This article explores all you need to know about uPVC sliding sash windows, including how to buy them and the decisions you need to make. These windows, also called vertical sliding windows, provide the appearance of traditional Victorian-style timber windows with all the benefits of modern double glazing.
Old timber Victorian sliding sash windows are great to look at and complement the property’s style; however, they are often single-glazed and, if not maintained regularly, become rotten and draughty. Modern uPVC sliding sash windows with double-glazing and other state-of-the-art manufacturing techniques provide excellent thermal efficiency and still look authentic, offering the best of both worlds. Sash windows are also available with more modern styling suitable for newly built homes or other projects where the vertically sliding window is best.
What are uPVC sliding sash windows?
It can be confusing because a ‘sash’ is a general term for the part of the window frame that holds the glass panes in place and is the opening element. The traditional Victorian sliding sash windows slide open for ventilation via a pulley and weight system.
uPVC sliding sash windows have two sashes that slide up and down in a frame; a sliding sash does as it says, the opening element slides up and down – often referred to as a Victorian sash, which slides on a rope and weight pulley system, hidden in the frame. Modern uPVC sash windows may look like a rope pulley sliding sash but open outward via a hinge or tilt and turn.
What is the difference between PVCu and uPVC sliding sash windows?
Absolutely nothing! PVCu is used by the door and window industry and is how we in the trade refer to the material. However, uPVC is still used because the public is so familiar with the term. Whether you use PVCu or uPVC, they remain and both are abbreviations for Poly polyvinyl chloride. The ‘U’ stands for Un-plasticised.
What is the best uPVC sash window?
All the brands will claim that their windows are authentic in how they mimic timber sash windows and this is broadly true. The companies will also make claims of having ‘firsts’ in the market. Today there is no absolute best uPVC sash window. However, Masterframe and Roseview are widely regarded as two of the leading brands in the UK today, with Spectus being arguably the most used PVCu system.
Rehau were first to market with a uPVC sash window, but today it’s hard to say that any of these brands offers anything substantially better than the other. There is no best product, so you can comfortably go with the window you like the look of, at the price that is good for you and of course, confidence in your chosen installer.
It’s the quality of the window joints, the foil or colour finishes, the hardware and how the windows look and feel that are the most important factors. However, as long as the window is well made and professionally and correctly fitted, all brands will serve you well.
What are the benefits of uPVC sliding sash windows?
By far, the benefit of sash windows in this material is that you can use them when you want traditionally styled windows. Alumninium sash windows, whilst available are nowhere near as good as plastic for replicating period features.
- Weather Durability: Whilst uPVC sliding sash windows can withstand severe weather, the nature of sliding windows is such that they are never as well sealed as windows that open outwards.
- Robust: uPVC is a strong material and windows come with multiple chambers, steel or aluminium reinforcing.
- Thermally efficient: uPVC naturally has insulation properties in addition to the high specification glass, double or triple glazed.
- Low maintenance: The low maintenance of uPVC windows is already well-known.
- Low price: uPVC is a cheaper material than aluminium or wood.
- Versatility: You can choose any colour and any type of finish, such as smooth or wood effect.
- Recyclable: Yes, uPVC can be recycled up to 10 times.
Technical parts of uPVC sliding sash windows explained
It’s always good to be prepared when chatting with a salesperson, here are some of the technical terms and parts you will come across:
| Sash Window Part | Reason | Explanation |
|---|---|---|
| Sash Lifts – hardware | Operation | Small upside-down U-shaped handles placed, usually in two’s, either end of the bottom opening sash so you can pull up the bottom only sash to open. |
| D Handle – hardware | Operation | A hand width handle you can use instead of Sash Lifts to open the bottom sash. |
| Pole Eyes – hardware | Operation | Used for tall windows these are complete circles, usually in two’s, either end of the top opening sash so you can use a pole to pull down and open. |
| Sash Locks – hardware | Security | Locks with a key that are connected via two parts to both the pull-up and pull-down sash so you can lock them together when closed. |
| Tilt Knobs – hardware | Cleaning | Allow for inward tilting of the sashes for easy cleaning of the external glass. |
| Travel Restrictors | Security | For security reasons they restrict the amount of window you can open and are key lockable. |
| Security Bar | Security | Added as a part of the window cill to increase security when intruders using tools or force try to lever open the bottom sash. |
| Sash Horns | Aesthetics | A decorative feature at the bottom of the top sash frame. |
| Astragal Bars | Aesthetics | Bars fixed to the inside and outside of a pane of glass to separate visually into smaller panes for a Georgian/Victorian style. |
| Staff Bead | Construction | A wood or uPVC strip that holds the sashes in place in a sash window. |
| Mechanical Joint | Construction | A traditional woodworking joint aesthetic that joins two pieces together at a 90-degree angle to hold the corners of a window frame together, also known as mechanical sash joints. |
| Welded Joint | Construction | A welded joint is where the corners are fused together with heat to create a smooth, unbroken bond. A welded mitre joint has a diagonal appearance across the corners of the frame where they join. |
| Midrail | Construction | The vertical frame across the middle of the window (the bottom of the top sash overlapping the top of the bottom sash) |
uPVC sliding sash windows timber-look, design and colour options
You can configure your uPVC sliding sash windows to suit the style and age of your property through your choice of colour, uPVC finish and hardware.
A significant benefit of uPVC sliding sash windows is the perceived endless number of options for finishes and colours, as well as dual colour, one colour on the inside and a different colour on the outside.
The uPVC timber-look or wood grain is achieved by wrapping a ‘foil’ with a fine timber-look imprint around the profiles. Again, uPVC as a material is better for foiled and grained textures and finishes than aluminium.
You can choose the traditional black or brass look window hardware or the more contemporary chrome or satin chrome. Other details you add, such as decorative sash horns and a wood grain foil finish, will keep your windows looking like a Victorian sash.
Most companies will have a small choice of standard, popular finishes and colours to get you started. Other colours and finishes will require an additional cost, so check what your standard options and the optional extras are. Remember, the extras add up when you have about 8-12 windows to replace.
Rehau uPVC sliding sash windows
REHAU Heritage sliding sash windows are carefully crafted to reflect the timeless charm of classic timber frames, while still offering the modern advantages of PVCu.
Developed in collaboration with conservation experts, the Heritage system does look authentic in appearance and designed for British homes. And like most window of this style you get traditional hardware, decorative horns, and optional bottom rails.
ECOslide uPVC sliding sash windows
ECOslide uPVC sliding sash windows are manufactured in Wales by Victorian Sliders. They fabricate the whole window by extruding their own profiles, which are colour-bonded using their in-house facilities. They even make the insulated glass units and their own window hardware and have a uPVC recycling point.
ECOslide uPVC sliding sash windows are manufactured bespoke to your project’s size, colour, glass and hardware requirements. They all come as standard as an A+ rated window, toughened glass, 10 year warranty, security bar and tilt and clean function.
Roseview Windows uPVC sliding sash windows
Roseview Windows manufacture The Rose Collection of uPVC sash windows in Buckinghamshire. The Charisma Rose is their entry-level uPVC sash window, followed by the Heritage Rose.
Their top-of-range Ultimate Rose sash windows offer an excellent alternative to timber, featuring a 35 mm midrail, creating a slim, sleek look. The astragal bars are attached via full-length aluminium carrier bars, not clips and tape, and they have a removable staff bead to allow for tilt functionality for easy cleaning. Finally, it is constructed with end-sealed mechanical joints to give that traditional timber joinery aesthetic; its features make the Ultimate Rose a perfect choice for conservation areas.
Masterframe uPVC sliding sash windows
Masterframes Bygone Collection is their flagship range of sash windows and are only installed by their master installers which they help you to find. The Melody is their entry level sash followed by Harmony available with optional extras.
The Symphony is when the windows must look like timber, due to planning or choice. Available with a U-value of 1.2, wood grain textured acrylic foils and timber style mechanical joints and a slim 39 mm midrail.
Spectus uPVC sliding sash windows
The Vertical Sliding Sash Window combines authentic ovolo detailing with carefully proportioned large and small sash profiles. A 128mm outer frame, deep bottom rail, and elegant sightlines mimic the dimensions of traditional timber sashes, while features like customisable security standards, trickle or glazed-in vents, and a Window Energy Rating of Band ‘A’ deliver modern functionality and efficiency.
A 37mm meeting rail is available with Spectus windows as are hardware and colour options. Spectus are widely regarded as a very authentic-looking PVC-U sash window.
Profile 22 uPVC sliding sash windows
Profile 22 uses the same Spectus profile as is also used by Quickslide, both these brands are part of the Epwin Group.
Victorian Sliders and Roseview Windows only sell to the trade so you must purchase through a window installer or builder where we can help you find one local to you.
Installation and looking after your uPVC sliding sash windows
Correct installation of your uPVC sliding sash windows is key, particularly as there are moving parts than hinged windows. Research your chosen installation company to ensure they have the correct qualifications; ask if they have installed them before and can get them to show you examples.
uPVC sliding sash windows are easier to care for than timber windows, but they still require some TLC. Clean the frames and sashes regularly with mild, soapy water and lubricate the moving parts; ask your installer how to care for and maintain your windows.
More information and where to buy uPVC sliding sash windows.
If you would like some help and advice choosing the right brand and installer for your project, particularly if your property is located in a conservation area, please get in touch with us, and we will be happy to advise.
