Header image of bay with secondary glazing - technical drawings - timber

Heritage and secondary glazing in perfect harmony


Treat Of The Month


refurbishment and conservation, acoustic secondary glazing, thermal secondary glazing, fixing methods

With over 50 years experience our team were undaunted by the technical and aesthetic considerations posed by a recent treatment. Named in the Domesday Book, this beautiful Grade II Listed property contained architectural features spanning from the 16th through to the 19th century.  Having lived in the property for over 20 years its owners had become increasingly concerned about the impossibility of achieving thermal comfort; to adequately heat any room they would have to turn up the radiators and keep the door shut. With their growing worry about climate change; the owners of this property wanted to make their property more energy efficient whilst enjoying the luxury of an ambient temperature throughout. With its Listed status, the only feasible solution was to add secondary glazing. In addition to the heating problems the property also suffered from noise ingress. Over their occupancy, the nearby road had become increasingly busy and as a result, noise had steadily increased. Our independent frame design decouples the secondary from the primary, forming an acoustic gap between the two. This method is highly effective in both reducing heat loss and deadening sound.  Although sustainability and comfort were important, unsurprisingly the owner's paramount concern was to preserve the irreplaceable sense of history encapsulated in the building. Great care and attention to detail, together with creativity and ingenuity were required to produce an effective yet non-obtrusive treatment. Ever up for the challenge, we photographed and measured all the windows designated for acoustic/thermal secondary glazing. The eclectic nature of the project required the specification of seven different Series from our existing range. Bay closeup angles accommodated by secondary timber frame No true openings non-uniform angles In addition to a large number of Series and styles, the treatment presented a wide range of installation challenges. One particular primary window presented with no true openings. This was further complicated by each window being set in a bay with no uniform angles. With most treatments, an initial measurement is followed by a survey which informs the production of both timber grounds and secondary units. However, in this instance, the complexity of the treatment required an additional survey. The first survey was undertaken to inform the creation of timbers to allow for the installation of secondary units. Once these were in situ the second survey then took measurements from the new secondary timber frame. It was these measurements that were then used to inform the manufacture of secondary glazing. Timber template drawings - secondary glazing frame Angled timbers for true rectangular openings for Series 20 vertical sliding units Back plate timber - technical drawings Back plate timber for installation of Series 41 hinged casement units During the final installation, the timbers were further scribed to accommodate the dado and skirting boards. Skirting and dado rail detail Dado and skirting detail Two bespoke Series 20 vertical sliding units together with a Series 41 double hinged casement secondary unit as specified at the surveying stage were subsequently installed. Scribed timbers also accompanied the installation to preserve historic features. “We have been so impressed by the design of the windows, frames and the bespoke options. External noise has been all but eliminated and the airtight fittings and thickness of glass will significantly reduce our energy bill. The framings actually enhance the inherent beauty of the Georgian windows and in no way obscure the views outside. Initially, we were focused on the windows at the back of the house but were so pleased with the outcome we doubled our order to include the front upper levels of the Georgian house. The Selectaglaze product has certainly transformed the living experience of our home.” –  Owners of Blue Mills bay window - with secondary glazing blending into whole Optimal fit – low visual impact – maximum benefits We always aim to fit our secondary units to minimum tolerances. This attention to detail ensures an optimal fit. The complexity of this treatment required additional steps to achieve this standard. As a company, we will always go the extra mile to produce secondary glazing treatments that are 'best in field'. Harmony has been restored to this beautiful property; whilst modern thermal integrity has been added to the windows to make it both sustainable and comfortable for future generations.