Double Glazing Installers London & Surrey | Window Fitters Lt

Energy-Efficient Double Glazing Supply & Installation

Replacing old, single-pane glass or failing double-glazed windows is the single most effective way to improve your home's thermal insulation, security, and noise protection. At Window Fitters Ltd, we combine over 10 years of experience in the glazing trade to deliver high-performance double glazing installations for residential homes, refurbishments, and commercial properties across London, Surrey, and surrounding areas (within a 40-mile radius).

Our directly employed, skilled fitting team handles every project from the initial measurement survey to final sealing, and we never outsource to third-party sub-contractors.

How Modern Double Glazing Works

Older double glazing was prone to condensation and heat leaks. Our modern double-glazed sealed units are engineered using advanced materials to maximise performance:

• Low-E Glass Coatings: The inner pane features a microscopically thin metal oxide coating. This allows natural sunlight to enter while reflecting indoor thermal heat back into your living space.
• Argon Gas Fills: The cavity between the two glass panes is hermetically sealed and filled with Argon gas, which is denser than air and acts as an invisible barrier to slow down heat transfer.
• Warm-Edge Spacer Bars: Traditional units used cold-conducting aluminium spacer bars. We use non-metal, structural foam spacers to prevent thermal bridging and condensation around the perimeter of the glass.
• UK Document L Compliance: Our double-glazed systems typically achieve a whole-window U-value (Uw) of around 1.2 to 1.4 W/m²K. This easily meets UK Building Regulations Document L requirements for window replacements (1.4 W/m²K maximum) and aligns with new build targets (1.2 W/m²K). We can source any profile system on the market-including uPVC, aluminium, and high-performance timber/alu-clad frames-prioritising proven thermal quality, structural rigidity, and long-term durability.

Key Benefits of Our Glazing Services

• Reduced Energy Bills: By trapping warmth inside, double glazing reduces the demand on your central heating, lowering your utility costs.
• Acoustic Soundproofing: The dual-pane structure dampens sound waves, significantly reducing street noise, traffic, and aircraft disturbances.
• Enhanced Home Security: Fitted with tough safety glass (Document K compliant) and secured within PAS 24 / Secured By Design certified frames with multi-point locking systems to prevent forced entry. All ground-floor and accessible windows meet Document Q requirements.

Our Double Glazing Solutions

We provide comprehensive solutions tailored to your property's requirements:

• New Window Fittings: Custom uPVC casements from leading profile systems (including Deceuninck 2500, Liniar Sculptured, Rehau T70C, and Profile 22 Optima), sliding sash windows, and slimline aluminium frames. Check our full window installation and uPVC windows services.
• New Door Fittings: High-security composite entrance doors, double-glazed French doors, and matching aluminium bifold systems. See our door installation packages.
• Misted Unit Glass Swaps: If you have condensation inside your double glazing (foggy glass), you do not need to replace the entire window. We can swap just the failed glass unit, saving you substantial money. Learn about our double glazing repairs.

Flexible Contracts & Trade Pricing

We offer full flexibility on all projects. You can opt for a comprehensive Supply and Fit contract, or choose our Installation Only service if you have already purchased your own windows. We also work directly with you to help you source high-quality glass, frames, and Door Hardware & Security Locks at discounted trade prices. For example, we can help you find manufacturers offering energy-efficient double glazing at trade rates.

All work is fully insured with our £5,000,000 public liability policy and backed by a 5-year frame and glass guarantee. Every installation includes trickle vents (Document F), toughened safety glass in critical zones (Document K), and PAS 24 security hardware as standard. Our typical lead time for standard double glazing projects is 2 to 3 weeks from confirmed order.

Ready to get started? Use our interactive Window & Door Survey Designer to upload your drawings and prepare your measurements online, or contact us today to book a free home survey.

About the Author: Marian Gheorghe

Head Window Fitter & Active Director, Window Fitters Ltd

Marian Gheorghe is the Head Window Fitter and Active Director of Window Fitters Ltd. With over 15 years of hands-on experience in the glazing and glazing industry across London, Marian leads the direct-employment labour force and oversees technical safety compliance for all residential and commercial JCT contracts. He ensures every installation conforms to British Standards and UK Building Regulations.

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