uPVC is unplasticised PVC, a rigid, strong version of PVC used for window frames and external doors. Standard PVC contains plasticisers that make it soft and flexible, so it’s used for things like cable insulation and flexible tubing, not windows. When companies advertise “PVC windows”, they almost always mean uPVC windows.
What Is PVC?
PVC (polyvinyl chloride) is a widely used plastic. Plasticisers are added to make it soft and bendable, which suits products like electrical cable insulation, flexible tubing and shower curtains.
Because it’s flexible, standard PVC isn’t strong or stable enough for window frames or external doors.
What Is uPVC?
uPVC stands for unplasticised polyvinyl chloride. It contains no plasticisers, which makes it rigid, strong and stable. It’s also sometimes called PVCu or PVC-U, which are the same material.
These properties make uPVC ideal for windows and doors:
- Weather-resistant: it won’t rot, rust or warp
- Energy efficient: uPVC frames insulate well
- Low maintenance: no painting or sealing needed
- Doesn’t fade quickly in sunlight
- Recyclable
What Is uPVC Used For?
Because it’s rigid and weather-resistant, uPVC is mainly used in building:
- Windows: the most common use in UK homes
- Doors: front, back, French and patio doors
- Pipes: drainage and soil pipes
- Cladding, fascias and soffits: weatherproof exterior trim
- Guttering: rainwater systems
uPVC vs PVC: Key Differences
| uPVC | PVC | |
|---|---|---|
| Plasticisers | None | Yes |
| Structure | Rigid and strong | Soft and flexible |
| Weather resistance | Excellent | Lower |
| Used for | Windows, doors, pipes, cladding | Cables, tubing, flexible products |
| Suitable for windows and doors | Yes | No |
Are “PVC Windows” the Same as uPVC Windows?
Yes, in practice. Many companies say “PVC windows” or “PVCu windows” in adverts, but they mean uPVC. Flexible PVC isn’t used for window frames.
Why uPVC Is Used for Windows and Doors
Windows and doors need to stay rigid, seal tightly and cope with rain, wind and temperature changes for decades. uPVC does all of this, which is why it’s the most popular frame material in the UK.
- Windows: see our range of uPVC windows, including casement, tilt & turn, sash and bay windows.
- Doors: our uPVC doors have fully reinforced frames and multi-point locking. We also supply French doors and patio doors.
Comparing uPVC with aluminium or timber? See our window frame materials guide. Want to know how uPVC frames help keep heat in? Read our guide to the most energy efficient windows.
Is uPVC Environmentally Friendly?
uPVC windows last for decades and can be recycled at the end of their life. Old frames are collected and recycled into new products through Recovinyl, the PVC industry’s recycling scheme, which operates across Europe. According to the British Plastics Federation, the UK has consistently led Europe in the volume of PVC-U collected and recycled, and window profiles are the largest contributor to UK PVC-U recycling.
FAQs
What is uPVC?
uPVC is unplasticised polyvinyl chloride, a rigid, strong plastic used mainly for windows, doors, pipes and cladding.
Is uPVC the same as PVC?
No. uPVC is unplasticised PVC. It’s rigid and strong, while standard PVC is flexible.
Is uPVC the same as PVCu?
Yes. uPVC, PVCu and PVC-U are all names for the same material.
Why isn’t PVC used for windows?
Standard PVC contains plasticisers that make it flexible, so it isn’t rigid or weather-resistant enough for window frames.
Can uPVC windows be recycled?
Yes. Old uPVC frames can be collected and recycled into new products, including new window profiles.
Is uPVC fire safe?
uPVC doesn’t ignite easily and tends to stop burning once the flame source is removed. Like all plastics, though, it gives off harmful smoke and fumes if it does burn.
How long do uPVC windows last?
Typically 20–40 years with basic care.
Does uPVC need maintenance?
Very little. Wipe it down regularly and check the seals once a year. See our guide to cleaning uPVC window frames.
Get a Free Quote
Trade uPVC Windows is a family-run company that has supplied and installed A-rated uPVC windows and doors across Glasgow and the Central Belt since 2013. We’ll measure for free and give you a no-obligation quote.
