Our bespoke hardwood and Accoya sash boxes are manufactured to replace damaged, rotten or non-original box frames while preserving your property's traditional appearance. Each installation includes handcrafted timber double glazed sashes, integrated draught proofing and FENSA certification for complete peace of mind.
Where original sash windows are beyond practical repair, or have previously been replaced with uPVC, aluminium or casement windows, SashWise can manufacture and install complete new timber sash window boxes with bespoke double glazed sashes.
Each new sash window is designed around the property, with careful attention given to the original proportions, glazing configuration, mouldings and period details. This allows us to reinstate the traditional appearance of a sash window while introducing modern improvements in thermal performance, draught proofing, security and everyday operation.
Our new sash boxes can be manufactured in Sapele hardwood or Accoya, with the most appropriate specification recommended for your property and requirements.
A complete new sash box may be the right option if:
Your original timber sash windows have previously been replaced with uPVC, aluminium or another window style.
You want to reinstate traditional sash windows and restore architectural character to the property.
The existing sash windows, frames or boxes are too extensively damaged to make restoration practical.
You want a complete new timber window incorporating modern glazing, draught proofing and security while retaining a traditional appearance.
Choosing a complete new timber sash box gives you the opportunity to improve performance while restoring the traditional appearance of the property.
Double glazed timber sashes improve thermal performance, help retain heat and can reduce external noise.
New windows can be carefully designed to replicate the proportions and architectural detailing of the originals.
Where traditional sash windows have previously been removed, reinstating them can restore an important character feature of a period property.
The depth of a new sash box can be designed to accommodate a wider range of glazing specifications, including thicker double glazed units and acoustic glazing where appropriate.
All joinery is new, workshop finished and fully draught proofed, giving you a complete window system designed for reliable everyday use.
Completed installations are registered with FENSA where applicable, providing confirmation of compliance with current Building Regulations.
Our team carefully removes the existing sashes and sash boxes, taking care to minimise disruption to the surrounding decoration before preparing the opening for the new window.
The Accoya sash box and double glazed timber sashes are manufactured in our dedicated workshop to the agreed design and specification. Once installed, the sashes operate using the traditional system of weights, sash cords and pulleys, preserving the familiar operation of a traditional box sash window.
An integral draught-proofing system is incorporated into the new window. The sash box is sealed to the exterior brickwork, with new internal architrave and window boards fitted to complete the installation. Where surrounding plasterwork is disturbed during the work, this is made good.
Finally, the chosen window furniture and security locks are fitted and the installation is checked for smooth operation and finish.
Once complete, the installation is registered with FENSA where applicable and a certificate is provided confirming compliance with current Building Regulations.
Please call us on 0208 977 4627 or complete the form below.
We're always happy to discuss your timber window and door needs. Whether you're looking for advice, a detailed quote, or simply want more information about our services, our friendly team is here to help.
Many period properties have lost original architectural features over time, with traditional timber sash windows replaced by uPVC, aluminium or modern casement windows. In other properties, the original sash windows remain but deterioration to the boxes and joinery has progressed beyond the point where restoration is the most appropriate option.
A complete new timber sash window allows these features to be sympathetically reinstated. The style, pane configuration, mouldings and sash details can be tailored to the age and character of the property, or carefully matched to surviving original windows elsewhere in the building.
Our new sash boxes and sliding sashes are manufactured from durable timber, with Sapele hardwood and Accoya available depending on the project. The joinery is prepared and spray finished in the workshop using a micro-porous breathable paint system before installation.
The glazing specification can also be tailored to the property. Depending on the sash-box design and any planning or conservation requirements, options can include high-performance double glazing, slimline heritage units and specialist acoustic glass. See our Timber Window Glazing Options for more information.
Each window is completed with draught-proofing, sash furniture and security locks, with a choice of period and contemporary finishes available to complement existing ironmongery and interior details.
This gives homeowners a complete new timber sash window that retains the visual character of traditional joinery while delivering the comfort, security and performance expected from a modern installation.
