The best lean-to greenhouses for UK walls

Six lean-tos compared

These six cover the walls most people have: tall house walls, narrow side returns, low bungalow eaves and small patios. For freestanding houses, see the rest of our greenhouse buying guides. Figures are from the retailer's specification tables (Gardensite, October 2026); sizes are width x depth as listed by Gardensite, and heights are external.

All six are listed as available to order. Price ranges cover the cheapest and dearest standard versions (frame colour, glazing or solid back) before bases and accessories. Gardensite lists the Palram and Forest with the long side as the depth, the other way round from the Elite and Vitavia models, so check the maker's plan for which side goes against the wall.

Start with the wall: clear height decides the shortlist

A lean-to's ridge sits against your wall, so the tallest point of the greenhouse has to fit under whatever is lowest on that wall: a window sill, a gutter, a soffit or a vent. Greenhouse Stores' advice is to measure the clear wall height and depth first and to rule out any model taller than that, and to look at low models where windows or bungalow eaves limit the ridge.

Remember to add the base. The Elite Kensington's optional base adds 12.8cm, and Gardensite says the house sits about 5 inches too low without one. Vitavia's steel base frames add about 60mm.

A worked example. Say the underside of your gutter is 2.3m above the ground where the greenhouse will stand:

• Elite Kensington: 240cm to the ridge before any base. Does not fit.
• Vitavia Ida 5200 or 3300: 222cm, about 228cm with the steel base. Fits with almost nothing to spare, which leaves little room for the flashing along the top.
• Palram Hybrid 4x8: 225cm. Tight in the same way. Gardensite gives only an external height and does not say whether it includes the base that comes with it.
• Forest Wallscape 4x8: 205.9cm. Fits with room for fixings and flashing.

If your wall is a full storey high with nothing in the way, height stops being the limit and depth and glazing decide it.

Which way the wall faces

Hartley Botanic recommends a south-facing wall, either a garden wall or the house, for the most sunlight, away from tall trees. Greenhouse Stores says south and west walls usually give the strongest growing light, an east wall suits morning sun, and a north-facing spot needs careful choice of crops and glazing.

The catch with a sunny wall is summer heat. In a DIYnot thread on whether a lean-to can damage house brickwork, posters' main concern was heat: one warned it would "make the wall very hot in summer", and another that it could heat the section of wall inside the greenhouse, depending on the wall and the size of the greenhouse. Every pick here has just one roof vent as standard (the Elite adds a side louvre), so on a south or west wall budget for an automatic vent opener: Gardensite lists them at about £32–£38 for the Elite and Vitavia models, including the Elite's louvre opener, and £44.99 for the Palram.

Our polycarbonate vs glass comparison explains how twin-wall polycarbonate diffuses light and holds heat compared with glass.

Depth: 2ft, 4ft or 6ft

• About 2ft deep (Ida 900): shelves and pots only. Gardensite gives the Ida 900 a growing area of 0.9 square metres. You stand outside it and reach in.
• About 4ft deep (Ida 3300; the Palram Hybrid and Forest Wallscape are about 4ft by 8ft, but check which way round they fit): a narrow path with a bed or staging along one side. Good for tomatoes and peppers, which Hartley Botanic suggests training up the back wall.
• About 6ft deep (Elite Kensington, Ida 5200): room for staging on the front and a border against the wall, and space to work inside.

Check the door too. The Ida 3300 has double doors across the front and the Ida 5200 double sliding doors, both 122cm wide, while the Palram (56cm), Forest (54.5cm) and Elite as standard (60cm) have a single narrow door.

Fixing it to the wall and keeping damp out

None of the retailer pages we checked gives wall fixing details; Gardensite notes a wall mounting kit with the Palram, and the rest are covered in the makers' instructions. Greenhouse Stores' general advice is worth following whichever you buy:

• Follow the maker's instructions and use fixings suitable for your wall. Uneven render or pebbledash may need a batten first.
• Seal the top of the lean-to to the house with lead or proprietary flashing tucked into a chase or under render, not silicone alone on the brick face.
• Seal every hole drilled into a cavity wall, and keep the lean-to's gutter clear of the house damp-proof course.
• Get the base level and square before glazing. A small fall can open a gap at the flashing.

The base

A lean-to needs the same level, solid base as any greenhouse, plus a straight line along the wall. The Palram Hybrid comes with a galvanised steel base; the Elite and Vitavia bases are optional extras that also raise the house; the Forest Wallscape has no floor, for drainage. Our greenhouse base guide covers slabs, concrete and steel frames.

Glazing next to a house

Gardensite's Elite listing says 3mm horticultural glass is not recommended where children or pets are about, and that toughened glass is required if the lean-to is over a household entrance. A lean-to beside a back door or a path is exactly where that applies, so price the toughened or polycarbonate option before you compare.

Planning permission and building regulations (England)

The Planning Portal says whether a lean-to needs planning permission depends on what it is used for: it could be treated as an extension or a conservatory, among other things, and either can be permitted development (no application needed) within limits and conditions. Greenhouse Stores reads a greenhouse attached to the house as an extension. The Planning Portal's limits for single-storey rear extensions in England include:

• projecting no more than 3m beyond the original rear wall (4m for a detached house);
• no more than 4m high, and eaves no higher than 3m within 2m of a boundary;
• extensions and other buildings covering no more than half the land around the original house.

Conservation areas, National Parks and other designated land have tighter rules; the Planning Portal's lean-to answer says listed buildings need listed building consent for significant changes. The Planning Portal also says conservatories are normally exempt from building regulations if they are at ground level, under 30 square metres, single storey, separated from the house by external-quality walls, doors or windows, have an independent heating system with separate temperature and on/off controls, and their glazing and any fixed electrical installations comply with building regulations. Any new structural opening between the lean-to and the house still needs building regulations approval, even if the structure itself is exempt. The Planning Portal notes that Welsh policy may differ, and Greenhouse Stores says Scotland and Northern Ireland set their own limits too.

None of the picks here comes near the 4m height limit, and none measures more than about 2.6m in any direction, but check with your council if you are near a boundary, on designated land or building against a listed house.

Mini lean-tos for patios and balconies

Below 2ft deep, lean-tos are shelving units with a cover. The Ida 900 is a rigid, glazed one with a sliding door and roof vent. A polytunnel (see our polytunnel vs greenhouse comparison) is the other way to get covered space cheaply if you have open ground rather than a wall.

How we chose

We have not tested these greenhouses in person. Picks are chosen from the specifications on UK retailer pages checked in October 2026, maker information and owner discussion, to cover different wall heights, depths, glazing and budgets. None of these picks has an affiliate link.

Which should you choose?

• House wall, plenty of height, want the most options: Elite Kensington 6x8.
• Want a twin-wall polycarbonate roof: Vitavia Ida 5200 8x6.
• Narrow side return or path: Vitavia Ida 3300 8x4 (glass) or Palram Hybrid 4x8 (polycarbonate, base included).
• Low gutter, bungalow or a timber look: Forest Wallscape 4x8.
• Patio or tiny yard: Vitavia Ida 900 4x2.

Related: Does a greenhouse need a base? What to put a greenhouse on in the UK

Questions people ask

Which direction should a lean-to greenhouse face?

South or west. Hartley Botanic recommends a south-facing wall away from tall trees, and Greenhouse Stores says south and west walls usually give the strongest growing light, east suits morning sun and north needs careful choice of crops. A south or west lean-to gets very hot in summer, so add an automatic vent opener.

Do you need planning permission for a lean-to greenhouse?

In England, often not, if it stays within permitted development limits. The Planning Portal says it depends on use, and a lean-to may be treated as an extension or conservatory, which can be permitted development within limits: for a rear extension, no more than 3m deep (4m on a detached house), 4m high, and eaves no higher than 3m within 2m of a boundary. Conservation areas and listed buildings have stricter rules.

How tall a wall do I need for a lean-to greenhouse?

Taller than the greenhouse ridge plus its base, with room left for flashing. Full-size lean-tos in this guide range from about 2.06m (Forest Wallscape) to 2.4m (Elite Kensington) to the ridge, and bases can add 6–13cm. Measure to the lowest gutter, sill or vent.

Can a lean-to greenhouse cause damp in the house wall?

It can if it is badly sealed. Greenhouse Stores advises flashing the top joint with lead or proprietary flashing rather than silicone alone, sealing every hole drilled into a cavity wall and keeping the lean-to gutter clear of the damp-proof course.

Does a lean-to greenhouse need a base?

Yes, a level and square one. Some come with a steel base (Palram Hybrid), others offer it as an extra that also raises the house (Elite, Vitavia), and the Forest Wallscape has no floor and sits on a base you prepare.

Sources

1. Elite Kensington 6 x 8 ft Lean To Greenhouse, Gardensite
2. Vitavia Ida 5200 8 x 6 ft Lean To Greenhouse, Gardensite
3. Vitavia Ida 3300 8 x 4 ft Lean To Green Greenhouse, Gardensite
4. Vitavia Ida 900 4 x 2 ft Lean To Green Greenhouse, Gardensite
5. Palram Canopia Lean To Silver Hybrid 4 x 8 ft Grow House, Gardensite
6. Forest 4 x 8 ft Wallscape Lean-To Greenhouse, Gardensite
7. Lean To Greenhouses, Greenhouse Stores
8. Lean-to and house-attached greenhouses: planning in the UK, Greenhouse Stores
9. What direction should a lean-to greenhouse face?, Hartley Botanic
10. What can you grow in a lean-to greenhouse?, Hartley Botanic
11. Extensions: planning permission, Planning Portal
12. What permission is required to build a lean-to at the side of my house?, Planning Portal
13. Conservatories: building regulations, Planning Portal
14. Can a lean to greenhouse damage house bricks/cause problems?, DIYnot forum