Transforming traditional sashes

Innovative hidden boxed-spring sash window joins Mumford & Wood's Conservation Secure collection

In association with

Vertical sliding sash windows are traditionally operated by weights and pulleys with the modern alternative featuring a cost-effective spring balance mechanism. The Conservation Secure collection of period-style timber windows and doors by Mumford & Wood, however, now includes an option in which the pre-tensioned spring balance is hidden from view to maintain authentic styling. 

In conservation areas, and in more modern buildings where the structure cannot accommodate the rebate of the traditional box sash, but where the spring balance option is not considered visually authentic, Mumford & Wood has designed this simple box cover to completely conceal the spring balance. This allows the vertical sliding sash window to be more in keeping with a traditional appearance. In addition, the product is fully security tested to PAS24:2012 to achieve Secured by Design accreditation, while the unique design allows quick, easy and efficient maintenance. The traditional weights and pulleys option is also still available in the Mumford & Wood product portfolio which is suitable for listed properties and those in conservation areas.

'This simple but innovative introduction to the Conservation Secure collection means that the springs are hidden by virtue of being completely concealed within the box frame,' says Owen Dare, technical director, Mumford & Wood. 'Aesthetically it will satisfy architects, developers and home owners who do not want to detract from the authentic styling of our period windows. As most of our products are now SBD accredited this window is available with full security testing to PAS24:2012 and sits perfectly in the high performance Conservation Secure collection.'

The new product design allows for the spring balances and simple box cover to be easily removed and, together with the Mumford & Wood click-fit staff and parting bead, decorating the sash frame is quick, easy and efficient.

BRE A+ rated Conservation products are manufactured to the exacting standards of the British Woodworking Federation’s Wood Window Alliance scheme at the company’s state-of-the-art facilities in Tiptree, Essex. High performance, thermally efficient and acoustically sound, only clear-grade, FSC certificated timber which is engineered for ultimate strength, stability and robustness is used in the manufacturing process. Mumford & Wood’s products have a life expectancy of 55-65 years or more and a variety of micro-porous finishes – paint, stain or dual colour – will ensure they look and perform better for longer. Many carry Secured by Design accreditation and all products carry the BSI Kitemark and are Energy Saving Trust listed.

For more information and technical support visit:



01621 818155