Cladding is the single most visible decision on any garden room. It sets the tone of the building, drives a meaningful chunk of the cost, and — critically — determines how the room will look in five, ten and twenty years. Every Arden & Oak build carries a full ventilated cavity behind the cladding, so all four options below sit on the same high-spec sub-structure.
Western Red Cedar
The classic modern-garden-room material. Beautifully grained, warm honey tone when new, silvers to a soft grey over 2–4 years if left untreated. Naturally durable — cedar's own oils resist decay without preservative. Best for buyers who want warmth on day one and don't mind (or actively want) the silvered patina.
Expected life
40+ years untreated, longer if maintained with a UV-blocking oil every 3–5 years.
Thermowood
European softwood kiln-treated at ~215°C to permanently drive out moisture and sugars. The heat treatment darkens the timber to a rich chocolate-brown and dramatically improves stability and rot resistance. Cheaper than cedar and Accoya, and doesn't need a treatment schedule. Silvers similarly to cedar over 2–4 years.
Expected life
30+ years untreated, functionally the sweet spot on cost-per-year.
Accoya
Acetylated softwood — the timber cells are permanently modified so they can no longer absorb water. Genuinely dimensionally stable, virtually rot-proof, and machined to very tight tolerances. The premium option for buyers who want a crisp, straight-line modernist aesthetic that stays looking sharp for decades.
Expected life
50+ years, with a 25-year manufacturer guarantee against rot.
Charred timber (Shou Sugi Ban)
Traditionally-Japanese, dramatically contemporary. Timber is deliberately charred to seal the surface with a stable layer of carbon, then finished with a natural oil. Deep matte black with a subtle textured grain — striking against green planting, unforgiving of a badly kept garden. Not everyone's taste; on the right building, exceptional.
Expected life
40+ years. Colour is highly stable — no silvering.
Which one to pick
- Budget-first, low-maintenance: Thermowood
- Warm, mid-priced classic: Western Red Cedar
- Long-term architectural sharpness: Accoya
- Strong design statement: Charred timber