Zinc and aluminium dormers

Rolled zinc (Dutch NedZink, German Rheinzink, French VMZinc) has been used on Dutch roofs since 1850. Lifespan 60-100 years in normal weather, 50-70 in coastal areas due to salt load. Colour shifts in 1-2 years from bright silver to matt grey ('patina') protecting the metal from further oxidation.

Detailing requires craftsmanship. Joints are seamed (mechanically folded) or soldered; standard screw fixings don't work due to expansion. A specialist zinc fitter costs €450-€750 per day, and a 3 m zinc dormer install takes 2-3 days. Always request photos of prior zinc dormers by the same installer, with at least 10 years standing.

Zinc prefab has existed since 2015: PVC or timber-cased elements with zinc cladding factory-applied. 1-day install, €9,500-€11,500 for 3 m. Lifespan 60 years; on-site built reaches up to 100.

Powder-coated aluminium (any RAL colour, half the weight of zinc, lower price) has been a popular alternative since 2010. Lifespan 40-60 years if powder-coated in a quality oven (180-200°C, 20 minutes); cheap coatings peel or fade in 15-20 years. Colour-stable in premium grades — ask specifically for Qualicoat class 2 or 3.

Aluminium is best when an architect wants a specific colour unavailable in zinc (red, blue, green). No patina, no colour shift over the years — what's an aesthetic quality in zinc may be a requirement in aluminium (think colour matching to existing façade).

Maintenance: virtually nil for first 25-30 years. After that optional polishing or re-coating (€450-€900 for 3 m), extending life 15-25 years. Aluminium is 100% recyclable and needs only 5% of the energy to recycle vs producing new aluminium.

For modern architecture with flat roofs and crisp detailing: cubic volumes, seamless transitions between façade and dormer. Aluminium and zinc give an industrial, contemporary feel unachievable with PVC or timber.

As deliberate accents on pre-war villas: a zinc dormer as modern accent in an old façade. Works mainly when architect and aesthetics committee agree on clear material/style contrast. Always pre-consult; rejection costs 3-6 months delay.

In very wet climates (Twente, South Limburg, coastal area) where PVC sealants risk leaks after 15-20 years. Zinc and aluminium have no exterior sealant joints; seam-leak risk is negligible.

In protected village views and monuments with traditional looks: aesthetics nearly always rejects metal. The Hague Statenkwartier, Amsterdam centre, Vughterkwartier, Utrecht Vogelenbuurt — timber (spruce with opaque paint or oak) is required.

Limited budget: a €1,500-€3,500 premium over PVC or timber isn't justified for many owners. Functionally a quality prefab PVC (KOMO with heat-block) is just as watertight and well-insulated.

Installing on old houses with light roof framing: zinc is heavier than PVC (550-750 kg vs 450-650 for 3 m), structural review required. Reinforcement surcharge €450-€1,200.