Zprávy památkové péče 2023, 83(2):159-175 | DOI: 10.56112/zpp.2023.2.05

Historical windows and energy performance: the case of Modernist architecture

Alexander Kuric, Kristýna Schulzová

Historical windows are under pressure in the current environment of tightening energy performance requirements, resulting in many cases in widespread replacement with new windows. Monuments of modernist architecture, where windows are an exceptional carrier of not only historical but also aesthetic value, are particularly vulnerable to this trend. The aim of this paper is to investigate the thermal insulation properties of typical modernist windows in more detail and to examine the effectiveness of additional measures to improve them. To do so, we use model-based software calculations combined with thermal imaging. From the point of view of the first objective, the practically known problematic nature of metal windows was shown or, more precisely, confirmed. A comparison of double and double-hung windows is noteworthy, confirming some progressive views from the interwar period that advocated double-hung windows. In terms of additional measures, sealing the sashes and replacing the original glazing with double glazing are shown to be effective and potentially widely applicable, while, taking into account other factors, the replacement of the external glazing is generally the most advantageous; in this case the thermal transmittance of the original window can be reduced by up to 60%. The paper thus confirms the conclusions of previous research on this topic, while expanding them with further context and detail.

Keywords: windows; Modernism; monument renovation; energy performance; adaptation

Published: November 29, 2023  Show citation