Description
Evolution Four Lean‑To – 4’4″ Deep
Bright, compact and beautifully efficient — a premium cedar lean‑to greenhouse designed for smaller spaces and sheltered growing.
The Evolution Four Lean‑To is the ideal choice for gardeners who want a high‑quality cedar greenhouse that fits neatly into tighter spaces. Built from Western Red Cedar and engineered with the Evolution bar‑capping system, it offers exceptional rigidity, refined detailing and long‑term durability — all in a footprint that makes smart use of walls, courtyards and patios.
With full‑height 3mm toughened safety glass, the interior feels surprisingly bright and open. The lean‑to format naturally captures warmth from the adjoining wall, creating a stable, sheltered environment perfect for propagation, herbs, seedlings and year‑round growing.
The wall the lean‑to greenhouse is being attached to must be perfectly vertical and meet the base at a true 90‑degree angle. This ensures the rear glazing and frame sit flush against the wall, prevents gaps or pressure points, and allows the roof pitch to align correctly. If the wall leans, bows, or is out of square, the greenhouse cannot be fitted safely or weather‑tightly.
Made from Cedar
Alton Greenhouses are made from Canadian Western Red Cedar. Cedar is a very low maintenance timber, with fewer knots than Redwood or Whitewood, giving it a smoother appearance, making it ideal for painting.
Cedar has an attractive deep red colour, which silvers down over time, and contains natural oils which protect against wood rot, fungal disease & insect attack.
Cedar has higher insulative values than other timbers, and a desired service life in excess of 30 years with suitable maintenance. Alton Greenhouses are supplied treated in a clear wood preservative. We recommend that Cedar should then be treated with a solvent based wood preservative every 6 – 8 years to protect against moisture ingress.
Bar Capping
Alton’s Evolution bar‑capping system grips the glass tightly and uses it as part of the structure — eliminating rattles and dramatically increasing rigidity. Combined with thick cedar glazing bars and precision jointing, the result is a greenhouse that feels solid, quiet and built for a lifetime of growing.
Alton greenhouses come with Cedar bar capping as standard, but also offer an upgrade option to Aluminium bar capping. With this upgrade, you really can have a virtually maintenance free Cedar Greenhouse – and the stylish moss colour blends in perfectly with the Cedar as it ages to the distinctive silvery colour.
Specification
- High eaves (5’7″) for more space
- Extremely strong cedar framework
- Toughened safety glass & screw in bar capping as standard
- Sliding door with low level threshold
- Aluminium gutter plus downpipes
- Auto-vents included (see table)
- Free 10 year framework guarantee
*All sizes are approximate *
Installation & Base
Installation services are available via Bourne Buildings in some locations
Alton buildings need to be placed on a flat, level, compact (firm) base, with paving slabs or concrete being the best options. The base should be the same size as the building itself*, level (with no drainage slope) with 2 inches above ground level to avoid surface water running underneath.
Alton Greenhouses can sit on either a solid paving or concrete base as described above, or on concrete strip footing. Dwarf wall models will require a suitable dwarf wall to be constructed – Exact measurements will be supplied once you have placed an order.
Lean-to: The wall the lean‑to greenhouse is being attached to must be perfectly vertical and meet the base at a true 90‑degree angle. This ensures the rear glazing and frame sit flush against the wall, prevents gaps or pressure points, and allows the roof pitch to align correctly. If the wall leans, bows, or is out of square, the greenhouse cannot be fitted safely or weather‑tightly.
Clearance
We recommend at least 18” clearance all round for installation, airflow, and future maintenance. Victorian models: Please allow 24” clearance all round.
*Bases can be larger than the building if required by the customer but must not be any smaller.
Guarantee
Your Alton greenhouse comes with a free 10 year frame guarantee. This covers the cedar framework against faulty
manufacture. Moving parts are guaranteed for 12 months. Exclusions include : glazing, wind damage, Labour, and accidental
damage. Alton greenhouses are delivered in a totally natural cedar colour but we do factory treat with a clear wood
preservative- there is no need to re-treat it unless you particularly want to -your frame is guaranteed against rot for 10 years,
as long as you clean it once a year.