The short answer
Western red cedar and larch are the most popular, because they look natural and last well with little treatment. Composite boards need the least upkeep. Metal and fibre cement suit modern designs and rooms built close to a boundary, where fire rules can rule out timber.
Cladding is the outside skin of a garden room. It decides how the room looks from the house, how much looking after it needs, and partly how long it lasts. It is not what keeps the room warm. That job belongs to the insulation and membranes behind it.
The main types of garden room cladding
Western red cedar
Cedar is the classic choice. It is light, stable and naturally resistant to rot, so it does not need treating to last. Fresh cedar is a warm reddish brown. Left alone, it weathers to a silver grey over a year or two. If you want to keep the colour, you need to treat it regularly.
Larch
Larch is harder and usually cheaper than cedar, with a paler, more knotty look. Siberian larch grows slowly in cold climates and is denser and more durable than larch grown in the UK. Like cedar, it silvers over time if left untreated.
Thermally modified timber
This is softwood, often pine or ash, that has been heated to change its structure. The process makes it more stable and more resistant to rot, and gives it a darker, even colour. It is a good middle ground between cedar and cheaper treated softwood.
Treated softwood
Pressure-treated pine or spruce is the cheapest timber option. It works, but it moves more, can split and needs painting or staining to look good over time. It suits budget rooms better than bespoke ones.
Composite
Composite boards are made from wood fibre and plastic. They come in fixed colours and need little more than an occasional wash. They are heavier than timber, can expand and contract in heat, and some colours fade in strong sun. Quality varies a lot between brands.
Metal and fibre cement
Steel or aluminium panels give a sharp, modern look and do not rot. Fibre cement boards look like painted timber but are non-combustible. Both are popular on contemporary rooms and useful when fire rules apply (see below).
How they compare
| Cladding | Look | Upkeep | Lasts |
|---|---|---|---|
| Western red cedar | Warm, natural, silvers with age | Low if left to weather | Long |
| Siberian larch | Pale, knotty, silvers with age | Low if left to weather | Long |
| Thermally modified timber | Dark, even | Low | Long |
| Treated softwood | Plain timber | Paint or stain every few years | Medium |
| Composite | Uniform, fixed colour | Wash occasionally | Long |
| Metal or fibre cement | Modern, crisp | Very low | Long |
What it costs
Cladding is usually part of the overall price per square metre, not a separate item. Price guides show little reliable difference between composite and good timber rooms. Cedar and Siberian larch tend to cost more than treated softwood, and metal systems vary widely.
The simplest way to compare is to ask each builder to price the same room in two claddings. Our cost calculator gives the overall range for your size.
Fire rules near a boundary
This is the part people often miss. Under the building regulations, a garden room of 15 to 30 m² is only exempt from approval if it is at least 1 metre from every boundary, or built substantially of non-combustible materials.
Timber and composite are both combustible. So if you want a room of that size tight against the fence, you may need a non-combustible cladding such as metal or fibre cement, or building regulations approval. Rooms under 15 m² are usually exempt either way. Our planning guide explains the size limits in full.
Choosing the right cladding for your room
Think about three things.
How it sits with the house and garden
Timber softens a room into a garden full of planting. Dark thermally modified timber or metal suits a modern house. Composite in a grey or black looks clean but can feel flat on a traditional property.
How much upkeep you want
If you never want to pick up a brush, choose cedar or larch and let it silver, or choose composite or metal. If you want timber to keep its fresh colour, budget time each year for treatment.
Where the room sits
Close to a boundary, check the fire rule first. In a damp, shady corner, a ventilated gap behind the boards matters more than the cladding itself, because it lets the boards and frame dry out.
What to ask for in a quote
- The cladding type, grade and thickness.
- Whether there is a ventilated gap and a breathable membrane behind it.
- The fixings used. Stainless steel avoids black stains on cedar.
- How corners, door edges and the base are finished.
- Any treatment included, and what upkeep the builder recommends.
Good cladding on a poorly built frame will not last, so judge the whole room, not just the boards. If you’re comparing options for a garden room in Sheffield, mention the cladding you like in the quote form and the builder can show you samples at the visit.