See how secondary glazing can benefit heritage homes with Selectaglaze and the Macartney House
When facing the need for 21st-century thermal solutions, Selectaglaze’s expertise in secondary glazing in heritage homes meant they were an easy choice for the residents of the Macartney House.
Dating back to 1717, the Grade II listed building was once described as “the prettiest-situated house in England” and overlooks the Royal Observatory in Greenwich Park.
Over time, the property has undergone remodelling and development, converted into flats with the introduction of new bay windows, additional fireplaces and enlarged window openings, all approved by the Crown Owners and Courts. A cellar conversion has even become a Garden Flat.
Owner of the property Robert Barnes has made significant renovations in line with Historic England’s guidance.
Meeting modern efficiency standards with secondary glazing
In 2022, Mr Barnes approached Selectaglaze to evaluate Macartney House and to recommend the most appropriate and sympathetic, thermal solution.
The solution for lowering energy costs was to use secondary glazing glazed with 6mm toughened low-E (low emissivity) glass. The metallic coating on low-E glass was placed facing the window cavity which helped by significantly reflecting heat, back into the building.
Selectaglaze secondary glazing was carefully applied over the existing windows to match the period mullions and framework. Slim timber subframes were specially machined in our joinery shop and factory finished to match the semi-gloss white frames in RAL colour: 9910. The magnificent views of Greenwich Park remained unaffected, thanks to our heritage slimline vertical sliding units (Series 20).
“The secondary glazing is all the better because you don’t even notice it’s there. It’s so unobtrusive you barely see it. Without doubt it keeps the heat in better than before, noticeably overnight. And also noticeable in our downstairs rooms that are less frequently used but now much more amenable.” -Robert Barnes
Working with the specifications of heritage homes was no problem for Selectaglaze
So far this was relatively straightforward. However, two beautiful prominent bay areas required more attention and time due to the angles and number of panes involved.
With the help of our CAD team, the curved windows were designed as single side-hung casements (Series 41).
These heavy-duty hinged systems were particularly suited for these large windows. Special beading options allowed for thicker glass to be incorporated providing enhanced noise insulation whilst also maintaining the improved thermal insulation.
All work was in accordance with Historic England Advice Note 16
Of course, it is also important to ensure the secondary glazing can be wholly reversible just in case it needed to be removed later without damage to the linings or sills. By working closely with the architects, Listed Building Consent was sought but not required as there would be no damage to the window frames and no additional exterior window sightlines.
Now that work in Flat 7 has been completed, the rest of the property will be undergoing further installation of secondary glazing with Selectaglaze.
