Window Style · Heritage Look, Modern Performance
Sliding Sash Windows
Traditional vertical sliding sash windows for Georgian, Victorian and Edwardian properties — with A‑rated thermal performance and a Constant Force Spiral Balance system that won’t drop the sash.
The sliding sash window is the defining feature of Irish Georgian, Victorian and Edwardian architecture — vertically sliding sashes, fine astragal bars, slender meeting rails. Done badly in plastic, it looks wrong. Done properly, it’s the single most authentic period detail you can keep.
Wright Windows manufactures sliding sash at our Milltownpass factory in uPVC, hardwood timber, aluclad and our flagship R9 Legacy composite system. Every variant uses a Constant Force Spiral Balance — the sash holds at any height without rope cords, weights or sticking. For planning‑controlled properties and conservation areas, our R9 Legacy flush‑sash is the spec that gets approved.
- Heritage Proportions
- Spiral Balance System
- A-Rated Thermal Spec
- Made in Westmeath
How They Work
Vertical sliding — no cords, no weights, no drop.
Two sashes — upper and lower — slide vertically past each other in the frame. Open the lower sash up, open the upper sash down, or both for stacked ventilation. The sashes tilt inwards on a pivot for cleaning the outside from inside.
Traditional timber sashes ran on rope cords with cast‑iron counterweights hidden in the frame — the cords broke, the sash dropped. Our modern Constant Force Spiral Balance system replaces all of that with a hidden steel spring at each side. The sash holds at any height, slides smoothly, and the mechanism is sealed for life.
Why Sliding Sash
Key Benefits
- Authentic period look. Slim meeting rails, run‑through astragal bars and putty‑line detail that reads as timber.
- A‑rated thermal performance. Triple‑glazed sash systems reach U‑values down to 0.8 W/m²K (R9 Legacy) — PassivHaus territory.
- Constant Force Spiral Balance. Sealed steel spring system — sash holds at any height, no cord to break.
- Tilt‑in cleaning. Both sashes pivot inwards for safe cleaning of the outer glass.
- Approved for conservation areas. R9 Legacy has been accepted on planning‑controlled work where standard uPVC sash would be refused.
Available Materials
Sliding Sash, in Four Specifications
From budget uPVC to flagship R9 Legacy composite — the right choice depends on your property and whether planning approval is in play.
Specifications
Configurations & Detail
Sash Layouts
1‑over‑1, 2‑over‑2, 4‑over‑4, 6‑over‑6 Georgian. Run‑through astragal bars, internal bars or true‑divided lights.
Balance System
Constant Force Spiral Balance — sealed steel spring at each side. Holds at any height, slides smoothly, no cord maintenance.
U-Values
From 0.7 W/m²K (uPVC triple), 0.8 W/m²K (R9 Legacy triple) and 0.84 W/m²K (timber/aluclad triple).
Best Suited For
Where sliding sash belongs.
- Georgian, Victorian and Edwardian properties where vertical sliding sash is the original style.
- Protected structures and planning‑controlled refurbishments — spec R9 Legacy.
- Period‑style new builds matching neighbouring streetscape proportions.
- Replacement of rotten or dropping timber sashes where the look must be retained.
- Upper‑floor windows on side passages where outward‑opening is blocked.
Customisation
Colours, Bars & Detail
Heritage colour palette across timber, aluclad and R9 systems. Authentic astragal bar detail, run‑through or true‑divided.
- R9 finishes: Clotted Cream, Cotswold Green, Eclectic Grey, English Oak, Irish Oak, plus dual‑colour.
- Timber finishes: Factory paint or translucent stain in any RAL or RAL‑adjacent colour.
- Bars: Astragal (genuine putty‑line bar), internal bars between glass, or true‑divided lights.
- Furniture: Brass, chrome or black sash lifts and meeting rail latches.
Recent Work
Sliding Sash Project Gallery
Sliding Sash FAQ
Common Questions
Can I get sliding sash windows that meet conservation planning rules?
Yes — for planning‑controlled or protected‑structure properties, our R9 Legacy flush‑sash composite system has been accepted where standard uPVC sash would be refused. The 100mm frame depth, chamfered putty‑line detail and mechanically butt‑jointed corners replicate 19th‑century timber proportions. For full timber requirements, our hardwood sash system is the spec.
Will the sash drop or stick like an old timber one?
No. Traditional timber sashes used rope cords and counterweights that broke or jammed. Every Wright sliding sash uses a Constant Force Spiral Balance system — a sealed steel spring at each side that holds the sash at any height with no maintenance and no failure mode.
Are sliding sash windows energy efficient?
Modern sliding sash is, yes — we achieve U‑values from 0.7 W/m²K (uPVC triple) up to 0.84 W/m²K (timber/aluclad triple), all comfortably A‑rated. The historic perception of draughty sash windows came from worn‑out cord‑and‑weight systems and single glazing — not present on a modern sash.
Can I clean the outside of the glass from inside?
Yes — both sashes tilt inwards on a pivot, giving safe access to the outer face of both panes from inside the room. Useful on upper floors and town‑centre properties without external access.
Ready to spec your sliding sash windows?
Visit our Milltownpass showroom to see R9 Legacy, timber and aluclad sash systems side by side, or request a free no‑obligation written quote.
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