Alton Cedar Greenhouses Where to buy
An Alton half boarded Victorian cedar greenhouse surrounded by roses, foxgloves and delphiniums

Made in the UK · Season 2026

Over 100 years of cedar greenhouses

Crafted in our own Staffordshire workshop from Western Red Cedar, and built to last a lifetime.

A whole concept for a cedar greenhouse

Since 1921, Alton has been at the forefront of the cedar greenhouse market. The iconic sloping-sided Amateur greenhouse led the market for decades, and since then the Alton design team have pooled their knowledge, experience and years of customer feedback to create a cedar greenhouse fit for the 21st century.

Every piece of cedar is machined in-house in our Staffordshire workshop — some machines have been reliably making Alton greenhouses for over 40 years, alongside modern CNC equipment for highly accurate results. Each model is delivered flat-packed, which cuts handling and storage costs so you get more greenhouse for your money.

Why Alton is stronger

Every detail is designed to make the frame stronger, keep water off the wood, and give your plants a better place to grow.

A stronger frame

More wood
Glazing bars based on 44×44mm timbers, and 44×69mm in places, where many greenhouses have grown thinner to save cost.
Mortice and tenon joints
Make assembly straightforward and add strength to the framework.
Bar capping system
Grips the glass tightly instead of a beading or groove, so the glass adds to the frame's strength, with no rattling.
Toughened safety glass
3mm as standard, 5–7 times stronger than horticultural glass, in large rigid panes.

Built to resist rot

Metal base included
Keeps the cedar off damp ground, with the glass sitting on the base so no run-off reaches the wood. On every Evolution, lean-to and octagonal model.
Glass overhangs the gutter
Roof water runs straight off the glass into the gutter, never over the wood.
Guttering and downpipes
Full-length aluminium gutters keep water away from the frame and let you collect it.

Better to grow in

High eaves
5′7″, up to 18″ higher than the lowest on the market, for more air, more headroom and room for a high-level shelf.
Auto-vents and louvres
Every roof vent has an automatic opener as standard. Louvres draw in cool air as the vents release warm air, manual as standard with automatic openers available.
No step at the door
A low-profile threshold, with 4′ wide double doors on models 8′ wide and above, ideal for a wheelbarrow or wheelchair.

The Alton range

Choose your style to see the sizes available.

Alton Evolution Six cedar greenhouse in a garden

Evolution greenhouses

The classic Alton freestanding greenhouse. The Eight, Ten and Twelve extend to any length in 2′ increments, and can take an internal partition with a sliding door.

Model Width Lengths Door
Five → 1.68m (5′6″) 4′5″ to 12′9″ Single sliding
Six → 1.98m (6′6″) 4′5″ to 12′9″ Single sliding
Eight → 2.62m (8′7″) From 6′6″, any length 4′ double
Ten → 3.24m (10′8″) From 6′6″, any length 4′ double
Twelve → 3.87m (12′9″) From 6′6″, any length 4′ double

Victorian greenhouses

Add a real centrepiece to your garden. The Alton Victorian range blends the benefits of modern design with a distinctly Victorian image — a 45° roof pitch, cast aluminium spandrels and finials, a Victorian-style gutter, and thicker 44×69mm roof timbers throughout.

Alton Cambridge half boarded Victorian greenhouse

Half boarded (HB)

Cedar boarding to the lower walls.

Alton Elmhurst low wall Victorian greenhouse

Low wall (LW)

Built onto a brick or stone dwarf wall.

Alton Harrow glass to ground Victorian greenhouse

Glass to ground (GG)

Maximum light, right down to the base.

Width Lengths Half boarded Low wall Glass to ground
1.9m (6′2″) 4′4″ to 12′7″ Denstone Eton Smallwood
2.25m (7′5″) From 8′5″, any length Durham Ewell —
2.65m (8′8″) From 6′6″, any length Cheltenham Ellesmere Harrow
3.07m (9′11″) From 8′5″, any length Cambridge Elmhurst —
3.27m (10′9″) From 6′5″, any length Westminster Oakham Lancing

Models 7′5″ wide and above extend to any length. Optional cast aluminium cresting is available.

Alton Evolution Six-LT lean-to greenhouse

Lean-to greenhouses

All the Evolution features in a greenhouse built against a wall, with automatic roof vents and louvres as standard. Extensions are available for longer runs.

Model Depth Lengths
Four-LT → 1.33m (4′4″) 4′5″ to 12′9″, extendable
Six-LT → 1.96m (6′6″) 4′5″ to 12′9″, extendable
Alton Fusion combined cedar workshop and greenhouse

Fusion workshop & greenhouse

A cedar-clad workshop with a lockable hinged door, Thermowood floor and felt roof, combined with an all-cedar greenhouse with a sliding door. Saves space without compromising on either.

Model Width Lengths
Fusion 8 → 2.68m (8′9″) 6′6″ to 12′9″
Fusion 10 → 3.31m (10′10″) 6′6″ to 12′9″
Alton Evolution Octagonal cedar greenhouse

Octagonal greenhouses

A striking centrepiece for any garden, with a locking door, louvres and an integral metal base plinth.

Size Width Automatic roof vents
6×6 → 1.99m (6′6″) None (louvres only)
6×9 2.80m (9′2″) 2
9×9 2.80m (9′2″) 2
9×12 3.61m (11′10″) 2
Alton Evolution cedar cold frame with moss aluminium capping

Evolution cold frames

The ideal way to harden off plants before planting out. Made from the same thick cedar profiles as the Evolution greenhouses, with toughened glass, a metal base plinth, and lids that hinge, slide or lift off completely.

Version Size Best for
Cedar capping → 4′×2′ Natural timber look; takes the optional cedar boarding kit
Aluminium capping → 4′×2′ Lower maintenance, powder coated in moss

Why Western Red Cedar?

Famed for its extraordinary durability, Western Red Cedar is saturated with natural preservative oils that make it virtually immune to decay. It doesn't shrink, swell or warp excessively, it insulates well, and its aroma deters insects and pests.

A 12-month study comparing cedar with aluminium found the Alton grew heavier crops — 12lb more tomatoes — with less leaf curl, less watering, and 18% less electricity to heat.

Do I need to treat it?

No. Your Alton is supplied in natural cedar, factory treated with a clear wood preservative, and simply mellows to a silvery grey that the moss-coloured metalwork complements perfectly. Customers often tell us about their 30-year-old Alton.

The only maintenance we recommend is a clean once a year, ideally in January or February, ready for the growing season.

Upgrade: aluminium bar capping

Every Alton comes with a cedar capping system as standard. Upgrade to aluminium capping, powder coated in moss with air-cushioned rubber seals, for a virtually maintenance-free cedar greenhouse that blends in as the timber ages to silver.

Assembly

Alton greenhouses are delivered as a flat-packed kit for self-assembly. No joinery skills are needed — all the cutting and jointing is done in the factory, so it's a question of slotting together and screwing. We do recommend an experienced greenhouse fitter, which your retailer can arrange.

10 year frame guarantee

Every Alton comes with a free 10 year guarantee covering the cedar framework against faulty manufacture and rot — with no need to re-treat, as long as you clean it once a year. Moving parts are guaranteed for 12 months.

Exclusions include glazing, wind damage, labour and accidental damage.

Where to buy

The full Alton range is available from The Greenhouse People, with sizes, options and prices for every model.

Shop Alton at Greenhouse People →