; planning
• ISSN: 1756-7505; 1756-7513
• DOI: 10.1080/17567505.2020.1709282

Since the Middle Ages advances in manufacture and chemical processes have improved standards of window glass production. This can be identified through decreasing levels of visible imperfections in window glass made ostensibly, prior to the 1950s. The importance of retaining historic window glass cannot be understated with the inherently imbued cultural, aesthetic and historical value. Windows are the element of historic buildings most at risk from replacement by newer equivalents. In order to quantify the extent to which historic windows are replaced, we rely on data published by local authorities. However, this data can be difficult to access and analyse due to the disparate and complex nature of local authority websites. Here we introduce a bespoke computer programme, written and developed specifically to extract planning data with its disparate and multifaceted parameters. The programme enables trends in window replacement over time to be discerned. Within local authorities, both general planning and listed building applications related to windows have a high approval rate. Listing appears not to offer significant protection for windows. Despite the promotional efforts of national and international heritage organisations in favour of repairing and upgrading existing windows, in practice, these appear to have little effect at local level.