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Each double glazed, timber sash window replacement that we manufacture and install across London and Southern England is bespoke.

Established in 1994, Which? Trusted Trader of the Month Nov 2021we have extensive experience working within London and the South of England and can replicate any traditional sliding sash window design. We also offer a supply only service nationwide. Where necessary, our wooden sliding sash windows can be manufactured to adhere to listed building and conservation area requirements.

Bespoke Timber Sash Window Company

Our timber box sash windows are manufactured by our skilled craftsmen in our workshops in Berkshire and come fully factory finished.  We are proud to be Which? Trusted Traders, highlighting the quality of our product and service.

As sash window specialists, with extensive experience working across London and the South, we have designed our Classic range which covers most requirements for Georgian, Edwardian and Victorian homes.

However, if you have specific design in mind, we can manufacture bespoke replacement double glazed sash windows that retain the feel of your period home.

bespoke sliding sash windows London
Accoya bay sash window


The Sash Window Workshop specialise in the replacement of traditional timber sash windows in period properties.  We offer a supply and fit service across London and the South, with a supply only service nationwide.

The majority of our new timber sash windows are made in Accoya, a sustainably sourced modified wood that comes with a 50 year anti-rot guarantee. We can also make windows in alternative hardwood timbers if you prefer.

Our new windows come fully factory painted in white, as standard.  However, if you would like a specific colour we can also colour match to different paint finishes.

If required, customers can opt for special glazing such as stained glass, obscured glass and bowed glass.  We also offer a range of ironmongery options for your new sash windows.

New Wooden Sash Windows Quotation

When you make an enquiry, you will be assigned to one of our experienced sales surveyors who will be able to answer any questions that you have.

If you wish to proceed, you will need to send the signed paperwork to us with the deposit. You will then have a manufacturing survey, when measurements are double checked before manufacturing starts.

During manufacturing we will contact you to arrange an installation or delivery date. If you are having windows supplied and installed, our new wooden sash windows will then be fitted by our expert installers.

Timber window and door manufacturer
Double Hung Sash Windows


Did you know that traditional, double hung sash windows can provide excellent ventilation?

Paul Zisman, Chairman of The Georgian Group, commented on this in The Georgian magazine noting that:

“the traditional sash window has been cited in the media as an ideal means of natural ventilation, allowing cool fresh air to be drawn in below the lower sash and warm, carbon-dioxide rich air, potentially containing virus laden particles or aerosols, to be expelled above the upper sash. Perhaps some of the very sash windows that we continue to enjoy today helped to keep earlier generations of people safe during the various influenza epidemics that affected the country in the eighteenth century. The health benefits of the simple but elegant sash window provide yet another reason to protect it for future generations.”

To view examples of our previous work, view our gallery pages.

Energy Efficient Timber Sash Windows

When looking to replace timber sash windows it is important to ensure that the new sash windows are as energy efficient as possible. At The Sash Window Workshop, our new timber windows are manufactured to provide the modern benefits of double glazing, while preserving the character of your home.

If you are unable to install double glazing, due to planning restrictions, we are also able to manufacture replacement single glazed wooden sash windows or use heritage double glazing, which uses a narrow profile meaning that it is more likely to be approved by planners.

If we are installing replacement sash windows in London and the South of England, we will also draught proof the windows on installation, helping to keep your home warm during the winter months.

Traditional Wooden Box Sash Windows London

Did you know that the traditional box sash window has been around since the 17th century? Amazingly the cord and lead weight design remains almost unchanged with spiral hung sash windows being a more modern development.

Victorian timber sash windows are a key architectural feature in a number of areas around London including Kensington, Islington and Hampstead.  Conservationists are keen to retain the heritage features.  At The Sash Window Workshop we are able to ensure that the patterns and designs are precisely copied to comply with any listed building or conservation area requirements for wooden sash windows in London and Southern England.

In addition to complete new timber sash windows, we can also manufacture and install new sashes into the existing window frames, alongside complete new casement windows and external wooden doors.  If your windows don’t require replacement, we also offer a draught proofing and overhaul service for timber windows.

Our Replacement Timber Sash Window Guarantees


Accoya Anti-Rot




Double Glazing




Draught Proof

*Maximum Guarantees Shown. Please see our Guarantee and Maintenance documents for further information.