🌲 Best Materials for Outdoor Buildings and Garden Structures
A complete guide from Nest Treehouses
When you’re building something outdoors — whether it’s a treehouse, a garden room, a cabin, a pergola, or a climbing frame — the materials you choose matter just as much as the design. Outdoor structures live in the real world: rain, wind, sun, frost, insects, and the occasional football flying across the garden.
At Nest Treehouses, we’ve spent years designing and building bespoke outdoor structures across the UK, from Sussex woodlands to coastal sites and rural estates. Over time, we’ve learned exactly which materials stand the test of time — and which ones don’t.
This guide walks you through the best materials for outdoor buildings and garden structures, why we use them, and how they affect durability, appearance, and long‑term maintenance.
🌿 What Makes a Material “Good” for Outdoor Use?
Before we dive into specific materials, it’s worth understanding what makes something suitable for outdoor construction.
The best outdoor materials are:
1. Weather‑resistant
They can handle rain, frost, UV exposure, and temperature changes.
2. Durable
They last for years without warping, rotting, or splitting.
3. Low‑maintenance
You shouldn’t need to constantly treat or repair them.
4. Safe
Especially important for children’s play structures and elevated builds.
5. Sustainable
Responsibly sourced timber and eco‑friendly finishes matter.
6. Beautiful
Outdoor structures should complement the landscape, not fight against it.
We choose materials that tick all of these boxes.
🪵 The Best Timber for Outdoor Buildings
Timber is at the heart of almost everything we build. But not all wood is created equal — and choosing the right species makes a huge difference.
Here are the timbers we trust most.
🌲 1. Cedar (Western Red Cedar)
Best for: Cladding, façades, decorative finishes Why we love it:
Naturally rot‑resistant
Beautiful colour and grain
Low‑maintenance
Lightweight but strong
Ages to a stunning silver‑grey
Cedar is one of the most premium timbers for outdoor use. It’s ideal for treehouses, cabins, and garden rooms where appearance matters.
🌳 2. Larch (Siberian or British)
Best for: Cladding, structural elements Why we love it:
Very durable
High resin content (natural protection)
Strong and stable
More affordable than cedar
Larch is a fantastic balance of beauty, strength, and value.
🌲 3. Douglas Fir
Best for: Structural beams, posts, frames Why we love it:
Extremely strong
Excellent load‑bearing properties
Great for large spans
Takes stain beautifully
We often use Douglas Fir for the main structural skeleton of a treehouse or cabin.
🌳 4. Pressure‑Treated Softwood
Best for: Sub‑structures, posts, decking frames Why we use it:
Affordable
Long‑lasting
Resistant to rot and insects
Ideal for hidden structural elements
It’s not the prettiest timber, but it’s incredibly practical.
🌿 5. Oak
Best for: Premium finishes, feature beams, heritage projects Why we love it:
Incredibly strong
Beautiful grain
Ages gracefully
Perfect for luxury builds
Oak is a premium choice and adds a sense of craftsmanship and permanence.
🧱 Best Materials for Cladding and Exterior Finishes
Your cladding determines how your structure looks — and how well it stands up to the elements.
Here are the top options.
🪵 1. Cedar Cladding
Premium, beautiful, and naturally weather‑resistant. Ideal for luxury treehouses, cabins, and garden rooms.
🌲 2. Larch Cladding
A more affordable alternative to cedar with excellent durability.
🧱 3. Thermowood
Heat‑treated timber that becomes:
More stable
More durable
More resistant to moisture
It’s a great eco‑friendly option.
🪨 4. Composite Cladding
Made from recycled wood fibres and polymers.
Pros:
Very low maintenance
Long lifespan
Consistent appearance
Cons:
Less natural look
Not suitable for all designs
We use it selectively depending on the project.
🏠Best Roofing Materials for Outdoor Buildings
Roofing is one of the most important decisions — it protects everything beneath it.
Here are the materials we trust.
🪵 1. Cedar Shingles
Best for: Treehouses, cabins, woodland structures Why we love them:
Beautiful natural look
Lightweight
Long‑lasting
Perfect for blending into woodland settings
They’re a favourite for premium builds.
🧱 2. EPDM Rubber Roofing
Best for: Garden rooms, flat roofs Why we use it:
Extremely durable
Waterproof
Low maintenance
Ideal for modern designs
It’s not visible from the ground, so it’s a practical choice.
🪨 3. Metal Roofing (Steel or Aluminium)
Best for: Contemporary cabins, commercial structures Why we like it:
Very long lifespan
Fire‑resistant
Strong and lightweight
Modern aesthetic
It’s becoming increasingly popular for high‑end outdoor buildings.
🪵 4. Felt Roofing (High‑Performance)
Best for: Budget‑friendly builds Why we use it:
Affordable
Quick to install
Suitable for small structures
We only use high‑quality felt designed for long‑term outdoor use.
🪟 Best Materials for Windows and Doors
Outdoor buildings need windows and doors that can handle the weather.
🪵 1. Timber Frames
Beautiful, natural, and perfect for woodland settings.
🪟 2. Aluminium Frames
Modern, slimline, and extremely durable.
🧊 3. Double or Triple Glazing
Essential for:
Garden offices
Cabins
Commercial accommodation
It improves insulation and comfort.
🧱 Best Materials for Foundations and Supports
Treehouses and elevated structures require specialist foundations.
Here’s what we use.
🪵 1. Timber Posts
Pressure‑treated or Douglas Fir posts are ideal for:
Low‑level structures
Play areas
Garden buildings
🪨 2. Ground Screws
A fantastic eco‑friendly alternative to concrete.
Benefits:
Minimal ground disturbance
Fast installation
Reversible
Strong and stable
We use ground screws often for garden rooms and cabins.
🧱 3. Steel Brackets and Fixings
Essential for:
Elevated platforms
Rope bridges
Heavy loads
Commercial structures
We use high‑grade galvanised or stainless steel.
🧒 Best Materials for Climbing Frames and Play Structures
Safety is everything when building for children.
We use:
Smooth, planed timber
Child‑safe finishes
Anti‑slip decking
Rope rated for outdoor use
Stainless steel fixings
UV‑resistant plastics
Every material is chosen with durability and safety in mind.
🌍 Sustainable and Eco‑Friendly Materials
We prioritise sustainability wherever possible.
This includes:
FSC‑certified timber
Low‑VOC finishes
Recycled composite materials
Ground screws instead of concrete
Natural oils and stains
Outdoor buildings should enhance nature, not harm it.
🧰 What Materials Do We Recommend for Each Structure?
Here’s a quick guide.
🌳 Treehouses
Cedar or larch cladding
Douglas Fir structure
Cedar shingles
Timber windows and doors
Stainless steel fixings
🏡 Garden Rooms
Cedar, larch, or composite cladding
EPDM roofing
Aluminium or timber windows
Ground screws or timber foundations
🏕️ Cabins
Larch or cedar cladding
Metal or shingle roofing
Insulated walls
Double glazing
🧒 Climbing Frames
Smooth, planed softwood
Anti‑slip decking
Stainless steel fixings
UV‑resistant rope