Refurbishment and Restore Issue 18 2019 | Page 20

Glazing comparison table Single Glazing Double Glazing Slim Double Glazing Vacuum Cavity Glazing 4-8mm thick glass which can be float, crown or cylinder depending on the production method. Two sheets of 4-6mm float glass separated by a spacer bar. Space between two panes (cavity) typically 16-20mm and filled with inexpensive inert gas. Two sheets of 4mm float glass separated by a spacer bar. Cavity between glass panes is reduced to 4-6mm and filled with more expensive inert gas. An inner pane of clear float glass and an outer pane of low-e glass separated by microdots. Cavity between glass panes is reduced to 0.2mm and air is extracted to give a vacuum. Pros: Pros: Pros: Pros: • Traditional, with no double reflection • Inexpensive • Limited double reflection • Good energy efficiency • Moderate energy efficiency • No discernible double reflection • Inexpensive • Long lifespan • Moderate lifespan • Good energy efficiency • Better sound insulation • Long lifespan • Ultra-thin glazing: Pilkington Spacia™ is 6.2mm. Cons: Cons: Cons: Cons: • Poor energy efficiency • Non-traditional with pronounced double reflection • Poor lifespan • Plug on face of unit and tiny microdots within glass • Poor acoustic performance • Heavier and thicker glazing typically 24mm requires larger frame sections Gowercroft Joinery is the first window manufacturer to have incorporated Pilkington Spacia™, into a traditionally crafted range of Heritage windows made with modern materials like Accoya ® , (a modern modified timber whose cellular structure has been treated to increase its durability, stability and longevity) sprayed with a unique formulation of protective paint, guaranteed to deliver zero maintenance for 10 years. Whilst the range does not claim to use real putty to secure the glass panes like the windows of yesteryear - in a modern high-performance window this would be incongruous - the putty line is replicated in the outer profile. Although more regular looking than traditional putty, it does significantly improve security and coating longevity. Similarly, modern seals that are designed to keep the windows weather-resistant are neatly concealed within the joinery. Arguably, any attempt to provide an acceptable modern solution for a listed property will involve some degree of compromise. The perfect window for ‘modern living’ in a heritage home may not yet have been designed to everyone’s satisfaction, but conservation officers, specifiers and owners of listed properties do now have options, including some highly functional, future- proofed and genuinely sympathetic modern products. For more information about Gowercroft Joinery, telephone: 01773 300 510. Fax: 01773 300 511 Email: [email protected] Web: www.gowercroft.co.uk For more information about Pilkington Spacia™ visit www.pilkington.co.uk/spacia 20 - www.refurbandrestore.co.uk • Expensive • Limited unit size • Expensive