Conservation Area — Double Glazing
Pane Relief double-glazing for conservation area applications. The information below covers the products and considerations specific to this use case. Use the configurator above to spec your exact dimensions and glass for an instant price.
Clear Double Glazed Unit — Heritage & Listed Building Glazing
Replacing single glazing in a listed building or heritage property requires a unit with minimal visual impact. Our Clear Double Glazed Unit offers the slimmest, most optically neutral sealed unit available — no visible coatings, no tinted appearance, just clear glass that closely replicates the look of original single glazing.
Conservation officers and Historic England assessors examine replacement glazing for visual changes. Low-E coatings can be visible as a slight reflective sheen from certain angles — a detail that sharp-eyed planners will flag. Our clear/clear unit eliminates this concern entirely, offering double-glazing protection with single-glazing aesthetics.
Specification
Two panes of clear float glass separated by a sealed cavity. Available in 24mm (4-16-4) or 28mm (4-20-4) overall thickness to suit your frame rebate.
- U-value: 2.8 W/m²K (air) or 2.6 W/m²K (argon upgrade)
- Light transmittance: ~80%
- Overall thickness: 24mm or 28mm
- Glass: 4mm clear float both panes
Note: this unit does not meet current Building Regulations Part L for heated living spaces. For heated rooms requiring Building Control sign-off, choose our Low-E Argon IGU or triple-glazed range instead.
Made to Measure Double Glazed Unit — Conservation Area
Replacing glazing in a conservation area property requires sensitivity to the building's character. Our made-to-measure units can be manufactured with slim spacer bars and shallow cavity widths to minimise the visible difference between new double glazing and original single panes.
Conservation officers examine the depth of the sealed unit within the frame rebate. A standard 24mm or 28mm unit in a frame designed for 4mm single glass will sit forward of the original glazing line, creating visible shadow differences. We can manufacture slim units from 14mm overall (4-6-4) for the most sensitive applications.
Your Specification, Made to Order
Every made-to-measure unit is manufactured to your exact dimensions by our partner factory. We offer the full range of glass types, coatings, gas fills, and spacer bar options — specify exactly what your project needs.
Self-Cleaning Glazed Unit — Conservation Area Aesthetic
Heritage properties must maintain their appearance — it's often a condition of planning consent. But accessing windows for cleaning in conservation area properties can require scaffolding, which itself may need planning permission. Our Self-Cleaning Glazed Unit keeps heritage glass clean naturally, maintaining the building's appearance without scaffold access.
Many conservation area properties have restrictions on external scaffolding and maintenance equipment. The self-cleaning coating eliminates most routine external cleaning needs — the combination of UV-activated dirt breakdown and rain wash keeps glass acceptably clean between annual professional cleans.
How Self-Cleaning Glass Works
The self-cleaning coating uses a dual-action process:
- Photocatalytic action: Titanium dioxide (TiO2) in the coating reacts with UV light to break down organic dirt at the molecular level — bird droppings, tree sap, pollen, and general atmospheric grime are decomposed on the glass surface.
- Hydrophilic action: The coating makes the glass surface attract water rather than repelling it. Rain spreads into a thin, even sheet instead of forming droplets — this sheet washes away the loosened dirt particles, leaving the glass clean and streak-free.
The coating is applied during glass manufacture and is permanent — it cannot be washed off, scratched away with normal cleaning, or degraded by UV exposure (UV is what activates it).
Self-cleaning glass can be combined with Low-E coatings, toughened or laminated glass, and argon gas fill — no compromise on thermal or safety performance.