Conservation Area — Triple Glazing
Pane Relief triple-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.
28mm Triple Glazed Unit — Heritage-Friendly Triple Glazing
Working on a period property in a conservation area? Our 28mm Triple Glazed Unit offers the slimmest triple-glazed profile in our range — making it the most planning-friendly option for heritage-sensitive projects. At just 28mm, this unit closely matches the sightline profile of traditional double glazing, satisfying conservation officers concerned about visible changes to window proportions.
Many conservation area applications are rejected because the proposed glazing is too thick, altering the reveal depth and shadow lines. Our 28mm unit addresses this by keeping the overall thickness comparable to standard 24–28mm double glazing — a difference of millimetres that can make or break a planning application.
Technical Performance
This Energy A+ rated triple glazed unit packs three panes of precision-cut float glass into a 28mm sealed unit — the same thickness as many standard double-glazed units. The configuration uses 4mm-8mm-4mm-8mm-4mm glass-cavity-glass layering with argon gas fill and a soft-coat Low-E coating on surface 5.
36mm Triple Glazed Unit — Maximum Performance for Heritage Projects
When a listed building or conservation area project demands the absolute best thermal performance achievable, our 36mm Triple Glazed Unit delivers a U-value of 0.6 W/m²K — the highest performance you can achieve while still using a standard sealed unit format. For heritage projects where every thermal improvement counts, this is the pinnacle.
We work with conservation officers, heritage architects, and Historic England to ensure our 36mm units are specified correctly for listed buildings. Where slim-profile 28mm units are preferred for visual reasons, the 36mm can be used on less visible elevations (rear, side, roof) to maximise overall building performance while maintaining heritage character on the principal facades.
Peak Thermal & Acoustic Performance
The 36mm build-up uses 4mm-12mm-4mm-12mm-4mm configuration with double soft-coat Low-E coatings and the option of krypton or argon gas fill. The 12mm cavities are at the optimal width for gas-fill thermal performance, delivering the lowest U-value achievable in a standard triple-glazed format.
Acoustic Triple Glazed Unit — Conservation Area Noise Solution
Period properties in busy urban conservation areas face a double challenge: intrusive noise from modern traffic levels, combined with planning restrictions that limit visible changes to the building. Our 44dB Acoustic Triple Glazed Unit delivers professional-grade noise reduction in a sealed unit format that fits existing window frames without altering the external appearance.
Conservation officers focus on external appearance — sightlines, glazing bar profiles, and reveal depths. Our acoustic unit achieves its 44dB rating through asymmetric glass thickness and laminated interlayers, not by adding bulk. The overall thickness can be specified to match your existing frame rebate depth.
How 44dB Acoustic Glazing Works
Standard sealed units use identical glass thicknesses on all panes — which creates resonance at specific frequencies, allowing noise through. Our acoustic units use asymmetric glass configurations (typically 6mm outer, 4mm middle, 6.4mm acoustic laminated inner) that break up resonance patterns across the full frequency spectrum.
The acoustic PVB interlayer in the laminated pane is specifically formulated to dampen sound vibration — it's softer and more viscoelastic than standard PVB, absorbing energy rather than transmitting it. Combined with argon gas fill and Low-E coating for thermal performance, this unit doesn't sacrifice energy efficiency for noise reduction.