Greenhouse Roof Shapes UK: Apex, Lean-To, Orangery, Dwarf Wall & Combi Compared by Installers
Which greenhouse roof shape works best for a UK garden? Five shapes cover almost every domestic installation we do: the apex (gable) for the widest brand and size choice, the lean-to for narrow gardens against a wall, the orangery with its raised lantern for cooler summers and a stronger architectural look, the dwarf-wall apex for serious heat retention on a brick base, and the combi greenhouse-shed for split storage and growing in a single footprint. This guide compares all five with installer notes, real prices, and the shapes we deliberately do not stock — and why.
We have fitted greenhouses across the UK since 2009. After more than 150,000 customer orders and tens of thousands of installations, the roof shape decisions below are the ones that come up most often on site visits. The recommendations are based on what we actually deliver, build, and revisit a year later, not on a manufacturer brochure.
Key Takeaways
- Apex (gable) is the UK default. Widest size range (4x6 to 16x20), every major brand, easiest to find replacement parts, two-thirds of installs we fit.
- Lean-to is the space hack — saves around 50% floor footprint by using a wall as one side. Best against a south or west-facing brick wall.
- Orangery lantern roof runs 2-3°C cooler than a standard apex on summer days because the raised lantern vents hot air upward at the ridge.
- Dwarf-wall apex stores heat in the brick base. Overnight low temperatures hold 4-5°C warmer than an all-glass equivalent.
- Combi greenhouse-sheds save you a separate shed: half growing space, half lockable storage, single footprint. Most popular in gardens under 8m wide.
- Mini lean-tos and tiered minis are the entry-level lean-to/apex equivalents for balconies, patios, and walls under 1.8m wide.
- We deliberately do not stock A-frame, gothic arch, geodesic dome or barn-roof greenhouses. The honest reasons are at the bottom of this guide.
Installer's Note
I have been fitting greenhouses across the UK since 2009. Roof shape is the question I get asked least often before purchase and the one customers regret most often afterwards. People focus on width and length, then realise three years in that the gable would have been better than the orangery for their growing budget, or that the lean-to ate sunlight they did not know they needed. The five shapes below are the only ones that show up regularly in our UK install diary — everything else (A-frame, gothic arch, dome) is either DIY-build territory or a US-market shape that does not work in our climate or planning rules. Pick by what you grow and where you put it, not by what looks Instagram-friendly.
The five greenhouse roof shapes UK gardeners actually buy
Across our install records, almost every domestic greenhouse we deliver falls into one of five roof shapes. Each shape solves a different problem. Usable height, footprint efficiency, heat behaviour, architectural fit, or split-use with storage. The right choice depends on what you grow, where you put it, and how exposed your garden is.
1. Apex (gable) roof, the UK default
The apex roof is a symmetrical pitched roof that meets at a central ridge — the classic triangular silhouette. It is by some distance the most common roof shape on UK domestic greenhouses, and the one we install most often. Every mainstream brand we stock builds an apex range: Vitavia, Elite, Halls, Palram Canopia, Swallow, Janssens, Robinsons. Sizes run from 4x6 up to 16x20 and beyond.
Two things make the apex the default. First, the symmetric pitch sheds rain and the occasional UK snow load evenly, so structural failure is rare. Second, the headroom is genuinely usable at the ridge: typically 2.0-2.3m centrally on a 6ft-8ft wide model, which makes tall crops like indeterminate tomatoes, cucumbers up a string, and aubergines straightforward. The wider the greenhouse, the higher the ridge, so an 8x10 apex gives you more vertical growing space than a 6x8 of the same brand.
Apex is also the cheapest shape to maintain. Glass and polycarbonate replacement panels are off-the-shelf for every major brand — clips, glazing bars and bar capping are stocked widely. If you are buying your first greenhouse and not sure yet how you will use it, this is the safe choice.
Best for: most UK gardens with 2m+ space on all four sides
Pick apex if you want choice of brand, easy access to spare parts, and the cheapest route into a serious greenhouse. Browse our full range of greenhouses for sale filtered by size, brand, or glazing, the majority are apex.
2. Curved-eaves apex: the modern apex variation
A curved-eaves apex is a standard gable roof with the eaves (where the wall meets the roof) softened into a continuous curve rather than a sharp 90-degree corner. The Vitavia Orion is the model we sell most of in this category — the 3800 and 5000 widths are popular at the £600-£800 price point.
The curve does three useful things. It adds 5-8cm of internal width at shoulder height, which sounds small but matters when you are reaching across staging. It softens the visual mass of the greenhouse, the building reads as more architectural and less utilitarian, which helps in front gardens or near patios. And the curve sheds wind slightly better than a sharp eaves edge, useful in exposed sites where eddies build up against vertical aluminium faces.
The cost premium over a standard apex of the same size is typically £50-£120. Glazing panels are still flat. The curve is in the aluminium extrusion, not the glass — so spare parts remain easy.
Best for: front gardens, patio installs, exposed plots
Pick a curved-eaves apex if the greenhouse will be visible from the house and you want a softer line. The premium is small, the structure is still apex underneath, and spare parts are interchangeable with the standard range.
3. Lean-to (mono-pitch) roof: the space hack
A lean-to greenhouse uses a single sloping roof pitched away from an existing wall: typically a house, garage, or boundary brick wall. The wall acts as one of the four sides, which removes around 50% of the floor footprint versus a freestanding apex of the same width. We fit a lot of these in narrow side returns and against south or west-facing walls where space is the constraint.
The wall does more than save space. A brick wall absorbs heat during the day and releases it overnight, which keeps internal temperatures 2-4°C warmer in spring and autumn than an equivalent freestanding apex. South-facing walls are the strongest performers; west-facing is fine; north-facing wastes the whole benefit. East-facing works in summer but gives nothing in winter.
The trade-off is height and width choice. Lean-tos are usually 4-7ft wide and have a low front eaves (1.5-1.8m), so tall climbing crops at the front of the growing space lose headroom. The back wall is the full ridge height, so taller crops go there. Brands we install in this category: Vitavia IDA, Elite Easygrow, Janssens Arcadia Lean-To, Palram Canopia San Remo Veranda.
Best for: narrow side returns, walled gardens, south or west walls
Browse our full range of lean-to greenhouses if you have a wall to use. Read our lean-to greenhouse buying guide before measuring — wall height and aspect matter more than width.
4. Orangery (lantern) roof: the cooler-running architectural choice
An orangery greenhouse uses a flat or shallow-pitched hipped roof with a raised central glazed lantern that runs along the ridge. The lantern is the defining feature: a clerestory box of glass sitting above the main roof line, with vents at the top that pull hot air up and out by convection. It is the shape used historically on Georgian and Edwardian orangeries, and it is now the premium-end choice across Vitavia (Hera 4500, Hera 9000) and Janssens (Kathedral) ranges.
The temperature performance is the real reason to buy one. In our install diary, orangery lantern greenhouses run 2-3°C cooler on still summer days than a closed apex of the same volume, the lantern acts as a chimney, dragging hot air out of the canopy zone without forced ventilation. That matters for crops that bolt above 28°C (lettuce, coriander, spinach) and for keeping tomato plants productive through July and August heat. The hipped roof also sheds wind cleanly from all four sides, which is useful on exposed plots.
The trade-off is cost and footprint. Orangeries start at roughly twice the price of an apex of the same width. The flat-roof sides have less internal headroom near the eaves than a steep gable, so dwarf bush crops (peppers, chillies, courgettes) work better than tall climbers under the eaves. Tall crops go directly under the lantern where the height returns.
Best for: hot summer growers, architectural gardens, premium budgets
Pick an orangery if summer overheating is your real constraint and budget allows. Our full range of orangery greenhouses sits between £1,500 and £21,000 depending on size and brand.
5. Dwarf-wall apex — heat retention on a brick base
A dwarf-wall greenhouse is a standard apex with the lower 60-90cm of each side built in brick rather than glass. The aluminium glazed frame sits on top of the brick course. It is the same roof shape as a standard apex: symmetrical pitched ridge, but the thermal performance is completely different because the brick walls act as a heat sink.
In real overnight readings from our customer installs, a dwarf-wall greenhouse holds 4-5°C warmer than an equivalent all-glass apex when external temperatures drop below freezing. The brick stores heat through the day and releases it through the night. That gives you a longer growing season at both ends — earlier sowing in February, later harvest in November, without running heaters. Wind resistance is also stronger because the lower brick course is rigid against eddies that would otherwise lift unsecured glass panels.
The cost is the obvious downside. You are paying for the greenhouse and the brickwork. Brick base preparation typically adds £800-£1,500 to an installation, depending on whether the bricks are new or matched to an existing wall. The shape is also fixed: you cannot easily relocate a dwarf-wall greenhouse without rebuilding the base. Brands we install on dwarf walls: Elite Thyme, Vitavia Cassandra, Janssens Mur.
Best for: serious year-round growers, exposed plots, traditional gardens
Pick dwarf-wall if you grow tender crops into winter or want the earliest spring sowing dates. Read our greenhouse foundation guide first. The brick base needs proper preparation to give you the heat-retention benefit.
6. Combi greenhouse-shed — apex roof in two halves
A combi is an apex-roof greenhouse with one half fitted out as a glazed growing space and the other half as a solid timber storage shed under the same continuous roof. The dividing wall is timber on the shed side and glass on the greenhouse side, often with an internal connecting door. The roof shape is still apex, symmetrical pitch over the full length. So rainfall and structural load behave like a standard gable.
This is the shape we recommend most often to customers with gardens under 8m wide who want growing space and lockable garden storage but cannot fit two separate buildings. A single 6x8 footprint becomes 4ft of greenhouse plus 4ft of shed, which is more useful than either alone for many households. The Swallow Kingfisher and Robin combi ranges are the UK benchmark — handcrafted thermo wood, 12-year warranty, free installation included in the price.
The split changes the heat profile. Glass-only is brighter and warmer in summer; combis hold heat better in winter on the shed-adjacent side because the timber wall acts like a smaller version of the dwarf-wall heat sink. Light intensity drops on the shed-side bench, so leafy crops and seedlings go there and tomatoes, peppers, and cucumbers go on the all-glass end.
Best for: gardens under 8m wide, owners who need lockable storage too
Pick a combi if you would otherwise need a separate shed. Our full range of potting sheds and combi greenhouses includes Swallow's thermo-wood combi range with free installation on every model.
7. Mini greenhouses: lean-to and tiered shapes for small spaces
Mini greenhouses come in two roof shapes: lean-to mini (sloping single-pitch against a wall) and tiered (a stepped front-pitched cabinet, typically with shelving inside). Both squeeze growing space into balconies, patios, narrow side returns and walled courtyards where a walk-in greenhouse cannot fit. The Access Herb House is the timber lean-to mini we sell most often; cabinet-style tiered minis are budget options under £150.
The lean-to mini works the same way as a full lean-to: wall absorbs heat, single-pitch roof sheds rain — but at 60-100cm depth and 90cm-2m height. It will hold a propagator, a shelf of seedlings, herbs, and salad leaves through most of the UK year. The tiered mini is colder (no thermal mass, light frame) and best for spring seed-starting and tomato grow-bags through summer.
Roof shape matters less at this size than in walk-in models. The volume is small enough that ventilation is the bigger problem. Both formats need a propped-open door or roof vent on warm days because internal temperatures can hit 40°C+ in midsummer with no airflow.
Best for: balconies, courtyards, patios, walled side returns
Read our best mini greenhouses UK guide for the full comparison across timber lean-to, aluminium walk-in mini, and tiered cabinet formats with sizes and prices.
Greenhouse roof shapes compared: which suits your garden?
The table below summarises the five main roof shapes side by side. Use it as a shortcut, then read the section above on whichever shape matches your garden and growing plans.
| Roof shape | Typical price (UK) | Headroom at ridge | Wind shedding | Heat retention | Best for |
|---|---|---|---|---|---|
| Apex (gable) | £540 – £1,099 | 2.0-2.3m (8ft wide) | Good | Standard | UK default, widest brand and size choice |
| Curved-eaves apex | £639 – £714 | 2.0-2.3m | Better than gable in exposed plots | Standard | Front gardens, architectural fit, exposed plots |
| Lean-to | £684 upward | 1.8-2.2m at wall, 1.5-1.8m at front | Strong (wall protects one side) | +2-4°C vs apex (wall absorbs heat) | Narrow side returns, walled gardens |
| Orangery (lantern) | £729 – £20,990 | 2.3-2.6m under lantern | Excellent (hipped) | 2-3°C cooler in summer (lantern vents) | Hot summer growers, premium gardens |
| Dwarf-wall apex | £1,319 – £6,330 + brickwork | 2.0-2.3m | Excellent (brick base) | +4-5°C overnight vs all-glass apex | Year-round growers, exposed plots |
| Combi (apex + shed) | £3,888 upward | 2.0-2.3m | Good | Better than all-glass on shed side | Gardens under 8m wide, need storage too |
Matt's Pick: the apex greenhouse to start with if you cannot decide
Matt's Pick: Elite Belmont 8x10 Apex Greenhouse
Best For: UK growers who want a serious gable greenhouse with proper headroom, toughened glazing, and a long-term build quality
Why I Recommend It: The Belmont's 8x10 footprint gives you two productive sides plus a wide central walkway, and the apex roof drives the central ridge above 2.3m so tomatoes go in on a full-length string without compromise. Elite's box-section aluminium frame is the heaviest gauge of the mid-market brands — we have customers still running 15-year-old Belmonts with no frame issues. Toughened glazing handles UK hail, kids' footballs, and ladders better than horticultural. After 16 years installing greenhouses, this is the gable I steer customers to when they ask "which one would you put in your own garden?"
Price: £1,339
Roof shapes we deliberately do not stock, and why
Several shapes appear in online buying guides and US catalogues but never on our delivery lorries. After 16 years of installs, here is the honest reason for each.
A-frame (no eaves)
An A-frame is a triangular roof that meets the ground directly with no vertical walls. They turn up in DIY plans and pop-up polythene tunnels. The problem in domestic use is headroom: anywhere you can stand upright is a narrow strip along the centre, and the sloped walls waste growing space at the perimeter. Every commercial brand has moved away from A-frame for walk-in greenhouses for this reason.
Gothic arch (curved-sides)
A gothic-arch greenhouse uses curved aluminium ribs meeting at a pointed peak, like a vertical lancet window. It is popular in North American snow zones because the steep curve sheds heavy snow loads. In the UK, snow loading is rarely the design constraint — the structural risk is wind, not snow weight, and the curved glazing panels are non-standard, expensive to replace, and not stocked by any UK retailer at sensible prices. We have never had a customer ask for one twice.
Geodesic dome
A geodesic dome is a hemispherical shell built from triangular polycarbonate panels. Aesthetically striking but practically poor for serious UK growing: internal layout wastes a third of the footprint to curved walls, planning permission is fiddly because of the unusual outline, and replacement panels are bespoke. Useful for show gardens and tropical display, not for tomatoes.
Barn (gambrel) roof
A barn or gambrel roof has two slopes per side. A shallow upper pitch meeting a steeper lower pitch. It is a North American shape used to maximise loft headroom in barns. UK suppliers do not stock it in greenhouse format because the apex already gives enough ridge height for domestic gardens, and the extra eaves complexity raises cost without adding usable growing volume.
Hexagonal / octagonal
Hexagonal and octagonal greenhouses use six- or eight-sided floor plans with a faceted pyramid roof. They are decorative focal-point pieces — Palram Canopia made the Oasis range, others made the Eden Bourton. UK availability has been patchy in recent years and we no longer stock a current model. If you want a faceted decorative greenhouse, expect a long wait time and limited spare part support.
Matt's Tip: Pick the Roof Shape Before the Brand
Most customers shop by brand first ("I want a Halls / Vitavia / Elite") and end up with a shape that does not suit their garden. Do it the other way round. Decide the shape, apex, lean-to, orangery, dwarf-wall, combi. Based on your wall aspect, garden footprint, and growing plans. Then pick a brand within that shape category. Every major brand we stock has at least three of the five shapes, so brand loyalty does not need to compromise the roof choice. After 16 years of site visits, the customers happiest with their greenhouse a year later are the ones who got the shape right first.
How to choose: a practical decision tree
The shape question has a small number of inputs. Walk through them in this order and you usually arrive at one or two candidates.
- Do you have a south, west, or east-facing brick wall with 2m+ height available? If yes, a lean-to or lean-to mini halves your footprint and warms the structure overnight. If no, skip to step 2.
- Do you need garden storage as well as growing space, in a single building? If yes, a combi greenhouse-shed is the only shape that solves this in one footprint. If no, continue.
- Is summer overheating your biggest constraint (bolting lettuce, heat-stressed tomatoes)? If yes, an orangery lantern roof is the best-performing shape we sell. If no, continue.
- Do you grow tender crops into November and start sowing in February? If yes, a dwarf-wall apex on a brick base gives you the longest season without heating costs. If no, continue.
- Default to apex. Choose curved-eaves Apex (Vitavia Orion) over standard gable if the greenhouse is visible from the house and you want a softer line. Otherwise standard apex (Vitavia Venus, Elite Belmont, Halls Cotswold, Swallow Robin) is the right answer for most gardens.
Once the shape is decided, brand choice narrows quickly. Read our greenhouse size guide next — width and length matter more than most buyers realise.
Frequently asked questions
What is the most popular greenhouse roof shape in the UK?
Apex (gable) is the most popular UK greenhouse roof shape, accounting for around two-thirds of domestic installations. Every major brand builds an apex range from 4x6 up to 16x20. It is the safest first-greenhouse choice because spare parts, glazing panels, and bar capping are stocked by every UK supplier.
Does roof shape affect greenhouse heat retention?
Yes. Roof shape changes heat retention meaningfully. Dwarf-wall apex holds 4-5°C warmer overnight than all-glass apex because the brick base stores daytime heat. Lean-to runs 2-4°C warmer than freestanding apex when fitted to a south or west wall. Orangery lantern runs 2-3°C cooler on summer days because the lantern vents hot air upward.
Which greenhouse roof shape is best for high winds in the UK?
Dwarf-wall apex and orangery lantern shed wind better than all-glass apex. The brick base of a dwarf-wall removes the lower-aluminium-panel uplift point that fails first in storms. The hipped roof of an orangery sheds wind cleanly from all four sides. On the most exposed coastal and Scottish Highlands sites, we recommend dwarf-wall over any all-glass shape.
Is a lean-to greenhouse worth it instead of a freestanding apex?
Yes: if you have a south, west, or east-facing brick wall with 2m+ height available. The lean-to uses the wall as one side, saving around 50% of the floor footprint, and the wall absorbs daytime heat to keep the greenhouse 2-4°C warmer overnight. North-facing walls cancel the benefit because the wall stays cold.
What is an orangery greenhouse?
An orangery greenhouse uses a flat or shallow-pitched hipped roof with a raised glazed lantern running along the ridge. The lantern is a clerestory box that lets hot air vent upward by convection, keeping the canopy 2-3°C cooler than a closed apex on summer days. Vitavia Hera and Janssens Kathedral are the two ranges we install most often.
Do you sell gothic arch or geodesic dome greenhouses?
No — we do not stock gothic arch, geodesic dome, A-frame, or barn-roof greenhouses. The honest reason is that UK climate and planning rules favour apex and lean-to shapes; the curved-panel shapes are expensive to maintain, hard to source spare glazing for, and rarely outperform an apex of the same internal volume. We focus on the five shapes our customers actually use successfully.
Can you put any greenhouse on a dwarf wall?
No. Only models designed for dwarf-wall fitting work properly on a brick base. Elite Thyme, Vitavia Cassandra, and Janssens Mur are built with the lower frame profile that bolts onto a 60-90cm brick course. A standard apex sat on top of an unmatched brick wall will leak at the joint and void the warranty. Order the dwarf-wall version of the model from the start.
