Dormer frames: PVC, wood or aluminium
The frame is the most expensive and visually defining part of your dormer's façade. Material choice drives price (up to €2,500 spread per dormer), maintenance (0 to 8 hours per year), insulation (Uf 0.9 to 2.2 W/m²K) and appearance. In protected cityscapes (welstand) wood is often mandatory; in new-build areas PVC is standard. Below the factual differences for 2026.
- PVC Uf
- 1.1–1.3 W/m²K
- Wood Uf (meranti/accoya)
- 1.3–1.6 W/m²K
- Aluminium Uf (thermally broken)
- 1.4–2.0 W/m²K
- PVC lifespan
- 35–50 years
- Accoya wood lifespan
- 50+ years
- PVC maintenance
- Cleaning only, no painting
PVC — the market standard
About 80% of new dormers in the Netherlands get PVC frames because of lowest lifetime cost. A 3-metre dormer with PVC frames costs €6,500–€8,500; in wood €8,500–€11,500.
Modern PVC profiles are 6- or 7-chamber, typically Kömmerling, Schüco, Veka or Deceuninck. Standard with steel reinforcement, RAL-certified glass, tilt-and-turn hardware. White is standard; anthracite (RAL 7016) and black add €400–€700 due to foiled profile.
Important: PVC expands in heat. Dark colours on south-facing dormers can reach 70°C — choose aluminium-clad coatings (e.g. AluClip, CoEx) to prevent warping.
Wood — required in protected areas
In protected city- and village views, welstand almost always requires wooden frames in the original profile. Meranti is standard (€1,500–€2,500 surcharge on a 3-metre dormer); accoya (modified FSC wood) costs more but lasts 50+ years with minimal maintenance.
Wood needs repainting every 6–8 years (opaque) or staining every 4 years (transparent). Budget €600–€1,200 per repaint for a 3-metre dormer. Neglect causes sill rot within 10–15 years — replacement is €800–€1,500 per frame.
Aluminium — for sleek architecture
Aluminium is mainly used for modern architecture and large glass surfaces (>2.5 m wide in one door). Advantage: slimmer profiles (sightline 70 mm vs 110 mm in PVC), more stable at large sizes. Downside: higher price (€2,000–€3,500 extra) and worse Uf unless you choose systems with >34 mm thermal break.
Schüco AWS 75 and Reynaers MasterLine 8 are market standards. Always demand the Uf value on the signed quote; cheap non-broken aluminium hits Uf 3.0 W/m²K and fails Bouwbesluit 2026.
Hardware, ventilation and pitfalls
Standard hardware is tilt-and-turn, burglar resistance class 2 per NEN 5096 (PKVW certificate). Class 3 (SKG***) adds €80–€150 per frame and is mandatory in BORG-secured properties.
Top-mounted ventilation grilles are mandatory (Bouwbesluit section 3.6); self-regulating type at max 1.0 dm³/s.m². Ask for acoustic 'suskast' grilles on south-facing dormers near busy roads — €60–€120 extra per grille.
Pitfall: 'free upgrade to HR++ glass' in offers. HR++ has been the minimum since 2021 — it's no upgrade. Request HR+++ (triple, Ug 0.6 W/m²K) for BENG-level performance; €120–€180/m² glass extra.
FAQ
- What does a PVC vs wooden frame set cost for 3 metres?
- PVC: €2,800–€3,800 incl. glass and installation. Meranti: €4,500–€6,000. Accoya: €5,500–€7,500. Aluminium: €5,000–€7,000.
- How long does a PVC frame last?
- 35–50 years in white. Dark colours (anthracite, black) on south side average 25–35 years due to UV and thermal stress. Glass usually needs replacement earlier (after 20–25 years HR++ slowly loses its gas filling).
- Must I choose wood for a pre-war house?
- Not always. Outside protected views, PVC or aluminium is allowed if welstand approves the profile. Request a welstand advice from your municipality beforehand; criteria vary by town.
- What's the difference between Uw and Uf?
- Uf is insulation of the frame profile only; Ug of the glass; Uw is the weighted average of the whole window including spacers. Bouwbesluit 2026 requires Uw ≤ 1.65 W/m²K.
- Do I get warranty on frames?
- Standard 10-year factory warranty on PVC profiles (warping, discolouration); 5 years on hardware; 10 years on HR++ glass (gas filling). Wood: typically 6 years on construction. Read terms before signing — some warranties void without annual maintenance.