The Timbawood box sash window is characterised by slender profile sections, fine mouldings and slim glazing bars, in keeping with the original design of period sash windows. We specialise in exact-match, handmade timber windows that preserve the character of listed, conservation and period properties – while upgrading the security and insulation performance.
Depending on the specification and level of preservation required, our timber box sash windows are available in four ranges:
Heritage Range Box Sash Windows
Our Heritage Range box sash windows have been approved for listed buildings throughout London and the South East. More than just a range, our exact-match, bespoke windows are ideal for listed buildings and more stringent conservation areas, with exact-match mouldings, section sizes and glazing bars.
Whether it’s single glazing or slimline double-glazing, hand puttied and hand painted, no requirement is impossible. We offer box frame depths from 120mm that can meet Part L building regulations for thermal efficiency, featuring individually glazed units as slim as 12mm (4-4-4).
Conservation Range Box Sash Windows
Our made to measure Conservation Range box sash windows feature an array of options including our elegant slimline double glazing and slender section sizes, designed for conservation properties and period properties that require exact-match profiles, mouldings and glazing bars.
These box sash windows feature 16mm (4-8-4) krypton filled glazing units with applied glazing bars. Although these windows feature slightly thicker units than the Heritage Range, they are also an elegant solution for architecturally sensitive properties.
Period Range Box Sash Windows
Our Period Range box sash windows are ideal for Edwardian, Georgian and Victorian properties that aren’t listed or in a conservation area. We are able to match the existing design and offer a choice of mouldings including lambs tongue, bevel and ovolo.
These box sash windows feature 20mm (4-12-4) argon filled glazing units with applied glazing bars.
As with the Conservation and Heritage Ranges, the Period Range is made with Accoya timber due to its strength and durability. We offer a full range of glazing options and hardware finishes, as well as a colour-matching service, to ensure the windows are in keeping with the original look of the property.
Traditional Range Box Sash Windows
Our Traditional Range box sash windows, made with engineered redwood, are suitable for period and modern properties, as well as new-build homes.
These box sash windows have a frame depth of 168mm and feature 24mm (4-16-4) argon filled glazing units with applied glazing bars.
As with all our ranges, the Traditional Range box sash window is available with weights and pulleys or spring balances, and a variety of glazing, paint and hardware finishes. All our glazing units feature a Low E soft coat pane for improved insulation, and additional options include acoustic glass for improved sound insulation and laminated security glass. For more information on the specifications available, visit