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Timber Sash Windows

Wooden Sash Windows - Double-Glazed Windows

Timber sash windows which are double-glazed are a popular choice for homeowners who want to improve the energy efficiency of their homes. Double-glazing works by trapping a layer of air between two panes of glass, which helps to insulate the home and keep heat in during the winter and cool air in during the summer.

LBS is a London-based company that has been manufacturing sash windows for over 40 years. We offer a wide range of double-glazed sash windows to suit every home. Our windows are made from the finest timber and are fitted to the highest standards.

We are a family-run business, and we are passionate about providing our customers with the best possible service. We are always listening to our customers’ feedback, and we are constantly innovating to improve our products and services. Find out more below

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Timber Sash Windows

Accoya wood used for our timber sash windows

Accoya Wood


Known for its exceptional durability and stability. Resistant to rot, decay, and insects, Accoya wood is also a sustainable choice with low environmental impact. Made from non-toxic, sustainably sourced materials and with a very long lifespan, Accoya wood is the perfect choice for windows and doors

Double-Glazed unit. Used in the construction of our timber sash windows

Glass & Glazing

At London Box Sash Windows, we take pride in crafting only the finest double-glazed units. Made in house, ensuring the highest level of quality and performance in every unit we produce

Timber sash window spray finished in Teknos paint



Sash windows, finished with the latest low-maintenance paint systems and state-of-the-art drying technology for a flawless, long-lasting finish.

Sash Windows
At London Box Sash Windows, we have been perfecting the design of our sash windows for over 40 years, continuously making improvements to both the aesthetic and performance aspects. We are proud to offer a product that has been honed and refined through years of research and development, ensuring that our customers receive the highest quality and most advanced sash windows on the market.
Casement Windows
At London Box Sash Windows, we've honed our expertise in bespoke casement windows through years of customer collaboration and technological advancements. Our windows are among the most high-performing on the market, offering unbeatable thermal efficiency. Yet, we remain dedicated to preserving the classic heritage of the casement window design. That's why our range features precise, flush-line finishes that add character to your property. Whether you're looking for traditional or modern designs, we have bespoke casement window options to fit your unique needs.
French Doors
Experience authentic style with our handcrafted timber French doors. Choose from traditional or contemporary designs, tailored to your exact specifications. Our doors feature double-glazing to A-rated specs and advanced microporous paint for ultimate insulation and durability. Trust in our expert installation for a fully completed and high-performing door solution.

Extreme Stability

70% to 80% reduction in swelling & shrinkage

Low Maintenance

Paint finish that lasts 3-4 times longer

Robust Construction

Mortice & tenon joints used


Traditional features sympathetically replicated

High Performance

A-rated double-glazed units

Naturally Insulating

Improved thermal insulation

One Wood Sash Window - One Tree Planted

We are passionate about sustainability and protecting the environment. We believe that everyone has a role to play in creating a healthier planet, and we are committed to doing our part.

That’s why we only use FSC timber for our timber sash windows. Not only is this more sustainable, but it also means that our windows are of the highest quality. We also support One Tree Planted, a charity that plants trees around the world. For every sash window we sell, we plant a tree.

We believe that by working together, we can make a difference. If you are looking for a sustainable and stylish way to improve your home, then consider our timber sash windows. You can be sure that you are making a positive impact on the environment.

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When looking into window options, there are several reasons why you might choose Timber Sash windows.

Here are some key advantages:

Energy Efficiency:

Timber Sash windows can be manufactured with modern materials and techniques that enhance their energy efficiency. Double glazing, weatherstripping, and insulated frames are available options, which can help reduce heat loss, improve insulation, and contribute to lower energy bills.

Noise Reduction:

Living in a bustling city like London often means dealing with external noise. Timber Sash windows, especially when combined with double glazing, can provide effective noise reduction, creating a quieter and more peaceful living space.

Smooth Operation:

High-quality London Box Sash windows are designed to operate smoothly and effortlessly. They typically incorporate counterbalanced mechanisms or spring systems, allowing for easy opening and closing without the need for excessive force or maintenance.T

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