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Benefits of Double-Glazed Sash Windows

The benefits of having double glazed windows in your home is huge both thermally and acoustically. Around 25% of the heat loss in an average property is through the windows and doors, so by simply having new windows and doors fitted you can dramatically improve the energy efficiency and EPC rating of your property. 

At SWL our mission is to create high performing windows which replicate the profiles Traditionally used across London properties.  

All of our windows exceed current building regulations with a range of solutions offering U Values as low as 1.2W/m2K.

Double Glazed Box Sash Windows

Box sash windows are a beautiful addition to any property. The box sash windows we sell and install at Sash Windows London Ltd are specifically designed to ensure they mimic the traditional sash window as closely as possible. Choose from traditional double glazed timber sash windows or double glazed UPVC sash widows, the choice is yours. At Sash Windows London Ltd, we cater to your requirements. So, if you’re looking for box sash windows double glazed, contact us today.

Double Glazed Sash Windows UK

If you’ve experienced draughts from your sash windows, rattling sounds, or condensation build-up, you need replacement sash windows double glazed. Don’t suffer through another cold winter with single glazing, it’s not worth the stress and it’s definitely not worth the high energy bill price!

At Sash Windows London Ltd, we double glaze all of our windows to ensure optimum comfort levels in your home all year round. With double glazed sliding sash windows, it doesn’t matter what the weather is doing outside because our double glazing has you covered. We can even offer triple glazing to reduce outside noise and heat loss even futher.

Double Glazed Timber Sash Windows

If you want authentic and high-quality double glazed timber sash windows, you’ve come to the right place. Timber has been used as a building material for hundreds of years. It is well-known for its functionality, pleasing aesthetics, and durability.

The timber sash windows we sell and install are all double glazed, long-lasting, and energy efficient. What’s more, we protect all our timber sash windows from rot, decay, and weathering. Our wooden sash windows are definitely for you! If you would like to find out our double glazed timber sash windows cost, please do not hesitate to get in touch with our team today. We would be more than happy to answer any questions you may have!

UPVC Double Glazed Sash Windows

Here at Sash Windows London Ltd, we are passionate about making our products available to everyone. That’s why we work hard to provide affordable sash window materials, like UPVC.

Our double glazed UPVC sash windows are made to mimic the look, style, and quality of timber as much as possible. Our UPVC windows are some of our most affordable products and provide quality, durability, and security for all our customers – making them a popular choice. If you would like to discuss UPVC double glazed sash windows price, please do not hesitate to get in touch with our team today.

How Double Glazing Works

Our glazing units are built to the highest standards using the best quality products. The most efficient type of glass for double glazing is low emissivity (Low-E) glass. Low-E glass contains a special coating of metal oxide which is invisible and lets in light, but is excellent at preventing heat from escaping. This is used in conjunction with spacing between each pane of glass which can be filled with different types of gas. The gas is used for replacing dehydrated air in the gaps and has a much lower thermal conductivity than air. There are different types of gas such as argon, xenon or krypton, and argon in particular has a 34% lower thermal conductivity, so is extremely effective when it comes to preventing heat loss.

The pane spacers themselves, which are used to separate the glass are warm edge spacers and contain very little metal. We’ve found these to be the most energy efficient and can really maximise the amount of heat kept inside your property.

Double Glazed Sash Windows Cost

The cost of double-glazed sash windows can vary depending on the materials, size and quantity. For example, wooden double glazed sash windows may be more expensive than uPVC or aluminium. Here at Sash Windows London Ltd we constantly strive to keep our prices at a minimum, so give us a call today to discuss your requirements.

We Protect Your Property’s Heritage

When installing double-glazed sash windows for listed buildings, we will work to install a window that fits seamlessly with your property’s design. If you live in a heritage property, we provide double-glazed sash windows in grade 2 listed buildings and other period properties.
We know that maintaining the look and style of your home is extremely important, and that’s why we work hard to provide windows that complement your property’s heritage. We are the window company for you if you want a double-glazed sash window conservation area.
At Sash Windows London Ltd, we share your passion for preserving the original heritage of your home. Whether your property is a heritage building, located in a conservation area, or boasts traditional detailing, we are dedicated to finding the perfect windows that uphold its unique

Our Double Glazed Sash Windows Price List

Here at Sash Windows London Ltd, our double glazed sash window price list is quite straight forward; windows will be more expensive the bigger and more elaborate they are. Our double glazed UPVC sash windows cost depends on the size and number of windows you want to have installed. This is the same for timber materials and the style of window you are opting for. If you would like to discuss window cost, please do not hesitate to get in contact with us today. We would be more than happy to discuss your requirements.


  • 10 years on PVCU
  • 30 years on timber
  • 10 years on glazing
  • 5 years ironmongery and seals

Benefits of Double Glazing

  • Lower energy bills
  • Less carbon footprint
  • More comfortable home: energy efficient glazing reduces heat
  • Peace and quiet: as well as keeping the heat in, energy efficient