Garden Room Cladding: Cedar vs Composite vs Larch vs Render

The garden room cladding you choose sets the look of the building and, just as importantly, decides how much time and money you will spend maintaining it for the next twenty years. The frame and insulation keep a garden room warm, but the cladding is the weather skin and the face the building shows to the garden. This guide compares the main options: western red cedar, larch, composite and render, with the honest trade-offs on cost, maintenance and lifespan, so you can spec a finish you will still be happy with well after the novelty wears off.

Western red cedar

Cedar is the classic garden room cladding, and for good reason. It has a rich, warm colour when new, a beautiful natural grain, and is naturally durable thanks to oils in the timber that resist rot and insects. It is lightweight and stable, so it sits well on a timber-framed building.

The catch is the way it ages. Left untreated, cedar silvers to a soft grey, often within the first year, as the sun bleaches the surface. Many owners love the silvered look; others do not and have to re-oil regularly to hold the honey tone, which is ongoing work. As a rough guide, cedar cladding fitted costs in the region of £165 per square metre. Choose cedar if you want a premium natural finish and either embrace the grey or accept the upkeep to keep it golden.

Larch and thermally modified timber

Larch is a harder, denser softwood that offers much of the natural-timber appeal at a lower price than cedar, around £115 per square metre fitted. Siberian larch in particular is tough and long lasting. Like cedar, untreated larch will silver over time unless it is oiled.

Thermally modified timber, often sold as Thermowood, is worth knowing about here. The wood is heat-treated to make it far more stable and rot-resistant, and it needs no painting or staining to survive. Manufacturers quote service lives measured in decades. It is a strong middle ground: a real-timber look with less maintenance than raw cedar or larch, though it too will grey if left uncoated.

Composite cladding

Composite cladding is made from a blend of wood fibre and recycled plastic, engineered to look like timber while behaving like plastic. Its big selling point is maintenance: beyond an occasional wash, there is essentially nothing to do, no painting, staining or annual preservation. It holds its colour rather than silvering, resists rot and moisture, and shrugs off the British weather.

The trade-offs are cost and authenticity. Composite typically costs more upfront than larch, and while modern boards look convincing, a keen eye can tell it from real cedar up close. For anyone who wants a smart finish and simply does not want to think about cladding again, composite is often the most sensible long-term choice.

Render and render board

Render gives a garden room a crisp, contemporary, house-like appearance that suits modern designs and pale colour schemes. On a garden room it is usually a thin coat applied over a render-carrier board rather than traditional sand and cement, which keeps weight down and reduces cracking. Acrylic and silicone renders are flexible and come pre-coloured, so there is no repainting.

Render works well as a contrast to timber, for example a rendered main body with a cedar or composite feature panel. It is durable but can be marked or chipped by knocks at low level, and any repair needs to blend into the surrounding finish, so it is less forgiving than a board you can simply swap.

Other options worth knowing

Fibre cement boards: flat or woodgrain-effect panels that are fireproof, rot-proof and very low maintenance, popular for a clean modern look.
Painted timber or plywood: smooth boards finished in a bold colour, striking when new but needing repainting to stay sharp.
Mixed cladding: combining materials, such as vertical cedar with a rendered or dark composite section, to add interest and break up a large elevation.

Cost and maintenance at a glance

Bringing the main options together:

Larch: lowest natural-timber cost, around £115 per square metre; silvers unless oiled.
Cedar: premium natural look, around £165 per square metre; silvers fast, re-oil to keep the colour.
Thermowood: mid-range, low maintenance for a real-timber finish; greys if left uncoated.
Composite: higher upfront cost, effectively no maintenance and keeps its colour.
Render: contemporary finish, no repainting with modern renders, but harder to repair invisibly.

For a wider view of build costs and how cladding fits the overall budget, the Checkatrade cladding cost guide is a useful reference.

How to choose the right cladding

Work back from how much maintenance you are realistically willing to do. If you want a natural timber look and enjoy the odd weekend of oiling, cedar or larch reward the effort. If you would rather never touch it again, composite, Thermowood or fibre cement are the low-effort routes. Match the finish to your house and garden too: render and dark composite read as modern, while cedar and larch soften a building into a planted garden. Finally, check what your supplier includes as standard, since upgrading from a basic softwood to cedar or composite is one of the more common ways a quote climbs. Our garden room guides cover construction, insulation and costs to help you spec the whole build, not just the skin.

Fixing, orientation and detailing

The material is only half the story. How cladding is fitted decides whether it lasts and stays looking good.

Orientation. Horizontal boards give a long, low, contemporary look and are the most common. Vertical cladding sheds water quickly and suits a taller, more traditional feel. Both work; it is a design choice.
Ventilation gap. Good installers fix timber and composite over battens so air can circulate behind the boards. That drying gap is what stops moisture being trapped against the structure and causing rot.
Fixings. Stainless steel or other non-corroding fixings matter, especially with cedar, whose natural oils can react with cheaper fasteners and leave dark streaks.
Corners and trims. Neat corner details, window reveals and a clean base line where the cladding meets the ground lift the finish and keep water out of vulnerable edges.

When you compare quotes, ask how the cladding is fixed and ventilated, not just which timber is used. Good detailing is often the difference between a building that still looks smart in ten years and one that does not.

Frequently asked questions

What is the best cladding for a garden room?

There is no single best. Cedar and larch give the most natural timber look, composite and Thermowood are the lowest maintenance, and render suits modern designs. The right choice depends on how much upkeep you want and the style of your home and garden.

Does cedar cladding need maintenance?

Cedar is naturally rot-resistant so it will last untreated, but it silvers to grey quickly, often within a year. If you want to keep the warm golden colour you need to re-oil it regularly, which is ongoing work.

Is composite cladding better than timber?

For maintenance, yes. Composite needs little more than an occasional clean, keeps its colour and resists rot. Timber looks more authentic and can cost less upfront, but needs treating to stay at its best, so composite often wins over the long term.

How much does garden room cladding cost?

As a guide, larch is around £115 per square metre fitted and cedar around £165 per square metre. Composite usually costs more upfront than larch but saves on maintenance, while render pricing depends on the board system and finish.

Can you mix cladding materials on a garden room?

Yes, and it is popular. Combining materials such as vertical cedar with a rendered or dark composite section adds visual interest and breaks up a large elevation, while letting you put the toughest, lowest-maintenance material where it takes the most wear.