uPVC (unplasticized PVC)
uPVC stands for unplasticized polyvinyl chloride. It is PVC made without the plasticizers that make it flexible, so it stays rigid enough to be extruded into window and door frames. It is the most common window frame material in Europe.
PVC is used for many things, from garden hoses to drain pipe. The "u" means no plasticizer has been added. Plasticizer is what makes PVC soft and bendy. Without it, the material stays stiff and holds its shape, so it can be extruded into the long, hollow profiles that window frames are made from.
The material is only half of it. Performance comes from the shape of the profile. A European uPVC frame is extruded with several internal air chambers instead of one hollow cavity. Larger sashes get a galvanized steel insert in the biggest chamber so they do not sag. The corners are welded, not screwed, and the sash closes against compression gaskets.
A typical European uPVC window, in numbers
These figures are for the flagship uPVC tilt and turn system I carry, as listed in my estimator:
| Spec | Value |
|---|---|
| Frame depth | 3.35 in. (85 mm) |
| Internal chambers | 6 |
| U-factor, double glazed | 0.22 |
| U-factor, triple glazed | 0.13 |
| Estimator rate, windows | about $26 per sq ft, +/-10% |
| Estimator rate, doors | about $42 per sq ft, +/-10% |
For comparison, the everyday aluminum system in the same estimator is $56-62 per sq ft. uPVC is the best price for the performance I can ship. Aluminum is the choice when the design needs slim sightlines, very large units or dark colors on a hot elevation.
Where uPVC fits
uPVC works for most residential window schedules: tilt and turn, fixed lights, entry doors and mid-size sliders. It does not do the thinnest frames. It also has span limits that aluminum does not have, so a 12-foot lift-and-slide or a steel-look grid is an aluminum job.
A per-window price list for eight common sizes is in uPVC tilt and turn windows - price list. For a full schedule, run it through the estimator. Triple glazing adds about 15% on uPVC, and a nailing fin adds 8%.
Common questions
- Is uPVC the same as vinyl?
- It is the same base material - US vinyl windows are also made of rigid PVC. The difference is in how the profile is built. A European uPVC frame is usually deeper, has more internal chambers, uses steel reinforcement in larger sashes, and carries tilt and turn hardware with multi-point locking.
- Why does a uPVC window show a gap when closed?
- A thin, even shadow line between sash and frame is normal - that is where the gaskets sit. If the gap is uneven, or light or a draft gets through, the sash needs adjusting. European tilt and turn hinges can be adjusted with a hex key, so this is a service fix, not a replacement.
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