Edinburgh does not have a double glazing problem so much as a sash and case problem. The Georgian New Town and the Victorian tenements around it are glazed almost entirely in vertically sliding sashes hung on cords and weights, and the city has around 50 conservation areas, including a UNESCO World Heritage Site. In much of that stock the question is not which frame material to buy but which part has failed. What the work costs sits on our double glazing cost in Edinburgh page, and new units are covered under window replacement in Edinburgh.
Edinburgh calls it a sash and case window
The Scots term is sash and case, and it is worth using when you ring round, because it describes more of the window than the English box sash does. The case is the boxed frame built into the thickness of the wall, hollow down both sides, each hollow holding a cast iron weight on a cord that runs up over a pulley and down to the sash. That hidden box is why original sash frames are so deep, and why a repair is possible at all: the moving parts are reachable, replaceable and individually cheap.
The city's two dominant periods fail differently. Georgian sashes in the New Town carry small panes and slender glazing bars, so there is far more putty line per window to fail. Victorian sashes, in the tenements and later terraces, carry large panes and horns, so the glass is heavier and the cords and weights work harder. Our sash windows guide covers the styles; this page is about what breaks.
What actually goes wrong with a sash and case window
| Part | What it does | How it fails |
|---|---|---|
| Case (box frame) | Boxed frame in the wall, houses the weights | Rot at the foot of the pulley stile, where water sits |
| Sash cord | Carries the sash weight over the pulley | Frays and snaps, so the sash drops or hangs crooked |
| Pulley | Runs at the head of the case | Seizes or wears, so the sash runs stiff and noisy |
| Cast iron weight | Counterbalances the sash | No longer matches the sash after reglazing |
| Parting bead | Separates the upper and lower sash runs | Splits, or is painted solid so the sashes bind |
| Staff bead | Holds the lower sash into the case | Painted over, sprung loose, or worn until the sash rattles |
| Bottom rail and sill | Takes the standing water | First place rot appears, and the commonest timber repair |
| Glazing putty | Beds and seals the glass into the rebate | Cracks and falls out, letting water into the timber |
Component names follow Scots usage. The case is the boxed frame that English guides describe as a box sash.
The cord snaps and the sash will not stay up
This is the fault that makes people ring a joiner, and the least serious on the list. The cord is the only consumable in the system: when it frays through, the counterbalance is gone, so the sash slams shut or hangs at an angle. The staff bead comes off, the sash lifts out, the pocket in the side of the case is opened and a new cord is threaded over the pulley to the weight. The arithmetic matters more than the repair: all four cords are the same age and have had the same weather, so replacing one alone buys the same visit again within a year or two.
Rot in the sill, the bottom rail and the foot of the pulley stile
Water does not attack a sash window evenly. It stands on the sill, sits in the joint between the bottom rail of the lower sash and the glass, and creeps down inside the case to the foot of the pulley stile. Those three places account for most of the rot in Edinburgh sash and case windows, and all three are usually localised, which is what makes the window repairable: the soft section is cut out square and matching timber spliced in, with the case left in the wall. Well-maintained timber has a service life of 30 to 60 years, and a splice restarts that clock on the part that failed.
Failed putty lets water into the rebate
Linseed oil putty beds the pane into the rebate and sheds water off the glass. It hardens, cracks and drops out, and the bare rebate then holds water against timber. Most rot in a sash starts as a putty failure nobody looked at, which is why re-puttying and repainting is not cosmetic work on this window.
Worn beads, rattle and draught
Rattle and draught are one fault seen from two ends: the sash is loose in its channels because the parting bead has worn or split, the staff bead has sprung, and the timber has shrunk away from both. The remedy is draught proofing, which routes discreet brush pile seals into the sash channels and along the meeting rail where the two sashes cross. The window still slides and the cold draught at ankle height goes. It is reversible and invisible from the street, which is why it is the upgrade that gets approved in conservation areas.
The sashes no longer balance
The weights in the case were cast to match the original single glazed sashes. Fit heavier glass and the balance is wrong: the window creeps down on its own, or takes two hands to lift. A competent repair therefore ends with re-balancing, changing the weights to suit what the sashes now weigh. If a quote for reglazing your sashes says nothing about weights, ask before you sign.
What a sash and case repair actually involves
A full refurbishment runs in a set order, and knowing the order is the best defence against a vague quote. The staff bead comes off and the lower sash out; the parting bead comes out and the upper sash follows; the pockets in the case are opened and the weights and cords freed. With the sashes on the bench, rot is spliced, old putty raked out and the glass re-bedded, while the case is repaired in place. Then the beads go back, new cords are hung, the weights are matched, the draught seals are routed in, and the whole thing is repainted. Almost all of the cost is in the taking apart and putting back, which is why four cords in one visit costs far less than four visits.
The Edinburgh sash quotes we check split into two kinds. One prices the window as an object to be replaced. The other prices the parts that failed: four cords, a spliced sill, fresh putty, brush seals, weights re-matched. On a sound case those are not one job at two prices. They are two different jobs.
Double Glazing Cost Calculator Team
Why repair is usually the only route in Edinburgh
Conservation-area density is the strongest driver of regional cost variation in the research we hold, and no city we price has more of it. Where conservation or listed status applies, like-for-like timber sash and case is often the only option the council will accept, and that specification can cost three to five times a standard uPVC casement. Repair is not the sentimental choice there. It is the permitted one, and the cheap one.
Be careful with English guidance here, including our own. Planning and building standards are devolved, so the permitted development and Article 4 framework in our conservation area rules guide describes England, and FENSA, the competent person scheme most double glazing advice assumes, is authorised for England and Wales only. Scotland runs its own system under Scottish building standards, where notifiable work needs a building warrant from the local authority and a completion certificate at the end. So your property's status, and what any given piece of work requires, is a matter for the City of Edinburgh Council, and it is worth establishing before a joiner starts rather than after.
Where the national repair prices stop describing your window
The site's repair cost calculator prices the faults of a modern sealed unit window: a misted or blown unit at £55 to £145, resealing at £50 to £100, a handle at £45 to £150, hinges at £100 to £250. An original Edinburgh sash and case window has none of those parts. No sealed unit to blow, no friction hinge, no espagnolette handle, so most of that table describes a different object.
It applies again where slimline double glazed units have been fitted into the original sashes and one has misted. That is a sealed unit failure and prices like one, since sealed units last 15 to 20 years before the gas escapes. For what new sashes cost instead, use the sash window calculator.
Repair, secondary glazing or replacement
The general framework is set out in our comparison of repair versus replacement and does not need repeating. The sash and case version is short. This is an assembly of separately replaceable parts, so replacing the failed part is nearly always proportionate; the exceptions are a case that has structurally failed, extensive rather than localised rot, and twentieth-century replacements with no heritage value. Timber sash and case replacement in Edinburgh runs £1,500 to £2,500 per window, which is the number a repair quote is judged against.
Where the aim is warmth or quiet rather than function, the third option often beats both. Research by Glasgow University commissioned by English Heritage and Historic Scotland found that secondary glazing can outperform replacement double glazing for thermal efficiency in traditional buildings. It is a second, independent window on the room side, so the sash and case is untouched and the installation reversible, and fitted prices run roughly £300 to £900 per window. The one condition is ventilation: the original outer window must not be sealed airtight, or condensation forms in the gap.
Get quotes from Edinburgh sash window specialists
Sash and case work is joinery and the spread between quotes for the same window is wide, so compare at least three in writing. Tell us what your windows need, and Leads 2 Trade will arrange quotes from installers covering Edinburgh.
Frequently asked questions
Sash and case is the Scots name for the window English guides call a box sash. The case is the boxed frame built into the wall thickness, hollow down both sides, and it houses the cast iron weights that counterbalance the sliding sashes. Edinburgh joiners quote for the whole assembly under that name: case, pulleys, cords, weights, beads and sashes.
A sash cord. It runs over a pulley at the head of the case to a weight inside the box, it is the only consumable in the system, and when it frays through the sash drops shut or hangs crooked. Rot in the sill and the bottom rail of the lower sash is the next commonest, because that is where rain stands, and failed glazing putty is usually the reason the rot started.
Repairing an existing window in place is a different proposition from replacing it, but Edinburgh has around 50 conservation areas including a UNESCO World Heritage Site, and listed buildings are stricter again. Planning and building standards in Scotland are devolved and administered by the local authority, so confirm your property's status and what it requires with the City of Edinburgh Council before work starts rather than after.
Yes. Draught proofing fits discreet brush pile seals into the sash channels and along the meeting rail where the two sashes cross, so the sash still slides normally but the air leakage stops. It is done to the window in place, the case is never removed, and it is reversible, which is why it is the standard route on windows that conservation rules protect.
For a traditional building, research by Glasgow University commissioned by English Heritage and Historic Scotland found secondary glazing can outperform replacement double glazing for thermal efficiency. It leaves the original window untouched and is reversible, it costs roughly £300 to £900 per window fitted, and Historic England puts the sound insulation achievable at up to 45 dBA. Where replacement is not permitted, it is usually the sanctioned upgrade.
Only partly. Those figures price double glazing faults: a misted sealed unit at £55 to £145, resealing at £50 to £100, a handle at £45 to £150, hinges at £100 to £250. An original sash and case window has no sealed unit, no friction hinge and no espagnolette handle, so most of that table describes a different object. It applies again once slimline double glazed units have been fitted into the sashes and one of them mists.