Draught-Proof Your Windows: Thermal Secondary Glazing London
Dramatically improve your home's energy efficiency with secondary glazing. Reduce heat loss, eliminate draughts, and lower your heating bills while preserving your original windows.
The Hidden Cost of Inefficient Windows
Windows can account for up to 40% of a home's total heat loss through single-glazed windows. Single-glazed and older double-glazed windows are particularly inefficient, allowing precious warmth to escape and cold draughts to enter. This translates directly to higher energy bills and reduced comfort—our secondary glazing U-value performance guide explains exactly how secondary glazing reaches 1.8 W/m²K, and the secondary glazing ROI and payback calculator shows your 3–5 year payback.
Secondary glazing creates an insulating air gap between your existing window and the new internal panel. This trapped air acts as a thermal barrier, dramatically reducing heat transfer. The result is a warmer home that requires less heating to maintain comfortable temperatures.
Unlike replacement windows, secondary glazing works with your existing frames, making it ideal for period properties, listed buildings, and conservation areas. You get the thermal benefits of modern glazing while preserving your property's original character.
Our thermal insulation solutions can reduce heat loss by up to 65% and eliminate 100% of draughts. Combined with our noise reduction benefits, secondary glazing offers a comprehensive upgrade to your living environment.
Thermal Benefits
Transform your home's energy performance
Up to 30% Energy Savings
Significantly reduce heat loss through windows, lowering your heating bills.
Improved U-Values
Achieve U-values as low as 1.8 W/m²K, approaching double glazing performance.
Condensation Prevention
Eliminate condensation on original windows by creating a warmer inner surface.
Reduced Carbon Footprint
Lower energy consumption means reduced CO2 emissions from your home.
Energy Savings
Typical savings for a London home with secondary glazing
Understanding U-Values
U-value measures thermal transmittance—lower is better
Secondary glazing brings single-glazed windows close to modern double glazing performance
How It Works
Our thermal insulation process
Thermal Assessment
We evaluate your current windows and identify heat loss areas.
Solution Design
Custom secondary glazing designed to maximise thermal performance.
Expert Installation
Precise fitting ensures optimal air gap and thermal efficiency.
Performance Verification
We verify draught elimination and improved comfort.
Thermal Glazing Pricing
Thermal secondary glazing starts from £450 per window, subject to survey. Energy savings vary with the original windows, building fabric, heating use and installation.
Including survey, design, and installation
- Free thermal assessment
- Energy savings estimate
- 10-year warranty
- Condensation prevention
Energy Efficiency Resources
Learn more about thermal performance
EPC & Thermal Efficiency
Cut heating bills by 30%
Thermal Performance Guide
U-values and energy savings
Energy Savings Calculator
Estimate your savings
ROI Calculator
Calculate your payback period
Related Services
Cut Your Heating Bills by 30% This Winter
Book a free thermal audit — we'll calculate your exact savings and payback period before you commit.
Thermal benefits, energy costs & condensation guides
Deepen your research with our specialist resources — each link goes to a single, focused article so you can compare specifications, benefits and pricing in detail.
- Thermal, acoustic and condensation benefits of secondary glazing
Reduced heat loss through single-glazed sashes — the data behind the claim.
- Energy savings calculator for London homes
Estimate annual heating cost reduction by window count, glass spec and current single-glazed baseline.
- Secondary glazing ROI & payback calculator
Payback period across typical 3–12 window homes including the heritage-grade specifications.
- Cost & pricing guide for thermally-optimised installations
Low-E glass, warm-edge cavity and frame upgrade pricing explained line by line.
- Why the same air gap that cuts noise also cuts heat loss
The shared physics of acoustic and thermal performance in secondary glazing systems.
- Acoustic 10.8mm laminate — a dual acoustic + thermal upgrade
How laminate glass improves both U-value and Rw in one specification.
Frequently Asked Questions
Long-tail answers on U-values, heating bill savings, EPC ratings and condensation control for London homes.