Leading company for sash windows Lewisham

A-rated sash windows and Accoya sash windows for energy saving and aesthetics in Lewisham, Hither Green, or nearby areas

London Box Sash Windows is a local, trusted, family-run business with over four decades of experience providing top-quality timber sash and casement windows throughout the London area. Every project is executed with care, ensuring your satisfaction at every step.

We specialise in crafting and installing traditional timber sash and casement windows. We prioritise energy efficiency while maintaining your property’s architectural charm and kerb appeal. Our windows are made from Accoya wood, which is also energy efficient and will save you money on fuel bills.

From designing and crafting bespoke sash windows to expert installation and ongoing replacement services, our specialists handle every aspect of your sash window needs. With a commitment to quality and attention to detail, London Box Sash Windows ensures your home retains its character while benefiting from modern efficiency and craftsmanship you can rely on.

Our dedicated and skilled team takes pride in delivering a helpful, reliable, and professional service you can trust. Whether installing new sash windows or replacing existing ones, we offer customised solutions tailored to your needs at competitive prices.

We take great pride in our trusted relationships with our clients. One recent customer said:

I recently had a new sash window fitted in my living room, and London Box Sash could not have been more helpful. Jake was absolutely brilliant and talked me through all the options and helped me choose what was right for me. The ordering process was simple and the fitting was carried out in one day and I am so happy with the finish. Would definitely recommend – the care and attention to detail is wonderful. Thank you!

Get a sash window quote now by calling 020 8648 4230.

Hither Green Exceptional replacement sliding sash windows & box sash windows installed near you

At London Box Sash Windows, each product is made to order and installed by our in-house specialists. To ensure your satisfaction, all sash window and casement window installations come with a full guarantee, giving you confidence in the durability and quality of our work.

We provide personalised, detailed quotations for every project and are always available to answer your questions. All replacement box sash windows are custom-made and handcrafted, ensuring an authentic and precise reproduction tailored to your home’s needs.

For examples of our recent sash window installations, explore our portfolio.

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Why opt for Accoya sliding sash windows in Lewisham, SE13

Lewisham in South East London is known for its diverse mix of architectural styles. The area features Victorian and Edwardian terraced houses with ornate sash windows and post-war housing developments that add to its varied character. Modern apartment complexes and regenerated spaces are becoming increasingly common, blending contemporary design with the area’s historic charm. Our sliding sash windows can be designed to match properties of all styles and descriptions.

Accoya wood is an engineered timber treated with a patented acetylation process. This process enhances its natural properties to deliver exceptional durability, stability, and resistance to decay. These features make it ideal for modern replica replacement sash windows, blending traditional aesthetics with advanced performance.

Accoya’s durability ensures a lifespan of over 50 years above ground, far surpassing untreated timber and many hardwoods. This makes it highly reliable for external applications. Its dimensional stability prevents swelling, shrinking, or warping.

Accoya’s excellent thermal efficiency improves insulation, reducing energy loss and heating costs. Sourced from FSC®-certified forests and 100% recyclable, Accoya is an eco-friendly choice for sustainability-focused homeowners.

Please see our blog: Maintaining sash windows: Tips for London homeowners.

Lewisham sash window installation: What makes our company special?

Since 1980, London Box Sash Windows has crafted high-quality sash windows that are close to our customers. By installing 95 per cent of our windows within 10 miles of our London workshop, we minimise our environmental impact, reduce carbon emissions, and support local businesses and communities.

Our London workshop specialises in restoring, repairing, and creating sash windows, blending timeless elegance with modern functionality. Located centrally, it serves as a hub for homeowners, professionals, and sash window enthusiasts, offering expert craftsmanship and personalised service to preserve the charm and character of every property.

Aalia Khan

London Box Sash have done a fantastic job. I’ve now used their services around four times, and on each occasion I’ve compared options—yet they consistently stand out as the best by far, offering a great balance of competitive pricing, excellent service, and beautifully crafted products.

Firstly, their windows are stunning, with a wide range of hardware options. I’ve had both sash and casement windows installed, all made from high-quality Accoya wood, which really shows in the finish.

Secondly, the installation team are excellent. They take real care to make good around the windows—whether that’s repainting walls or fixing tiles—so nothing looks unfinished. They’re punctual, respectful of your home, and work efficiently and professionally, often completing installations within half a day.

Thirdly, the entire process—from ordering to survey to installation—is smooth and well-managed. The team feels consistent and personal, with people like Judith handling bookings and payments, and Harry and Jake carrying out surveys. It has the feel of a trusted family business, with knowledgeable staff always on hand to offer helpful advice on the best options.

Lastly, their aftercare is outstanding. Even with more complex installations (my Victorian walls weren’t the easiest!), they are quick to problem-solve and always willing to return promptly if needed.

Overall, I wouldn’t hesitate to recommend London Box Sash.

Christopher Wylde

Very happy with the whole experience here from start to finish. Professional and honest outfit that will do excellent work. Very happy to take on bespoke needs so if you have something slightly different to standard requirements these are the people to go for!

UPDATE: used these guys again for my new house. Nothing has changed: still an excellent service. Nothing is too much trouble, great experience from start to finish. Great aftercare tips upon request. Nothing is too much trouble. You definitely get what you pay for with these guys.

Tracy Clark

Simply outstanding! Everyone we dealt with was super friendly, polite and very efficient. The installation was seamless and they covered everything up with dust sheets and plastic. The windows are stunning and so easy to open. I highly recommend them.

gervase

We recently had our sash windows installed by London Box Sash Windows, and the whole experience was excellent.

Anjelo and Raf, the installation team were respectful, professional, and did a wonderful job. Jake who looked after us on the sales side, was helpful and knowledgeable, Judith kept it all organised.

The sash windows themselves look absolutely beautiful and have completely transformed the appearance of the house. We’ve had a number of compliments from people passing by, which speaks for itself.

Brad V

You do not need to worry because this company make, supply and fit the best windows around.
I have used them well over 10 years on various projects and i would not go elsewhere. What can i say other than ‘superb in every respect’
Their choice of wood and paint is astonishing as they never move or crack and look like they were fitted only yesterday even though my original windows from them are well over 10 years old, i have never had to do anything to them.
I cannot express how brilliant their products are and, their service is fantastic. I would never use any other supplier.

Phil Bowen

We have used London Box Sash Windows twice in the past four years. We can’t speak highly enough of the customer service, the ease of the sales process, the quality of the work and the professionalism of the window fitter. We now have a beautiful set of windows in our house and would not hesitate to recommend them.

Helen Jenkins

I found London Box through Which Trusted Traders and was so glad that we chose them to replace a bathroom window in 2025 following it being damaged through an attempted break-in. We were so impressed with the service given by the company through the assessment visit by Simon, the contact and support through the office of the lovely Judith and the amazing work done in a single day by the wonderful Andy to replace the window. He worked tirelessly all day and cleaned and tidied up beautifully afterwards. Because of their impressive service installing this window we employed them to replace the bay windows on our house which was a much bigger and more complicated job because of issues to do with the state of the bay itself but London Box were more than up to it. This time Harry came to measure up and Judith in the office continued to keep us informed and up to date with the process. Angelo and Raf did a fantastic job on the day installing the new windows. It was a very difficult job but they did amazingly well and we couldn’t be happier with the windows as well as with every aspect of our involvement with the company. Would throughly recommend this company and not hesitate to use them again in future.

Andrea Melville

I have used London box sash windows three times. The product stands the test of time. We had upstairs bedroom windows installed in 2014. Lounge in 2021 and bathrooms 2026. They open as easily today as when installed. Service is professional. Everything left clean. When some water got in some glass it was replaced quickly with no fuss. A great experience and a great product.

Book a sash window survey in any of the nearby locations:-

Cubitt Town
Deptford
Forest Hill
Greenwich
Kidbrooke
Lewisham
Millwall
New Cross
Poplar
Shooters Hill

Would you like a sash windows consultation in Lewisham? Call now

Our sash windows team is here to take your call. Please call 020 8648 4230 or email info@londonboxsash.com.

Do you need sash windows Kingston? Call our local specialists today.