Buy UPVC Double Glazing Windows Direct from UK Manufacturer
Window Supply Direct manufactures high-quality UPVC double glazing windows with prices starting from just £92.42 + VAT. By ordering direct from our UK factories, you'll save 40-60% compared to showroom brands like Everest, Anglian, or Safestyle. All our double glazed windows feature 28mm sealed glass units with U-values as low as 1.2 W/m²K, achieving A+ energy ratings that exceed UK Building Regulations. Choose from over 20 window styles, multiple colours, and made-to-measure sizing with widths from 400-2500mm and heights from 600-2100mm.
Every UPVC double glazing window is manufactured using premium 70mm profile systems from leading suppliers including Eurocell, Rehau, and Veka. All windows meet British Standard BS 7950, come FENSA approved, and include a comprehensive 10-year manufacturer guarantee. Order online with instant pricing—no sales pressure
What is UPVC Double Glazing?
UPVC double glazing consists of two panes of glass separated by a sealed air or gas-filled cavity, typically 16-20mm wide. This insulating layer dramatically reduces heat transfer compared to single glazing, keeping your home warmer in winter and cooler in summer. The UPVC (Unplasticised Polyvinyl Chloride) frame provides a durable, weather-resistant structure that never needs painting and lasts 20-25 years with minimal maintenance.
UPVC double glazing remains the most popular choice for UK homes, offering the ideal balance between performance, durability, and affordability. While triple glazing provides marginally better insulation, double glazing delivers excellent thermal efficiency for most UK climate zones at a significantly lower cost.
Modern UPVC double glazing windows from Window Supply Direct feature:
- 28mm sealed glass units with argon gas filling for superior insulation
- U-values as low as 1.2 W/m²K (exceeding Building Regulations requirement of 1.4 W/m²K)
- A+ energy efficiency ratings that could reduce heating bills by 15-20% annually
- Multi-point locking systems with anti-drill, anti-pick cylinders
- Internally glazed units for enhanced security
- Trickle vents for Building Regulations compliance
- Low-E (low emissivity) glass coating to reflect heat back into your home
Why Choose Double Glazing over single or triple glazing?
Double Glazing vs Single Glazing
Single glazed windows are no longer compliant with UK Building Regulations for replacement windows and offer minimal insulation. Upgrading from single to double glazing can reduce heat loss by up to 73%, dramatically cutting your energy bills and improving home comfort. Double glazed UPVC windows also provide significantly better sound insulation—reducing external noise by 20-30 decibels—and eliminate condensation issues common with single glazing.
Double Glazing vs Triple Glazing
While triple glazing offers marginally better thermal performance (U-values from 0.8 W/m²K), double glazing provides exceptional value for most UK applications:
- Cost Difference: Double glazing costs 30-40% less than triple glazing
- Energy Savings: Double glazing with U-value 1.2 W/m²K already exceeds Building Regulations
- Weight: Double glazed units are lighter, reducing strain on hinges and handles
- ROI: Double glazing offers faster return on investment for standard UK homes
- Performance: In the UK's moderate climate, double glazing provides adequate insulation
Triple glazing is best suited for Passivhaus projects, extremely exposed locations, north-facing rooms, or areas with significant external noise. For standard replacement projects and most new builds, double glazing delivers excellent performance at the best price point.
UPVC Double Glazing Window Prices 2026
How Much Do UPVC Double Glazing Windows Cost?
Window Supply Direct offers the UK's most competitive double glazing prices by selling direct from the factory. Our supply-only prices eliminate showroom overheads, commissioned salespeople, and unnecessary markups.
Our Double Glazing Price Range:
- Fixed Double Glazed From £92.42 + VAT
- Casement Double Glazed From £139.87 + VAT
- Top Hung Double Glazed From £118.89 + VAT
- Tilt & Turn Double Glazed From £190.00 + VAT
- Fixed Triple Glazed From £129.15 + VAT
- Casement Triple Glazed From £181.84 + VAT
Compare Showroom Prices
Traditional showroom brands like Everest, Anglian, and Safestyle typically charge £500-900 per window installed for standard UPVC double glazing. Our supply-only prices start from £92.42 + VAT, saving you 40-60% even after hiring your own local FENSA-registered installer (typically £150-250 per window).
Example: Full House Double Glazing Replacement
(3-bedroom house requiring 10 windows)
WSD Supply-Only
10 casement double glazed windows = £1,398.70 + VAT
Local Installer
£150 × 10 windows = £1,500
£2,898.70
What's Included in Our Prices?
- Made-to-measure manufacturing to your exact sizes
- 70mm UPVC profile system (Eurocell, Rehau, or Veka)
- 28mm sealed glass units with argon gas filling
- A+ energy rating with U-values as low as 1.2 W/m²K
- Multi-point locking systems on all opening windows
- Trickle vents fitted as standard (Building Regulations compliant)
- Premium hardware in white, gold, chrome, or black finish
- 10-year manufacturer guarantee
- VAT included at checkout
Energy Efficiency Of UPVC Double Glazing
How Energy Efficient Are Double Glazed Windows?
Modern UPVC double glazing windows from Window Supply Direct achieve A+ energy ratings with U-values as low as 1.2 W/m²K—well exceeding the UK Building Regulations requirement of 1.4 W/m²K for replacement windows.
Understanding U-Values:
- Single glazing: 5.0-5.8 W/m²K (non-compliant)
- Old double glazing (pre-2002): 2.8-3.0 W/m²K
- Modern double glazing: 1.2-1.6 W/m²K (our standard)
- Triple glazing: 0.8-1.0 W/m²K
Our 28mm sealed glass units with low-E coating and argon gas filling deliver exceptional thermal performance that could reduce your heating bills by 15-20% annually compared to old double glazing.
Annual Energy Savings:
For a typical 3-bedroom semi-detached house replacing old double glazed windows:
- Old double glazing (U-value 2.8): Annual heating cost £1,200
- New A+ double glazing (U-value 1.2): Annual heating cost £960-1,000
- Annual savings: £200-240
- Payback period: 12-15 years based on window replacement cost
Double glazing also significantly improves home comfort by eliminating cold spots near windows, reducing condensation, and maintaining more consistent room temperatures throughout the year.