Pilkington K Glass™ S
Pilkington K Glass™ S is a UK-manufactured, soft-coated, low-emissivity (low-e) glass designed to deliver outstanding thermal insulation and energy performance. With its highly neutral appearance, high solar factor, and superior light transmission, it’s the ideal choice for fabricators, glaziers and installers looking to optimise Window Energy Rating (WER) and meet regulatory requirements (e.g. Part L of the Building Regulations in England).
Key Benefits for UK Fabricators & Glaziers
- Exceptional thermal insulation – low-e coating reflects heat back into the room, reducing heat loss.
- Optimised solar gain – allows free heat from the sun (passive solar gain) to enter the home, maximising overall energy performance.
- A+ and A++ Window Energy Ratings – can help windows achieve up to top-tier WERs across PVC-U, timber and aluminium frames.
- Neutral aesthetics – excellent light transmission with no heavy tint, ideal for modern UK homes.
- Flexible processing – available in annealed form and can be toughened or laminated without compromising performance or appearance.
- Fabrication friendly – no edge deletion required when used with Pilkington UK-approved sealants.
Supporting UK Regulations & Energy Efficiency Goals
Pilkington K Glass™ S is designed to help fabricators and installers meet today’s strict energy standards and prepare for the future.
- Helps windows and doors comply with Part L of the Building Regulations in England and Wales and Section 6 of the Technical Handbook in Scotland.
- Helps homeowners lower heating bills and carbon emissions – supporting the UK’s net-zero ambitions.
- Critical to windows achieving low U-values and optimal Window Energy Ratings (WERs) in double and triple glazing.
Energy and Environmental Benefits
Calculations(1) indicate the following typical annual savings when replacing single glazed timber windows in a semi-detached house with A+ rated windows incorporating Pilkington K Glass™ S double glazing units:
- £321 saved in energy costs a year
- 0.83 tonnes reduction in annual carbon emissions
(1) Calculated using the GGF Energy Savings Calculator (https://www.ggf.org.uk/myglazing/environmental-hub/energy-calculator/)
Applications in the UK Market
Pilkington K Glass™ S is suitable for a wide range of residential and light commercial projects:
- New-build housing
- Replacement and retrofit windows
- Conservatories and garden rooms
- Energy-efficient upgrades to existing homes
Fabrication & Processing
Pilkington K Glass™ S is available in multiple formats to suit trade requirements:
- Annealed for standard double and triple glazed units
- Toughened for safety and strength applications
- Laminated for enhanced acoustic, security or safety performance
The coating for Pilkington K Glass™ S should normally be positioned on surface #3 of a double glazing unit (counting from the outside), delivering the best balance of solar gain, insulation, and aesthetics.
Ready to specify Pilkington K Glass™ S?
Contact your local Pilkington UK representative today for technical guidance, samples, or details of your nearest UK supplier.
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September 2025
Version UK:2.1.1