Fixed Secondary Glazing | Maximum Performance, Lowest Cost
Fixed secondary glazing offers London homeowners the ultimate combination of maximum thermal and acoustic performance at the lowest cost. Providing maximum performance for preserving original Victorian, Georgian, and Edwardian windows. Perfect for properties with never-opened windows, extreme noise environments, and budget-conscious homeowners seeking the best value. Ideal for listed buildings and conservation areas, fixed units deliver superior results without the complexity of opening mechanisms.
£250-£550
Per Window
60-70%
Heat Loss Reduction
75-85%
Noise Reduction
25-30
Years Lifespan
What is Fixed Secondary Glazing?
Fixed secondary glazing consists of permanently sealed glass units installed 50-100mm in front of your existing windows. Unlike hinged or lift-out alternatives, these units have no opening mechanism – they're simply screwed into your window reveal and sealed around the perimeter for maximum performance.
Key Differences from Other Types:
- FixedPermanently sealed, no opening mechanism, occasional screw removal for access (£250-£550 per window)
- HingedOpens on hinges like a door for regular access (£400-£700 per window)
- Lift-outCompletely removable with clips for seasonal access (£300-£500 per window)
The main trade-off is simple: access convenience versus performance and cost. Fixed glazing delivers maximum thermal and acoustic benefits at the lowest price, while sacrificing easy access to the primary window behind.
When to Choose Fixed Over Hinged Options
Fixed secondary glazing excels in specific situations where access isn't a priority but performance and cost-effectiveness are paramount.
Never-Opened Windows
Perfect for Victorian and Georgian properties where upper floor windows are painted shut after decades of use. These windows were never intended for regular operation, making fixed glazing an ideal match. Similarly effective for decorative windows in stairwells, hallways, or windows blocked by furniture like bed heads or built-in wardrobes.
Extreme Noise Environments
London's challenging acoustic environment makes fixed glazing particularly valuable. Properties under Heathrow flight paths experiencing 70-80+ dB aircraft noise every few minutes benefit from the continuous sealed perimeter. Major roads like the North and South Circular, A-roads, and railway lines create constant noise that fixed glazing addresses with up to 75% noise reduction through its superior sealing.
Budget-Conscious Maximum Performance
When you need the best thermal and acoustic results at the lowest cost, fixed units deliver 60-70% heat loss reduction compared to 50-60% from hinged alternatives. The 20-40% cost savings per window multiply significantly across whole properties – a typical 12-window installation saves £1,200-£2,400 compared to hinged units.
Listed Building Requirements
Grade II listed properties benefit from fixed glazing's minimal intervention approach. Conservation officers prefer the simplicity of permanently sealed units with no moving parts, viewing them as a clean, traditional solution that protects original windows indefinitely.
Cost and Value Proposition
Fixed secondary glazing represents exceptional value in London's expensive property market:
Per Window Costs:
Typical Property Savings:
- 12 windows: Save £1,200-£2,400 choosing fixed over hinged
- 20 windows: Save £2,000-£4,000 on larger properties
The lower cost stems from simpler manufacturing – no hinges, handles, or alignment mechanisms. Installation is faster at 30-60 minutes per window versus 60-90 minutes for hinged units, reducing labour costs further.
Access and Cleaning Made Simple
The biggest concern about fixed glazing is access for cleaning and maintenance. In practice, this proves far simpler than expected:
Exterior Cleaning
Remains unchanged – your existing method (professional cleaners, ladders) works exactly as before since secondary glazing is fitted internally.
Interior Surface
Routine cleaning – simply wipe the glass like any window.
Between-Panes Access
Requires removing 4-8 screws around the frame, lifting out the panel, cleaning both surfaces, and replacing – typically taking 5-10 minutes once or twice yearly.
Most homeowners discover they rarely need this access. Upper floors are cleaned externally by professionals anyway, while sealed spaces between panes stay remarkably clean with minimal dust ingress.
Maximum Performance Benefits
Fixed secondary glazing's continuous sealed perimeter delivers measurable advantages over alternatives with opening mechanisms. Understanding optimal air gap spacing for fixed units maximises these benefits.
Best Thermal Insulation Results
Superior thermal performance - the uninterrupted seal eliminates air leakage that reduces other systems' effectiveness. U-values improve from typically 2.0-3.0 W/m²K to 1.0-1.5 W/m²K – essentially transforming single-glazed windows to near-modern double glazing performance.
Annual energy savings of £600-£1,200 are common on properties with significant glass areas, creating payback periods of 2.5-4 years.
Highest Acoustic Performance
Achieves the highest acoustic performance of all secondary glazing types. That same continuous seal prevents sound leakage that compromises hinged units at hinge points. Learn about sound transmission in fixed units for detailed specifications.
Combined with heavy acoustic glass (10.8-12.8mm), total noise reductions of 75-85% transform unbearable environments into comfortable living spaces.
Complete Condensation Control
The sealed perimeter provides complete condensation control by keeping the inner glass surface consistently warmer, eliminating moisture buildup that can damage original window frames and cause mould growth.
Maximum Security
Maximum security when permanently fixed - no opening mechanisms to compromise, creating an impenetrable additional barrier with laminated glass options that hold together when attacked.
Reliability and Longevity
No moving parts means nothing to adjust, lubricate, or replace. Fixed units typically last 25-30 years versus 20-25 years for hinged alternatives where mechanical components eventually wear. This translates to lower long-term costs and maintenance hassles.
Ideal Applications in London
Flight Path Properties
Properties under Heathrow, Gatwick, and City Airport approach paths experience peak aircraft noise of 70-80+ dB every few minutes. These windows are never opened due to noise levels, making fixed glazing with heavy acoustic glass the logical choice for 85%+ noise reduction.
Major Transport Routes
Victorian terraces along the North Circular, South Circular, and major A-roads face constant 70-75 dB traffic noise. The uninterrupted acoustic barrier of fixed glazing paired with 8.8-10.8mm acoustic glass reduces this to tolerable background levels.
Railway Corridors
Properties near Overground lines, mainline railways, and tube surface sections deal with both noise and vibration. Fixed glazing with heavy glass dampens both effectively, particularly important where trains pass every few minutes throughout the day.
Period Property Upper Floors
Georgian and Victorian properties commonly have painted-shut upper floor windows that haven't opened in decades. Fixed glazing maximizes thermal performance where heat loss is greatest while preserving the building's character with minimal intervention.
Glass Specifications Guide
Choosing appropriate glass thickness depends on your specific noise environment and budget. Read our complete cost guide for detailed pricing information:
4mm standard
Quiet residential areas, budget priority
£250-£350 per window
6.4mm acoustic
Suburban areas with moderate traffic
£300-£400 per window
8.8mm medium performance
Busy urban streets and A-roads
£400-£500 per window
10.8mm high performance
RecommendedCity centers, railways, flight paths
£450-£550 per window
12.8mm premium
Maximum flight path noise, extreme environments
£500-£650 per window
For flight path properties: 10.8mm represents the minimum recommendation, with 12.8mm providing ultimate protection for properties directly under approach paths.
Installation Process
Fixed secondary glazing installation follows a streamlined 7-step process:
Consultation
Assess suitability for fixed versus hinged options based on window usage patterns
Survey
Precise measurements and primary window condition assessment
Specification
Glass selection and frame color matching to interior aesthetics
Manufacturing
Custom frames built to exact dimensions (4-6 week lead time)
Installation
Professional fitting in 30-60 minutes per window
Quality Assurance
Seal verification and access demonstration
Aftercare
Comprehensive warranty and ongoing support
The faster installation compared to hinged units means less disruption – a typical 12-window property completes in one long day rather than requiring multiple visits.
Performance Comparison
| Feature | Fixed | Hinged | Lift-out |
|---|---|---|---|
| Cost per window | £250-£550 | £400-£700 | £300-£500 |
| Thermal performance | 60-70% reduction | 50-60% reduction | 50-60% reduction |
| Acoustic performance | 75-85% reduction | 70-80% reduction | 70-75% reduction |
| Installation time | 30-60 minutes | 60-90 minutes | 45-75 minutes |
| Maintenance | Minimal | Moderate | Low |
| Access to primary | Screw removal | Easy opening | Complete removal |
| Best applications | Never-opened, extreme noise, budget | Regular access needed | Seasonal access |
Frequently Asked Questions
Fixed secondary glazing represents the optimal choice for London properties prioritizing maximum performance and value over routine access convenience. When your windows are never opened anyway, why pay extra for opening mechanisms you'll never use?
Ready to Transform Your Property?
Contact us for a free consultation to assess your specific needs and discover potential savings with fixed secondary glazing.