Change the performance, not the character
Replacement Sashes
Keep the character. Replace what no longer performs.
We make replacement sashes around the house in front of us. We match the proportions, meeting rails, glazing bars, horns and mouldings that give the property its character, then improve draught control, glazing, security and everyday comfort.
A replacement should belong
We make the new window look as though it has always been there.
The meeting rails, horn shape, glazing pattern, internal mouldings and relationship to the masonry all matter. We do not start with a generic modern profile and force it into the opening.
We start with the original architecture, then layer modern performance into it. That means you can improve warmth, draught control, security and glazing without flattening the character of a Georgian, Victorian or Edwardian elevation.
Matched sash and frame proportions
Solid-hardwood construction
Modern draught seals and secure hardware
Glazing chosen room by room
Explore finishes & detailing →
Our replacement sashes
London façades, interiors and the details that make the difference.
What we match
The small proportions are what make the replacement convincing.
Meeting rails
We position and size the meeting rails around the original window so the elevation keeps its established rhythm.
Horns & glazing bars
We develop horn shapes and glazing-bar profiles around the period and surviving details of the property.
Internal mouldings
Where original mouldings remain, we can develop the new internal joinery around them rather than introducing a generic trim.
Paint & hardware
We can discuss exterior paint matching by reference and coordinate antique brass, chrome, satin chrome, black or pewter hardware.
Better performance, same visual language
We improve the window without making the house look newly windowed.
The point of replacement is not to advertise the replacement. We want the improvement to show up in warmth, quietness, security and smooth operation while the architecture still feels settled and familiar.
Repair or replace?
We do not replace original joinery just for the sake of replacing it.
Where significant original fabric survives, restoration may be the better answer. Where the joinery is beyond sensible repair, badly altered or unable to deliver the performance the room needs, replacement can be the right route.
We can help you decide which openings genuinely need replacement and which are better treated through restoration.
Explore window restoration →Our process
Measure the existing character before we redraw the window.
Survey
We record the opening, existing joinery, sightlines, mouldings and the wider façade.
Design
We agree the proportions, horns, bars, glass, paint and hardware around the property.
Craft
We manufacture the new sash windows in solid hardwood using traditional joinery knowledge.
Install
We fit and finish the new windows so they sit naturally within the existing building.
Questions before a survey
Replacement Sashes FAQs
We can give a more precise answer after seeing the existing windows and understanding the property.
Can you make the replacements look like the originals?
Yes. We can develop mouldings, glazing bars, horns, meeting rails and overall proportions around the existing windows and the architecture of the property.
Will replacement sashes reduce draughts?
Yes. Modern perimeter seals, careful fitting and appropriate glazing can improve draught control while keeping traditional-looking proportions.
Can the inside and outside be different colours?
Yes. We can discuss different interior and exterior paint colours where the project calls for them.
Should I restore rather than replace?
Sometimes. If important original joinery survives and can be sensibly repaired, restoration may be the better route. We can assess that during the survey.
Start your project
Show us the windows you want to improve.
We’ll look at the property, the existing joinery and the performance you want from the new windows before we recommend a replacement specification.
01753 858196 info@boxsash.com
Get in touch
Tell us a little about your project and one of our friendly team will be in touch.
