Sash windows · London
Timber sash windows for London's period homes.
Box sash, made to match your originals — genuine linseed oil putty and true through glazing bars.
How we build them
Box sash, made to match your originals
We take the profiles off your existing sashes — the horns, the meeting rail, the width of the glazing bars — and build new box sash windows to the same section. Nothing comes off a shelf.
Each sash runs on cords, weights and pulleys, the way box sash windows have always worked. Spiral balances are quicker to fit, but they change how the window sits in the frame and how it moves. On a period property, that difference shows.
Draught-proofing goes into the frame, not across the face of it — brush seals set into the rebate, out of sight once the window is closed.
- Cords, weights & pulleys
- Matched horns
- Draught-proofed
The detail that shows
Genuine linseed oil putty
How we do it
Glass is bedded in linseed oil putty, knifed to a clean bevel and left to skin before painting. It moves with the timber as it expands and contracts, and can be raked out and renewed decades later without disturbing the sash.
The usual shortcut
A timber bead pinned over the glass, or silicone shaped to imitate putty. Both are quicker to fit. Both sit proud of the frame, and the line they leave reads as modern from the pavement.
It is the first detail a conservation officer looks for — and the first one a neighbour notices.
Warmth without the bulk
Slim-line double glazing
12–16mm
What we fit
24–28mm
Standard unit
A slim-line unit sits inside a period glazing bar without forcing it wider. You get the thermal improvement, and the window keeps the proportions it was built with. A standard unit performs well, but the bar has to grow to hold it — and once the bar is that thick, the window stops reading as a period window.
Where a listed building calls for it, we also make single-glazed sashes. The final decision rests with your conservation officer.
How it works
From first survey to final coat
Survey
We measure every opening, take the profiles off your existing sashes, and check what applies to your property.
Drawings & quote
You see the sections drawn before anything is cut, with a written quote and no obligation.
Made
Built to your measurements in our workshop, putty-glazed and painted before it leaves us.
Fitted
Installed by our own team, never subcontracted. FENSA certificate on completion.
Sash window questions
Before you decide
Can you repair my sashes instead of replacing them?
Often, yes — and where the timber is sound, repair is usually the better option. Rot is frequently limited to the bottom rail or a cill, and those parts can be cut out and replaced without touching the rest of the sash. We'll tell you honestly what yours need.
Can I keep my original box frames?
Where the frames are sound, we can make new sashes to run in them — new cords, weights rebalanced, brush seals added. It keeps more of the original building, and it usually costs less than replacing the whole window.
Will they still rattle and stick?
No. Brush seals set into the frame close the gap that causes the rattle, without stopping the sash from running. Sashes stick when they've been painted shut or the cords have gone — both are things we sort out as part of the work.
Can you match the horns and glazing bar profiles?
That's the starting point. We take the profiles off your existing sashes — horn shape, meeting rail, bar width — and cut the new timber to the same section, rather than fitting a stock profile.
Are your sash windows suitable for listed buildings?
We make single-glazed sashes where a listed building calls for them, and slim-line double glazing where it's accepted. What's appropriate varies between boroughs, and the decision rests with your conservation officer.