In Belgian renovation, almost every PVC window is custom-made: an older structure is never perfectly square. We measure each opening during the survey, then build a frame fitted to the millimetre — good sealing, a clean fit, no rough patching.
Custom-made is not a marketing argument: it is the fabrication of a unique frame, calculated for your opening. Here is what really counts.
A technician measures each opening on site: width, height, squareness, condition of the structure. The PVC is then cut and welded exactly to those dimensions — no standard frame to wedge in with mortar.
PVC alone flexes on large opening leaves: we insert a galvanised steel profile into the chamber of the frame and the leaf. It is this reinforcement that keeps the alignment and smooth operation over time.
PVC remains ideal up to common dimensions. Beyond that (a very large leaf, an XXL bay), weight and expansion call for aluminium, which is stiffer. We tell you honestly during the survey.
Beyond the rectangle: a gentle arch on a transom, an attic trapezoid, a gable triangle, an oculus. Custom work hugs the unusual openings the standard range never covers.
Bars integrated between the panes (easy to clean) or applied muntins for an authentic look. Essential to respect the character of a listed or characterful facade.
Each window is configured: double or triple glazing, solar control, enhanced acoustic, argon gas, "warm edge" spacer. The glazing accounts for ~70% of the final performance.
* Indicative values for PVC profiles of a common range with steel reinforcement. The exact dimensions, shapes and performance are set during the survey, depending on the condition of your structure.
Custom PVC covers the vast majority of renovations. Here, honestly, is where it excels and where it reaches its limits.
It comes into its own as soon as you replace windows in an existing building, where every opening is different. A few typical cases:
The most common case: openings from different eras, never the same dimensions. Each window is built to its measure for a clean, watertight fit.
A trapezoid under a sloping roof, a gable triangle, an arched transom: custom work hugs the openings standard ranges cannot cover.
To preserve the charm of an older home or a protected zone, we integrate glazing bars and muntins on frames with the original proportions.
For a very large glazed surface that exceeds the limits of PVC, look at custom aluminium. And to compare every material in custom work, see the overview.
In a 1930s house, not one of the eleven openings was square and two had arched transoms. We measured each bay during the survey, built eleven custom PVC windows with steel reinforcement and triple glazing, then fitted them with no rough patching.
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Custom PVC covers the vast majority of renovations. Compare it with custom aluminium for very large bays, and with the overview of custom windows in any material.
| Critère | Custom PVCVous êtes ici | Custom aluminiumVoir la gamme → | Custom (overview)Voir la gamme → |
|---|---|---|---|
| Indicative price | The gentlest | €€€ — higher | Depends on material |
| Large dimensions | Up to ≈ 2.3 m | XXL bays | All cases |
| Thermal insulation | Excellent, natural | Very good (thermal break) | Depends on material |
| Slimness of profiles | Standard | The slimmest | Variable |
| Unusual shapes | Arched, trapezoid | Arched, trapezoid | All shapes |
| Maintenance | Almost none | Almost none | Almost none |
| Ideal for | Common renovation | Very large bays | Choosing your material |
The full PVC range: profiles, glazing, performance and grants. The starting point before configuring your custom build.
See the PVC range →Custom work across all materials: how we measure, build and fit, whether in PVC, aluminium or wood.
Understand custom windows →Golden oak, anthracite, grey or two-tone foiling: add character to your custom PVC without losing its qualities.
See PVC colours →When your bay exceeds the limits of PVC, custom aluminium carries large surfaces with slim profiles.
Discover custom aluminium →Fitted price ranges by dimensions, glazing and finish, and the share covered by grants.
See PVC prices →An overview of our windows & joinery in Belgium: materials, glazing, fitting and grants on a single page.
Back to the windows guide →Custom does not cost more than a quality standard: it is the norm in renovation. The price depends on dimensions, glazing, shape and finish. Here are some pointers for fitted PVC.
See the detailed PVC price list →* Indicative ranges per fitted custom PVC window, excluding specific configurations. A costed estimate is provided with your free quote and survey.
No, not in renovation. Since an older structure is never square, almost every PVC window is already built to measure: it is the norm, not a premium option. The price depends mainly on dimensions, glazing and finish, not on the fact that the sizes are unique.
PVC alone flexes on large opening leaves. We insert a galvanised steel profile into the chamber of the frame and the leaf: it maintains alignment, rigidity and the smooth operation of the hardware over time. It is essential as soon as dimensions increase.
PVC remains ideal up to common dimensions, around 2.3 m per leaf with reinforcement. Beyond that, the weight of the glazing and the expansion of the material call for aluminium, which is stiffer. We steer you honestly during the survey, without pushing PVC where aluminium is more suitable.
Yes. Custom work allows an arched transom, an attic trapezoid, a gable triangle or an oculus. We can also integrate glazing bars or muntins to respect the character of an older or characterful facade.
Since each frame is unique, allow 4 to 6 weeks of fabrication in general after the survey and quote are validated. Fitting is then scheduled according to the number of openings; we usually replace a whole house in one to two days.
Grants depend on the performance achieved (Uw coefficient), not on the material or on being custom-made. A high-performance PVC window qualifies, depending on your region and income, for a renovation grant and 6% VAT on homes over ten years old. We handle the paperwork for you.
Free home survey to measure each opening to the millimetre, grants calculated, a single point of contact. Describe your project in under a minute.