BS EN 1096 (Parts 1–4)BS EN 410 (Luminous and Solar Characteristics)Approved Document LCWCT Envelope StandardReviewed Technical Specification
Solar-Control & Selective Low-E Glazing
Magnetron-sputtered microscopic metallic nanocoatings reflecting infrared solar energy while preserving high visual transparency.
Engineering Definition: Float glass coated with off-line magnetron sputtering vapor deposition (MSVD) featuring multiple sub-nanometre silver layers that selectively reflect near-infrared and far-infrared solar radiation while transmitting visible light (BS EN 1096 Parts 1–4 / BS EN 410).
Precision Specification
Composite Architectural Glass Assembly
Multi-Ply Safety Specification
Accessible Static View
Schematic exploded horizontal cross-section showing sequential structural placement.
01
Outer Structural Ply(Thermally Toughened Glass)
10.0mmExternal impact and wind barrier
02
Engineered Interlayer Core(Structural SentryGlas / Acoustic PVB)
1.52mmViscoelastic damping & residual load support
03
Inner Structural Ply(Thermally Toughened Glass)
10.0mmInterior barrier and post-breakage integrity
BS EN 12150 / BS EN 14449 Architectural ReferenceIllustrative diagram — project structural verification required
Physical & Mechanical Performance Characteristics
Safety Class:Supplied annealed or thermally toughened to suit structural wind and thermal stress
Bending Strength:Determined by base glass substrate (annealed fg,k = 45 N/mm² or toughened fb,k = 120 N/mm²)
Thermal Shock Resistance:High solar absorption requires thermal toughening to eliminate thermal stress fractures (delta T > 40K)
Fracture Behaviour:Determined by base glass substrate (toughened or laminated)
Typical U-Value (Ug):1.0 W/m²K to 1.1 W/m²K (standard argon double glazed unit, EN 673)
Acoustic Reduction (Rw):Rw 31 dB to Rw 42 dB dependent on configuration
Max Sheet Dimension:Up to 3210mm × 6000mm (jumbo architectural sheets)
Density & Mass:2.50 kg/m² per mm glass thickness
Key Architectural Advantages
- •Drastically reduces commercial solar heat gain (g-value down to 0.28), preventing summer office overheating without dark tinted glass
- •High selectivity: admits pleasant natural daylight (LT 60–70%) while blocking over 70% of infrared solar heat
- •Dual performance: combines solar control with low-emissivity winter heat retention (Ug 1.0 W/m²K)
Critical Engineering Constraints
- •Soft-coat magnetron coatings are delicate and oxidize if exposed to atmosphere; MUST be edge-deleted and sealed inside an IGU cavity
- •Coating orientation is critical: reversing the unit during glazing places coating on incorrect surface, compromising thermal and visual performance
- •High thermal stress differential between shadowed edge and sunlit center demands mandatory thermal stress calculations
Fabrication & Edge Processing Tolerances
Cut After Toughening:PROHIBITED (Catastrophic Fracture)
Heat Soak Testing (HST):Recommended to BS EN 14179
Dimensional Tolerance:Panes <= 2000mm: ±2.0mm; panes > 2000mm: ±3.0mm
Thickness Tolerance:4–6mm: ±0.2mm; 8–10mm: ±0.3mm; 12mm: ±0.3mm
Flatness & Roller Wave:Overall bow max 3.0mm/m; local roller wave max 0.15mm/300mm for facade visual reflection quality
Hole & Cutout Geometry Rules:Holes must be cut prior to toughening; edge deletion around holes not required if covered by hardware gaskets
Must be heat treated (temperable coating) in convection furnaces with specialised optical pyrometers.
Structural Design Basis (Eurocodes / BS EN 16612)CEN / BSI Harmonised
Characteristic Strength:Toughened solar control plies: fb,k = 120 N/mm² (BS EN 12150-1)
Elastic Modulus (E):70,000 MPa
Poisson's Ratio (ν):0.22
Linear Expansion (α):9.0 × 10⁻⁶ K⁻¹
Design Bending Stress Formula (BS EN 16612):BS EN 16612 design bending strength with thermal stress verification to CWCT TN 66
Architectural Specifier Checklist
Verify these technical criteria prior to contract documentation:
1Specify target Selectivity (Light Transmittance LT % divided by Solar Factor g %).
2Ensure specification mandates edge-deletion (removal of 10–12mm coating border) prior to secondary unit edge sealing.
3Specify base substrate: low-iron (extra clear) float substrate avoids green tint when combined with neutral high-performance coatings.
4Mandate Heat Soak Testing (HST to BS EN 14179) on all toughened external solar control panes.
Frequent Commercial Applications
Network Procurement Routing
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Advanced architectural glazing destination specialising in next-generation high-performance coatings, BIPV (building integrated photovoltaics), and dynamic electrochromic glass.
Recommended Action: Conduct thermal model comparison and consult specialist facade glass fabricators.
Proceed to NEXTGEN.GLASSReviewed by: Senior Facade Physics Engineer, BuyGlass Editorial Panel
Last Standard Verification: 2026-10-30