The PVC dormer: 2026 technical guide
PVC is not a monolithic term: it covers extruded PVC, HPL sheet (Trespa, Kerlite-types) and composite (fibre-reinforced PVC). Each has its own strengths, price points and lifespan. A 3 m prefab PVC dormer in 2026 costs €5,500-€8,500 including 1-day install — by far the largest market share (around 70% of all new dormers in the Netherlands). This guide explains which PVC suits when, how long it lasts, real 30-year maintenance costs and pitfalls to know before signing.
- Price prefab 3 m
- €5,500 – €8,500
- KOMO-PVC lifespan
- 30 – 40 years
- HPL lifespan
- 40 – 50 years
- 30-year maintenance
- €500 – €1,200
- Market share NL
- ~70%
- PVC recyclability
- 100% (separated)
- Standard warranty
- 10 – 15 years material
PVC, HPL and composite: what's the difference?
Extruded PVC is the workhorse. The frame is pressed as one hollow profile from the extruder and reinforced with steel or aluminium for stiffness. Pros: lowest material cost (€350-€600 per finished m² façade), good insulation in the frame profile (Uf 1.2-1.4 W/m²K), easy to clean. Cons: expansion sensitivity at dark colours in full sun, low scratch resistance on flat panels.
HPL (High Pressure Laminate, brands Trespa, Kerlite) is a high-pressure, high-temperature press of paper fibres and resin. Far harder than PVC, scratch-resistant, through-coloured so damage shows little, and available in nearly any colour or print (including wood-grain). Surcharge €800-€2,000 over standard PVC for 3 m.
Composite is PVC reinforced with glass or natural-fibre panels. Combines lower price of PVC with better dimensional stability and hardness. Sits between PVC and HPL in properties and price (€400-€900 above standard PVC). Less known but growing since 2022.
Heat behaviour and colour choice: the 70°C threshold
Dark PVC colours (anthracite RAL 7016, black RAL 9005, dark grey) reach 70-80°C surface temperature in full sun. Cheap PVC without heat stabiliser may warp, lose gloss or even delaminate in layered panels. For anthracite and black, serious makers require 'heat-block' PVC (with TiO2/CaCO3 additives) or HPL with UV coating.
Ask the quote to specify the colour category. A statement like 'KOMO BRL 0703 with cool-colour additive' or 'HPL EN 438-7 Class 3' gives certainty. Without it you risk visible warp within 5-10 years on dark colours.
Light colours (white RAL 9010, cream RAL 9001, light grey) don't have this issue. Standard PVC is fully reliable there and the heat-block surcharge is unnecessary. White RAL 9010 on south-facing dormers stays below 45°C.
Lifespan and 30-year lifecycle costs
KOMO-certified PVC with heat-block and UV stabilisation lasts 30-40 years in Dutch weather. HPL (Trespa) holds 40-50 years without significant discolouration. Cheap non-KOMO PVC can yellow and fade within 12-18 years — especially on south-facing façades.
30-year maintenance on KOMO PVC: €500-€1,200 total. Includes 1-2 light cleans per year (DIY €0, window cleaner €150-€300 per visit), sealant replacement after 15-20 years (€350-€650), possible lead reflashing after 15 years (€450-€900). For comparison: timber needs €4,500-€7,500 over 30 years for paint and wood care.
At end of life, full replacement (€5,500-€8,500 new element) usually beats stacked repairs. PVC is 100% recyclable when separated; many makers (Inoutic, Schüco, Profine) have run take-back schemes since 2020 with €0-€150 compensation.
Three common pitfalls
Pitfall 1: soft PVC that ripples or bows in hot summers. Especially dark colours without heat-block, or cheap import PVC without KOMO. Always demand KOMO certificate and PVC supplier spec (Inoutic, Schüco, Profine, Veka are reliable).
Pitfall 2: too-thin cheek cladding (< 16 mm) so the batten imprint shows through after a few years. Demand at least 18-24 mm cheek cladding, and for HPL at least 8 mm sheet on aluminium subframe.
Pitfall 3: upper ventilation openings that don't lie flat on the pitched roof, causing water ingress. Ask for handover photos of the top connection and lead finish; demand a handover report with photo documentation. If unsure: have a roofer do a second opinion (€150-€250).
FAQ
- How long does a PVC dormer really last?
- KOMO-certified PVC: 30-40 years. HPL: 40-50 years. Cheap non-KOMO PVC without UV stabilisation can yellow within 12-18 years. Always demand KOMO certificate.
- Is PVC repairable?
- Limited. Small scratches polish out with PVC polish (€15). Larger impact damage needs panel replacement (€450-€900 per panel). Timber is more repairable but needs far more maintenance.
- Can I pick any colour?
- Light colours (white, cream, light grey): standard PVC is fine. Dark colours (anthracite, black): demand heat-block PVC or HPL with UV coating, otherwise risk of warping in 5-10 years.
- What's the price difference between PVC and HPL?
- HPL is €800-€2,000 more for a 3 m dormer. In return you get scratch resistance, colour stability and 40-50 year lifespan instead of 30-40.
- Is PVC eco-friendly?
- 100% recyclable when separated. Many makers (Inoutic, Schüco, Profine, Veka) run take-back schemes since 2020. Higher CO2 footprint in production than timber, but long lifespan compensates.