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Bespoke sash windows in Forest Hill

Replacement sash windows and wooden sliding sash windows installed in Forest Hill, Sydenham and nearby areas

Sash Windows Installed on Piermont Road, SE22
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Installing Sash Windows In Forest Hill since 1980!

London Box Sash Windows is your go-to local expert for sash and replacement sash windows. We specialise in crafting bespoke sash windows using premium Accoya wood and A-rated double glazing. Our sash windows blend traditional elegance with modern energy efficiency and long-lasting durability.

Accoya wood, known for its sustainability and resistance to rot, decay, and warping, is the ideal material for sash windows. Combined with high-performance double glazing, our box sash windows offer outstanding insulation, helping to lower energy bills while maintaining timeless charm.

Our sash window team is highly rated on Google reviews and has received top feedback on Which? Trusted Traders, where we have been members since 2011.

One recent customer said:

Very efficient local team, first to book appointment and good contact from Judith in the office. Very thorough presentation from Jake and ability to offer a discount for speedy installation. Andy installed windows and he was professional & friendly. A very clean and methodical approach. They also have an after service care should anything happen which is very reassuring .I have already recommended them to two friends of mine.

All our sash window products are made locally at our London factory near Wimbledon, with 90 per cent of installations within eight miles of production, supporting the community and reducing our environmental impact.

Visit our showroom to explore our sash windows and get expert advice from our knowledgeable team to find the perfect match for your home.

Contact us to get an instant quote, or call [telme].

What makes our Sydenham sash window company different?

At London Box Sash, we are passionate about preserving the timeless beauty of sash windows while enhancing your home with modern products. Our skilled team focuses on using the highest quality materials and providing flawless sliding sash window installations that respect the traditional aesthetics of your property. This dedication to craftsmanship and attention to detail has made our services highly sought after and widely recommended.

John Ellis founded our first workshop in 1980, and since then, we have proudly specialised in crafting double-glazed sash windows and doors designed for lasting durability.

With a commitment to traditional craftsmanship and modern innovation, we have grown steadily over the decades. By continually investing in state-of-the-art machinery and refining our techniques, we ensure that every product we create meets the highest quality standards, blending timeless aesthetics with superior performance for homes across the region.

We take the time to explain the intricacies of sash windows, from their history to their functional benefits, ensuring you are fully informed at every step. Whether you are restoring an older property or adding character to a new build, our team is committed to helping your home find its perfect style.

Another client said:

I was very happy with the bespoke casement window they installed in my property. The company also agreed to repair it promptly after a number of years. London box sash install high quality timber windows and seem to care about their customers.

For images of our recent sash window installation projects, please check out our portfolio.

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    We fit Accoya sash windows and wooden sash windows in Forest Hill, SE23

    Forest Hill in South-East London is known for its charming, tree-lined streets and beautifully preserved period properties, many of which feature classic sash windows integral to their architectural character.

    From Georgian townhouses to Victorian terraces, these homes reflect a timeless elegance that makes Forest Hill a sought-after area for homeowners. However, due to the age of many of these properties, original sash windows may have become worn or inefficient over time, leading to drafts, condensation, or difficulty in operation. R

    Replacing sash windows with high-quality, energy-efficient replicas can enhance the comfort and aesthetic appeal of these heritage homes. Accoya wood undergoes an innovative acetylation process, making it exceptionally durable and resistant to decay, rot, and insects. This increased lifespan is complemented by its remarkable dimensional stability, ensuring smooth operation and a longer life.

    Accoya’s low maintenance is a key benefit, as its reduced water absorption extends the life of finishes. Its thermal insulation properties improve energy efficiency, making it an eco-friendly option that can lower energy costs. Accoya wood also supports sustainability, offering both the environmental advantages of softwoods and the durability of hardwoods, earning C2C Gold certification.

    Forest Hill A+ rated sliding sash window installation

    Double-glazed sash windows can significantly enhance your home’s energy efficiency. According to the Energy Saving Trust, installing A-rated double-glazed windows in a single-glazed semi-detached home can save homeowners around £195 per year.

    The insulated air space between the glass panes in double or triple glazing helps reduce heat transfer by slowing down convection and conduction, keeping your home warmer for longer and lowering heating costs, making it a smart investment for energy-conscious homeowners.

    Please see our blog: How long do double glazed windows last?

    Rebecca Wood
    3 weeks ago
    We asked Simon to come and quote for replacing 6 tired windows – 3 casement and 3 sash windows. Simon arrived on time and was very polite. What impressed me most was his honesty and integrity. He asked how long we intended to stay in our home and he did a thorough review of the condition of our windows and then said, we would be better off just repairing them. In this day and age it's rare to find someone not trying to force sell things to you. Chapeau. Rest assured we will use this company in the future when we do need to replace our existing windows.
    Richard Bailey
    1 month ago
    This was the 3rd time using London Box Sash Windows to replace 1890s Victorian sash windows, having been very impressed with them previously. Both high quality windows and doors (manufactured locally!), and friendly and efficient staff. This time it was to replace a very worn out rear ground floor side return bay window. Jake was the first point of contact for assessing and quoting – on time and courteous.Then surveyor Harry who dealt straightforwardly with issues like precise measurements and the practicalities around the installation date. This was confirmed promptly on a standby basis (with the incentive of a small discount). It was reassuring to opt again for privacy glazing for this window (various designs available) and acoustic glazing. The installer Audrius arrived on time and carefully protected all areas in the room. The replacement took a day with additional filling and painting the following morning (including around the exterior bonnet roof). Along with skilled workmanship, the area was cleaned up afterwards. The window surrounds could then be easily painted by me after a couple of days. My interactions with Judith and Sam in the office were always very responsive – organising appointments, invoicing (exactly as agreed) and dealing with any snagging issues. Should a 4th requirement to use them arise, I'd be very happy to choose this company again.
    Jane Watkins
    1 month ago
    Great service, great quality product and polite professional staff. Very pleased with final result. Seamless from start to finish. Would highly recommend anyone looking to replace their sash windows to use this company.
    Aalia Khan
    2 months ago
    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
    3 months ago
    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
    3 months ago
    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
    3 months ago
    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
    3 months ago
    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.

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

    • Beckenham
    • Catford
    • Dulwich
    • Forest Hill
    • Honor Oak Park
    • Lewisham
    • Norwood
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    Would you like a quote for sash windows or casement window installation Forest Hill? Call London Box Sash now

    For an estimate for casement windows or replacement sash windows near you, please call [telme] or email [emailme].

    Call our team for sash windows Putney.