What Is a Sliding Sash Window?
A sliding sash window has two glazed sections, or sashes, which move vertically within the frame rather than opening outwards like a conventional casement window.
The style is strongly associated with Georgian, Victorian and Edwardian homes and remains one of the most distinctive window designs for traditional British properties.
Amber’s modern sliding sash windows reproduce the appearance and proportions of traditional timber sash windows using low-maintenance uPVC frames, modern double glazing and contemporary security and weather protection.
They are sometimes also described as vertical sliding windows or vertical sliders.
Traditional Appearance Without Traditional Timber Upkeep
Original timber sash windows are an important part of the character of many older properties, but ageing frames can require regular painting, repair and maintenance.
Modern uPVC sliding sash windows are designed to retain much of the traditional appearance while providing the benefits expected from a contemporary replacement window.
Traditional Proportions
Designed to recreate the distinctive vertical proportions and appearance associated with traditional sash windows.
Timber-Look Finishes
Woodgrain finishes and traditional detailing can create a much more authentic appearance than a standard smooth white uPVC frame.
Modern Glazing
Modern sealed glazing units provide substantially improved thermal performance compared with many ageing single-glazed originals.
Low Maintenance
uPVC frames do not require the regular sanding and repainting associated with traditional painted timber.
Easy Cleaning
The Amber sliding sash system includes tilt functionality, allowing the sashes to tilt inward so the external glass can be cleaned from inside the property.
The Details That Make a Sash Window Look Right
With a period-style window, the small design details matter.
A modern sash window can look very different depending on the proportions, glazing bars, sash horns, frame finish and hardware selected.
Balanced Traditional Proportions
The standard window uses an equal 50/50 split between the top and bottom sashes, producing balanced sightlines and traditional proportions.
Alternative sash split ratios are also available where the design of the property requires them.
Traditional Sash Horns
Decorative or run-through sash horns are available to reproduce one of the distinctive details associated with original timber sash windows.
Deep Bottom Rail
An optional deep bottom rail can be specified to reproduce the heavier lower-sash proportions typically seen on traditional timber sash windows.
Georgian & Astragal Detailing
Georgian and astragal-style glazing bars can be added to reproduce the divided-light appearance of traditional sash windows, from a simple centre bar to full Georgian layouts.
Traditional Glazing Bar Designs
The glazing pattern has a major influence on how authentic a sash window looks.
Amber’s sliding sash windows can be specified with a variety of glazing-bar layouts to complement different ages and styles of property.
Layouts shown are examples. On swept heads and arched frames the top sash is always fixed. Options are available subject to window size and specification.
A Complete Period-Property Window Transformation
At this Victorian property in Poringland, NR14, Amber supplied and installed 19 timber-look sliding sash windows, together with four flush casement windows, one back door and one aluminium triple-track sliding door.
The sash windows were specified to retain the traditional character of the property while introducing modern glazing, security and lower-maintenance PVC-U frames.
Traditional detailing included white woodgrain finishes, deep bottom rails and sash horns.
Sliding Sash or Flush Casement — What’s the Difference?
Both can give a traditional property a much more sympathetic appearance than a standard modern casement window, but they operate very differently.
Sliding Sash
Best suited where the traditional vertical-opening appearance is important.
- Two sashes move vertically
- Strongly associated with Georgian, Victorian and Edwardian architecture
- Particularly appropriate where the original property had sash windows
- Available with traditional detailing such as sash horns and Georgian bars
Flush Casement
Best suited where a traditional outward-opening casement appearance is preferred.
- Hinged sash opens outward
- Opening sash sits flush with the outer frame
- Suitable for cottages and many period or character homes
- Can recreate the appearance of traditional flush timber casements
The better choice usually depends on the original architecture of the property, how you want the window to open and the level of traditional detailing required.
If you’re unsure, Amber can show you both styles at our Norwich showroom. You can also see our Replacement Windows Norwich page.
Energy-Efficient Sliding Sash Windows
Amber’s sliding sash windows use multi-chambered PVC-U frames and sashes together with modern sealed glazing to provide strong thermal performance while retaining traditional styling.
As standard, the windows achieve an A Window Energy Rating with a U-value as low as 1.4 W/m²K. The full specification is summarised alongside.
Weather Protection
The sash system incorporates weather seals designed to limit air and water ingress while allowing the two sashes to move correctly within the frame.
Acoustic & Laminated Glazing
Laminated and acoustic glazing options are available where additional sound reduction or security performance is required.
Standard Amber sash specification
- A Window Energy Rating
- U-value as low as 1.4 W/m²K
- 24mm argon-filled double-glazed unit
- Multi-chambered PVC-U frames and sashes
- BSI Kitemarked system
- Fully sculptured profiles
- Equal sightlines
Modern Security & Safety
Although designed to reproduce a traditional window style, Amber’s sliding sash windows use modern locking and safety hardware within the PVC-U frame.
Available security and safety features include:
- Secure sash locking hardware
- Optional anti-jemmy security bar
- Optional sash child/travel restrictors
- Tilt restrictors for controlled inward opening
Easy-Clean Tilt Facility
Both sliding sashes can tilt inward, allowing the external glass surfaces to be cleaned safely from inside the property.
Tilt restrictors provide additional control and safety.
Choose a Finish to Suit Your Property
Sliding sash windows are available in a broad range of smooth and woodgrain finishes, from traditional white and cream through to heritage greens, greys, wood effects and darker contemporary colours.
Colour samples can be viewed at our Hellesdon showroom. On-screen colours are a guide only.
Woodgrain foils give the frames the texture of painted or stained timber, which helps a PVC-U sash window sit naturally on a period façade.
Standard or Heritage Hardware
The finishing details can make a substantial difference to the overall appearance of a sash window.
Choose from standard or more traditional heritage-style hardware depending on the look you want to achieve.
Sash accessories
Travel restrictors, lift hooks, D-handles and pole eyes (for high-level sashes) are available to suit the window and how it will be used.
Standard or heritage locks and fasteners
Standard hardware gives a clean, contemporary look. Heritage-style hardware has a more traditional profile suited to period properties.
Hardware finishes
Finishes: White, Black, Chrome, Gold, Satin Chrome, Graphite, Bronze, Antique Black.
Available finishes vary by hardware item and specification.
Are Sliding Sash Windows Suitable for Period Properties?
Yes. Sliding sash windows are particularly suited to Georgian, Victorian and Edwardian-style homes because they recreate the vertical proportions and opening style associated with traditional timber sash windows.
This makes them a popular choice for homeowners who want improved insulation and lower maintenance without replacing the original character with a conventional casement design.
They are especially relevant to areas of Norwich with large numbers of Victorian and Edwardian properties, including the Golden Triangle. See our page on replacement windows in Norwich.
Can uPVC Sash Windows Be Used in a Conservation Area?
Sometimes, but it depends on the property and the applicable planning controls.
A high-quality timber-look uPVC sash window can reproduce many traditional details, but this does not mean uPVC will automatically be acceptable in every conservation area.
Listed buildings and properties subject to Article 4 Directions or other specific restrictions may have much stricter requirements, including requirements relating to materials, glazing, profiles and detailing.
Amber can help customers compare the available product options, but any required planning or listed-building consent should be established before installation.
How Much Do Sliding Sash Windows Cost?
The cost of replacement sliding sash windows depends on the size and number of windows, frame finish, glazing, Georgian detailing, hardware and the exact specification required for the property.
Because sash windows contain a more specialised vertical sliding mechanism and often include traditional detailing, Amber prices each project to the surveyed specification rather than using a generic online “price per window”.
We will provide a clear quotation once we understand the windows and finish required.
Recent Amber Project Example
Victorian property — Poringland, NR14
- 19 sliding sash windows
- 4 flush casement windows
- 1 back door
- 1 aluminium triple-track sliding door
Contract value: £41,666.40 including VAT
This figure relates to the complete window and door contract listed above. Other works at the property were completed under a separate contract and are not included.
Sliding Sash Windows: FAQs
What is the difference between a sash window and a casement window?
A sash window opens by sliding vertically within the frame. A casement window is hinged and normally opens outwards.
Are your sliding sash windows made from timber?
No. Our PVC-U sliding sash windows recreate the appearance of traditional timber sash windows, with woodgrain finishes and period detailing, while reducing maintenance requirements.
Are sliding sash windows also called vertical sliders?
Yes. Sliding sash windows are also commonly described as vertical sliding windows or vertical sliders because the window sashes move vertically within the frame.
Can I have Georgian bars?
Yes, Georgian-style detailing is available with sash windows, subject to the selected window specification. Different layouts can be used to complement the age and appearance of the property.
Do the windows tilt in for cleaning?
Yes. The current Amber sliding sash system allows the sashes to tilt inward, making the outside glass easier to clean from inside the home.
Are uPVC sliding sash windows suitable for conservation areas?
Sometimes. It depends on the individual property and the relevant planning controls. Traditional-looking uPVC does not automatically mean the window will be acceptable in every conservation area or listed property.
Can sash windows replace old timber sash windows?
Yes, subject to the property and any planning restrictions. Modern uPVC vertical sliders are often selected where homeowners want to retain the traditional opening style and appearance while improving glazing, draught resistance and maintenance.
Can I see window options before ordering?
Yes. You can visit Amber’s Hellesdon showroom in Norwich to compare window styles, frame finishes, glazing and detailing and speak to the team before deciding.
More questions? See our full window FAQs, read about our window guarantee, browse the window gallery or explore all our windows.
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Amber Home Improvements
Unit 52, Hellesdon Park Road
Norwich, Norfolk NR6 5DR
Call: 01603 672638
Opening times
Monday: 8:30am – 5:00pm
Tuesday: 8:30am – 5:00pm
Wednesday: 8:30am – 5:00pm
Thursday: 8:30am – 5:00pm
Friday: 8:30am – 4:00pm
Saturday: 9:00am – 5:00pm
Sunday: 10:00am – 4:00pm
