Our timber box sash windows are carefully designed to replicate the traditional proportions of historic frames, meeting rails, and glazing bars, while delivering outstanding modern performance. Crafted from engineered timber using advanced manufacturing methods, they retain the timeless appearance of original English box sash windows but with significant improvements in security, thermal efficiency, and durability.
Developed through close collaboration between our technicians and an expert architect, our vertical sliding sash windows faithfully capture the simple elegance seen from Christopher Wren’s early designs through the Georgian, Victorian, and Edwardian eras. This window style is available in two box depths: standard and slim. Samples of both the standard and slim sash windows are available to view in our Horndean and Winchester showrooms.
Our Sash Box is available in two depths: slim and standard. Samples of both our standard and slim sashes are available to view in our Horndean & Winchester showrooms.
Standard Sash - 176mm
The Standard Sash, with a depth of 176mm, is a recreation of traditional box sash proportions. It offers a robust, classic look ideal for period properties or homes where deeper reveals are in place. With ample space to accommodate high-performance double glazing, the Standard Sash provides outstanding thermal insulation, strength and long-term durability.
Slim Sash - 142mm
The Slim Sash, at 142mm is the slimmest traditional sash window available in the UK allowing the window to finish flush with the original plaster lines without projecting into the room in most instances. The Slim Sash carries narrower double glazed units maintaining the same level of insulation by using high performance krypton gas between the glasses.
Weights and Chains
Our most popular sash window is hung on smooth running chains which is available in brass, chrome or stainless steel. Our chains not only provide a very pleasing gliding action in use but also make for an interesting design feature, offering both visual appeal and mechanical reliability.
Weights and Chords
For the purist we also offer the option of hanging our sash on traditional sash cords, which are pre-stretched to accommodate the weight of modern double glazed units. This option maintains an entirely authentic appearance, perfectly suited for conservation areas and sensitive restoration projects where original detailing is crucial.
Spring System
Sash windows may also be hung on spring balances. This is particularly useful in more modern buildings which do not have sufficient rebate to accommodate a full sash box.
“Box sash windows are a hallmark of British architectural heritage, combining timeless elegance with practical design. Our modern timber box sash windows honour traditional craftsmanship while embracing the latest advancements in security, insulation and durability. They offer homeowners the best of both worlds: authentic period style with the comfort and performance expected from today’s finest window systems."
Our process starts with a personalised consultation where a door specialist listens to your needs and recommends styles, colours, glazing and hardware to suit your home's character. Once you’ve made your selections, we take precise measurements to ensure a perfect fit and arrange an installation date that works for you. Our experienced team carries out the installation with care and precision, ensuring every door and window is properly fitted, and we'll guide you through how to operate and maintain your new products once the work is complete.
Aside from their timeless and elegant appearance, timber box sash windows are a favourite choice for both period property restorations and modern homes seeking traditional character with contemporary performance.
With their classic vertical sliding operation and authentic proportions, box sash windows suit a wide range of properties, from Georgian townhouses to Victorian villas and beyond. Their ability to combine historical charm with modern efficiency makes them a versatile and attractive choice.
Modern box sash windows incorporate robust locking mechanisms and high-quality fittings to deliver excellent security without compromising their traditional appearance. The solid construction and attention to detail provide added peace of mind for homeowners.
Timber box sash windows combine the natural insulating properties of wood with advanced glazing options to reduce heat loss and eliminate draughts. Multi-layered seals and high-performance glazing help maintain a comfortable home all year round, while also supporting lower energy bills.
Constructed from engineered timber and finished with durable coatings, our box sash windows are designed to withstand the elements and resist common issues like warping and swelling, ensuring smooth operation and long-lasting beauty with minimal maintenance.
"Could not fault Timber Windows of Horndean, everything was quoted and all on time. The work was done professionally and cleanly."
"We were looking for hardwood and excellent quality which we found here. We loved that it was a family business - the sales personnel and the fitters answered all my questions immediately or found out and gave feedback as soon as they could - amazing!"
"The reason for choosing Timber Windows of Horndean & Winchester was because I was recommended by a friend, who has used the company before and was very pleased with their work. The whole process moved very smoothly, with all the appointments kept on time. All the staff are friendly and courteous. The installation teams were excellent and the clean up at the end was impressive. I would recommend Timber Windows of Horndean & Winchester. "
