Historic Scotland has published their latest technical paper. Technical Paper 23 looks at the thermal assessment of internal shutters and window film applied to traditional single glazed sash and case windows. The paper is based on a trial of both methods at a traditional cottage in Fife owned by the National Trust.
Shutters and window film are both inexpensive and minimally invasive measures and the paper shows both to assist in reducing the U-value compared to the window which had no measure in place. The shutter performed particularly well but it must be kept in mind that shutters are unlikely to be during day light hours. The window film performed less well but can be used 24 hours a day.
Historic Scotland continues to research energy efficiency measures and materials. With the consultation on a minimum EPC for the private rented sector and property sales expected in the spring, this growing body of research is increasingly important.
The technical paper can be found at http://conservation.historic-scotland.gov.uk/publication-detail.htm?pubid=10853&searchterm=&category=&date=&page=1