Factors Affecting Cost
Several factors influence the final price of your secondary glazing project:
1. Window Size
Larger windows require more materials and are more complex to manufacture and install. Price typically increases proportionally with size, though per-square-metre cost decreases for very large windows.
2. Opening Mechanism
Fixed/Lift-out
Most economical option
Horizontal Sliding
Mid-range price
Vertical Sliding
Higher cost (sash-style)
Hinged Casement
Premium option
3. Glass Type
| Glass Type | Use Case | Price Impact |
|---|---|---|
| 4mm Float | Thermal only | Baseline |
| 6mm Float | Standard acoustic | +10-15% |
| 6.4mm Laminated | Premium acoustic | +25-35% |
| 10.8mm Laminated | Maximum acoustic | +45-60% |
4. Frame Finish
Standard white frames are included in base price. Other finishes have varying costs:
- • Standard White: Included
- • Brown/Black: +£20-30 per window
- • Custom RAL colour: +£50-80 per window
- • Wood grain effect: +£40-60 per window
5. Installation Complexity
Additional costs may apply for:
- • Difficult access (scaffolding, high windows)
- • Unusual window shapes (arched, circular)
- • Stone reveals requiring special fixings
- • Listed building requirements
Example Project Costs
2-Bed Victorian Flat
Hackney, London
£3,200
- • 6 sash windows (horizontal sliding secondary)
- • 6.4mm laminated acoustic glass
- • White powder-coated frames
- • Traffic noise reduction focus
3-Bed Semi-Detached
Richmond, Surrey
£5,800
- • 8 windows including 1 bay window
- • Mix of casement and sliding panels
- • 6mm float glass
- • Thermal and acoustic improvement
Grade II Listed Townhouse
Chelsea, London
£12,500
- • 12 large sash windows over 3 floors
- • Vertical sliding (heritage-style)
- • Slim profiles for minimal visual impact
- • 10.8mm laminated acoustic glass
Return on Investment
Secondary glazing isn't just an expense - it's an investment that pays back through energy savings and property value.
Energy Savings
- • Typical annual saving: £150-400
- • Heat loss reduction: up to 65%
- • Payback period: 5-8 years
Property Value
- • Adds to EPC rating
- • Attractive to noise-conscious buyers
- • Preserves character (listed properties)
ROI Insight: A typical £4,000 installation in London can add £8,000-15,000 to property value while saving £200+ annually on heating - delivering both immediate comfort and long-term financial returns.
Secondary vs Double Glazing Costs
| Cost Factor | Secondary Glazing | Double Glazing Replacement |
|---|---|---|
| Average per window | £400-800 | £800-1,500 |
| Typical whole house | £3,000-8,000 | £7,000-15,000 |
| Installation time | 1-2 days | 3-5 days |
| Disruption level | Minimal | Significant |
| Listed building suitable | Yes | Usually no |
Payment Options
Standard Payment Terms
- 50% deposit on order confirmation
- 50% balance on completion
- All major cards accepted
Finance Available
- 0% interest over 12 months (subject to status)
- Spread cost over 24-60 months
- Quick online application
Related Resources
EPC & Thermal Efficiency Guide
How secondary glazing cuts heating bills by 30% and improves your EPC rating.
ROI Calculator
Calculate your return on investment from energy savings and property value increase.
Energy Savings Estimator
Estimate your annual energy savings with secondary glazing.
Secondary Glazing vs Double Glazing
Compare costs, performance, and suitability for your property.
Get Your Personalised Quote
Every project is unique. Get an accurate quote based on your specific windows and requirements.