The timber dormer: every species compared

NEN-EN-350 classifies wood into five classes by natural durability against fungi and insects. Class 1 (Western Red Cedar, oak, Iroko, Teak) lasts 60+ years untreated. Class 2 (larch, Douglas, Robinia) 40-60 with minimal care. Class 3 (meranti) 25-40 with regular coating. Class 4-5 (spruce, pine) shorter; only suitable with frequent painting.

For 'set and forget' dormers pick class 1-2. Western Red Cedar (class 1) is light (380 kg/m³), dimensionally stable and may grey naturally to silver-grey — favoured for modern architecture. Oak (class 1) is heavy (700 kg/m³) but extremely durable; greys to stable silver-grey patina within 5-10 years.

Class 3-4 wood (meranti, spruce) costs less upfront but needs paint every 4-8 years (€450-€950 per cycle by painter for 3 m). Over 30 years you spend €3,500-€7,500 on painting — often more than the original purchase price.

Spruce and pine: paint every 4-6 years with primer + 2 coats opaque paint, €450-€800 per cycle by painter, €100-€200 DIY. Lifespan 25-40 years if maintenance is not skipped; one missed cycle often means rot and local panel replacement.

Meranti: 6-8 years between paint cycles. More dimensionally stable than spruce. Lifespan 30-50 years with regular care. Larch: 8-10 years; may also grey naturally to stable brown-grey. Western Red Cedar: optional coating; untreated greys gradually to silver-grey without loss of wood quality.

Oak: virtually maintenance-free but greys visibly for 5-10 years before stabilising. Optional oil treatment (€350-€650 every 5-7 years) for warm honey colour. Often required in monuments in heavy-aesthetics districts (Statenkwartier, Vughterkwartier).

Municipal aesthetics policies for monumental areas (Amsterdam centre, The Hague Statenkwartier, Den Bosch centre, Utrecht Vogelenbuurt) usually require spruce with opaque RAL paint matching the façade — to respect historical context. A timber dormer in these districts costs €10,500-€15,500 including aesthetics advice.

Modern villas (Wassenaar, Het Gooi, Bloemendaal) increasingly opt for larch or cedar with clear coating. Warm modern look matching architectural trends. Surcharge €1,500-€3,500 over spruce.

Oak chiefly on authentic rural houses (farm houses, dyke houses) and in village views in Zeeland, Friesland, Drenthe. Always request photo references from prior dormers in your municipality; this prevents aesthetics rejection.

Since 2020 some makers offer 'hybrid' dormers: PVC or aluminium element with timber exterior cladding. Combines low maintenance (no painting, no rot in the structural core) with natural look. Price close to fully timber (€8,500-€12,500 for 3 m) but lifespan can reach 60-80 years.

For sustainability and CO2: FSC- or PEFC-certified wood has far lower CO2 impact than PVC or metal. Always request supplier declaration with certification number. KOMO timber suppliers list standard; refuse if missing.

At end of life timber is largely biodegradable (if untreated or with natural paint). Paint residues with lead or older solvent coatings: hazardous waste. Disposal €150-€300 to certified depot.