Double Glazing – Common Questions & Answers

Installation & Maintenance

1. How long does it take to install double glazing?
   Installation usually takes a few hours per window, depending on size, access, and frame complexity.

2. How do I clean double-glazed windows?
   Use mild detergent and a soft cloth. Avoid abrasive cleaners or scouring pads that can damage coatings or seals.

3. Can double glazing be repaired?
   Yes, depending on the issue. Minor faults such as draughts or loose hardware can be repaired, but condensation between panes usually requires replacing the sealed unit.

4. How long does double glazing last?
   Typically 10–20 years with proper installation and maintenance. Frame quality, seal integrity, and environmental exposure affect lifespan.

5. Can I replace single glazing with double glazing?
   Yes. In most cases, the window frames can be modified or replaced to accommodate double glazing.

Energy Efficiency

6. Does double glazing save energy?
   Yes. It reduces heat loss in winter and heat gain in summer, lowering energy bills and improving comfort.

7. How much can I save on energy bills with double glazing?
   Savings vary, but many households experience up to 30% reduction in heating and cooling costs.

8. Does double glazing help in summer?
   Yes. The air or gas layer between panes reduces solar heat gain, keeping interiors cooler.

9. What is the U-value of double glazing?
   Energy-efficient double glazing typically achieves U-values between 1.2 and 2.0 W/m²K — lower numbers mean better insulation.

10. Is triple glazing better than double glazing?
    Yes. Triple glazing provides superior insulation, but it is heavier and more expensive, offering smaller benefits in mild climates.

Types & Materials

11. What types of glass are used in double glazing?
    Common types include toughened, laminated, low-emissivity (Low-E), and self-cleaning glass.

12. What is Low-E glass in double glazing?
    Low-E (low-emissivity) glass has a thin coating that reflects interior heat back inside while letting in natural light.

13. Can double glazing be tinted?
    Yes. Tinted or reflective glass reduces glare, UV exposure, and heat gain.

14. What is toughened glass in double glazing?
    Toughened glass is heat-treated for increased strength and safety. When broken, it shatters into small, blunt fragments.

15. What frame materials are used for double glazing?
    Frames are commonly made from uPVC, aluminium, timber, or composite materials, each with different durability and aesthetic qualities.

Cost & Pricing

16. How much does double glazing cost?
    Prices vary by size, design, and materials, but typical double-glazed windows cost $200–$1,000 per unit.

17. Is double glazing worth the cost?
    Yes. It provides long-term energy savings, comfort, and higher property value.

18. Can I get a grant for double glazing?
    In some regions, government rebates or energy-efficiency grants are available for upgrades.

19. Does double glazing increase property value?
    Yes. Buyers value homes with lower energy costs, enhanced comfort, and modern appearance.

20. Is financing available for double glazing?
    Yes. Many suppliers offer payment plans or finance options to spread the cost.

Security & Safety

21. Is double glazing more secure than single glazing?
    Yes. It’s harder to break and often features advanced multi-point locking mechanisms.

22. Can double glazing be made burglar-resistant?
    Yes. Laminated or toughened glass increases impact resistance and security.

23. Does double glazing prevent condensation?
    Yes. The insulated gap reduces the temperature difference that causes internal condensation.

24. Can double glazing reduce UV damage?
    Yes. Certain coatings block up to 99% of harmful UV rays, protecting furnishings and flooring.

25. What happens if double glazing breaks?
    If toughened glass breaks, it shatters into small, safe fragments; laminated glass stays intact due to its interlayer.

Customisation & Aesthetics

26. Can I get double glazing in different colours?
    Yes. Frame colours and glass tints are available to suit any design style.

27. Does double glazing affect the appearance of my home?
    Yes. It can enhance curb appeal, providing either modern or traditional finishes.

28. Can double glazing be customised?
    Yes. Options include decorative bars, patterns, and various opening mechanisms.

29. Can I get double glazing for period properties?
    Yes. Heritage-style double glazing replicates traditional designs while improving insulation.

30. Does double glazing affect window opening styles?
    No. It is compatible with casement, sliding, tilt-and-turn, and other designs.

Climate & Environmental Impact

31. Is double glazing good for cold climates?
    Yes. It retains indoor heat and reduces heating costs in winter.

32. Does double glazing help in hot climates?
    Yes. It prevents excess heat gain, lowering air-conditioning demand.

33. Is double glazing eco-friendly?
    Yes. By reducing energy use, it lowers your overall carbon footprint.

34. Can double glazing be recycled?
    Yes. The glass, aluminium, and uPVC components can be recycled.

35. Does double glazing reduce greenhouse gas emissions?
    Yes. Lower energy consumption directly reduces CO₂ emissions from heating and cooling.

Common Issues

36. Why is my double glazing misting up?
    Condensation between panes means the seal has failed — the sealed unit must be replaced.

37. Can double glazing make my house too warm?
    In hot climates, choose solar-control coatings or ensure proper ventilation to prevent overheating.

38. Why does my double glazing have condensation on the outside?
    This is a sign of good insulation — it shows minimal heat loss through the glass.

39. Is double glazing soundproof?
    It reduces external noise significantly, though complete soundproofing requires laminated acoustic glass.

40. Can I repair a broken seal in double glazing?
    No. Once the seal fails, the entire insulating glass unit (IGU) must be replaced.

Future & Trends

41. What is smart double glazing?
    Smart (electrochromic) glass changes transparency automatically or by switch in response to light, heat, or electricity.

42. Are there self-cleaning double-glazed windows?
    Yes. Self-cleaning coatings use sunlight to break down dirt, which is then rinsed off by rain.

43. What’s the future of double glazing?
    Emerging technologies like vacuum glazing and dynamic smart glass offer thinner, more efficient alternatives.

44. Can double glazing be retrofitted to existing frames?
    Yes, provided the existing frames are structurally sound and suitable for double-glazed units.

45. Is there a best brand for double glazing?
    Several reputable brands exist — the best option depends on quality, warranty, local service, and budget.