We specialise in secondary glazing installations that balance thermal performance with practical considerations. Our approach prioritises measurable results over marketing claims, focusing on what actually improves comfort and reduces energy consumption.
Secondary glazing emerged as a practical solution during the energy crises of the 1970s, when wholesale window replacement proved economically unfeasible for most property owners. The technology has evolved substantially since those early implementations, with modern systems delivering performance that rivals double glazing in many applications.
We entered this sector after observing the gap between what installers claimed and what thermal imaging actually revealed. Too many installations failed to deliver promised improvements because installers overlooked basic principles like air sealing and frame precision.
Effective secondary glazing depends on creating a sealed air gap between the existing window and the secondary pane. The gap dimension influences both thermal and acoustic performance. Too narrow, and convection currents transfer heat across the gap. Too wide, and the same convection undermines insulation value.
We measure existing window reveals precisely before fabricating frames. Standard tolerances in the industry often leave gaps that allow air infiltration, negating much of the theoretical insulation benefit. Our frames are manufactured to within 2mm of surveyed dimensions.
Glass selection varies by application. Low-emissivity coatings reduce radiant heat transfer but offer minimal acoustic benefit. Laminated glass improves sound dampening but adds weight that requires stronger framing. We match glass specification to the primary performance objective rather than using a single standard across all installations.
Listed buildings present particular challenges. Planning authorities typically resist alterations visible from the street, even when those alterations improve energy efficiency. Secondary glazing offers a solution because it operates on the interior face of existing windows, leaving the external appearance unchanged.
Conservation officers sometimes express concern about moisture accumulation between the original window and secondary glazing. This risk exists primarily when the original window has poor ventilation. Our installations include discreet ventilation slots positioned to allow air circulation without compromising thermal performance.
We maintain relationships with conservation officers across multiple local authorities, which helps navigate the approval process. Our installations are fully reversible, an important consideration for properties where any permanent alteration to historic fabric would be unacceptable.
We conduct thermal imaging surveys both before and after installation for clients who request them. The infrared imagery provides visual evidence of heat loss patterns and demonstrates where secondary glazing has eliminated thermal bridging.
Acoustic performance testing uses calibrated sound level meters to establish baseline external noise levels and post-installation measurements. While we cannot control external sound sources, comparative measurements taken under similar conditions reveal the actual noise reduction achieved.
Energy bill analysis over subsequent heating seasons provides the ultimate performance verification. We encourage clients to monitor consumption patterns, though numerous variables influence heating costs beyond window performance alone.