A lean-to greenhouse is built against a wall, which saves space and lets it borrow warmth from the building — ideal for small gardens, courtyards and patios. This guide covers how to choose and site one well.
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Why choose a lean-to
- Space-saving — fits along a house or garden wall where a freestanding house won’t.
- Warmth — a sunny wall stores and releases heat, buffering temperature swings.
- Access — often placed near the house for easy year-round use.
What to check
- Wall aspect — a sunny (sun-facing) wall is best; a shaded wall limits what you can grow.
- Wall condition & fixing — the wall must take the fixings securely.
- Ventilation — lean-tos can overheat against a hot wall; ensure good roof/side vents (see ventilation).
- Glazing — glass or polycarbonate as for any greenhouse.
Lean-to greenhouses
Quick questions
Which wall is best for a lean-to greenhouse? A sunny, sun-facing wall gives the most light and warmth; avoid a permanently shaded wall.
When a lean-to is the right choice
- You have a sunny house or garden wall and limited ground space.
- You want easy, year-round access close to the house.
- You want the wall’s stored heat to buffer cold nights.
When a lean-to is a poor choice
- Only a shaded/north-facing wall is available — too little light.
- You need maximum growing volume — a freestanding house gives more.
- The wall can’t take secure fixings.
Orientation, drainage and access
Face the glazing toward the sun for winter light; guide rain away from the wall so damp doesn’t build against the house; and check the door swings clear in the space you have.
Height, ventilation and anchoring
Headroom is capped by the wall, so check the ridge height for tall plants. A lean-to traps heat against a sunny wall, so roof and side vents (or an auto opener) matter more than on a freestanding house. Anchor to both the wall and a base.