Lecturer in Architecture and Environment, Dr W. Victoria Lee, has published a new guide for homeowners based on her research into the conservation of traditional sash and case windows, available online. The project was funded through a University of Edinburgh College of Arts, Humanities and Social Sciences (CAHSS) knowledge exchange and innovation grant.

Victoria says: “Windows are important architecture features of historic buildings. But they are also a significant source of heat loss in winter, making them a significant vulnerability in energy conservation. At the same time, historic buildings such as listed buildings and homes in conservation areas have special restrictions on what modifications can be made to protect their heritage characteristics. This can make retrofitting historic windows sometimes tricky and even daunting for homeowners to tackle. 

“This project came to be because I wanted to understand how the issues concerning the two conservations – that of heritage and energy – influence homeowners’ perceptions and retrofit decisions, and how the process can be demystified. Often people think that you can’t do anything to improve the energy efficiency of historic windows due to heritage protection, but this is not necessarily the case.”

Having interviewed and followed the retrofit journeys of local residents, Victoria collaborated with Edinburgh World Heritage to distill the lessons learned into her guide.

The aim is to raise best practices awareness of improving energy efficiency and occupant satisfaction whilst conserving heritage in historic properties.

Historic sash and case windows are usually made from good quality slow-grown wood with thin timber bars called astragals, which divide the windows into individual panes of glass. This window pattern (most common is ‘6 over 6’ or ‘Georgian’) is a prominent feature of historic buildings in Edinburgh and should be conserved whenever possible. 

While some historic windows have their glass replaced in the past, many sash and case windows in Edinburgh still have the ‘wavy’ or ‘wobbly’ historic glass, an artefact from the historic manufacturing process. The guide suggests some ways of improving the thermal performance of these windows whilst retaining as much of the historic material and design as possible. 

In the long run, Victoria hopes the guide will lead to more historic residential windows in Edinburgh being retrofitted in ways that balance heritage preservation, energy efficiency, and occupant usability.

The digital guide, 'Retrofitting History Sash and Case Windows - A Quick Start Guide' comes complete with clickable links and checklists - follow the link in the 'Find out more' section below to access it.

Victoria will have a stall at the Edinburgh Futures Institute Doors Open Day on Saturday 28 September, where you can ask her questions or pick up a printed copy of the booklet.