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Lean-To Greenhouse

The 20 Best Lean-To Greenhouses In The UK

League Table By: Tony Dimmick

Last Checked: 1st Jul 2021

Andrew Wilcox

Head Judge: Andrew Wilcox

Channel 4’s Head Judge & Founder of Shed of the Year Andrew Wilcox has worked to help design an impartial judging system for WhatShed. The judging system uses many different parameters to help give a large degree of impartiality to the way we select products for each of the league tables we do. You can read more about the system here.

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If you’re serious about your gardening then a lean-to greenhouse is an essential purchase. The vagaries of the British weather can play havoc with your pots and beds, but a greenhouse means that the less hardy vegetables or flowers that you grow will be given protection from the elements when they need it most. Greenhouses come in a wide range of styles and varieties of course, but lean to greenhouses can be especially useful because they typically take up less space in your garden, can often provide better value for money, and benefit from the residual heat coming from the wall that supports them. If you want to find the model that’s perfect for your garden, then help is at hand with our WhatShed guide to the top 20 lean to greenhouses for sale in the UK today. 

At WhatShed we review garden buildings in all shapes and sizes, from large metal workshops to small summer houses and everything in between. That’s why we’ve been able to use our knowledge and experience to create this league table of the very best lean-to greenhouses. Our research led us to look at over 90% of the lean to greenhouses currently for sale in the UK from the top 10 retailers that you can rely on. This means that you can be sure that each lean to greenhouse featured in our top 20 really will make a positive difference to your garden.

Do you still have questions on what greenhouse will best suit your needs? Check out our helpful buying guide to give you some ideas! View our Greenhouses guide

8'x4' Palram Hybrid Silver Lean To Wall Walk In Greenhouse (2.4x1.22m)

The top three of our WhatShed 20 best lean to greenhouses is dominated by those which are approximately four foot by eight foot, and yet by combining high quality materials, a long warranty period, and great value for money, this is the deserving winner of the prestigious number one spot. It has a width of 1.35m, a depth of 2.49m, and a peak height at the top of its pent roof of 2.09m but whilst these are all very impressive in their own right, this is a garden building that has much more to offer. It comes with an integrated base and two roof vents, and the wooden frame can be taken in either a treated or natural finish. That’s just one of the many options available to the customer, another being the option to upgrade the standard horticultural glazing to tougher safety glass that meets the exacting BS6206 standard, or even polycarbonate glazing for the toughest finish of them all. With such a low starting price, we can imagine many people taking advantage of one of these options. What we liked most of all is that it comes complete with a 12 year warranty, and this, combined with its comparatively low price, makes it our number one choice for people who are looking for a large and accommodating lean to greenhouse.

6'x12' Palram Rion White Sun Room Walk In Wall Greenhouse (1.8x3.6m)

Lean to greenhouses in any size bring a wide range of benefits, not least that they can help your plants achieve their true potential whilst making the most of the space available. Larger examples of the genre, however, bring a whole range of other benefits too, and in effect this Rion sun room provides two functions in one. On one hand it can be used as a greenhouse that holds a large amount of potted or bedding plants. Alternatively it can be used as a conservatory, and an extra room to enjoy on your property. This is much larger than the previous sun room in our top twenty list which makes it much more versatile, and with a very reasonable price tag attached as well it deserves to be at number two in our league table. We found that the large dimensions made the white resin frame look even more imposing and attractive, and the 4mm polycarbonate glazing is as tough as any that we’ve seen on the lean to greenhouses that we review. It would take a real concerted effort to break this glazing, which gives added security and peace of mind too. One thing that we particularly liked, and which was surprising in a garden building of this size, is that it takes no tools to construct it; everything simply clicks into place and once assembled its very strong and reliable, as the 7 year warranty shows. If you want a lean to greenhouse that can also be used as a conservatory, this is the building for you. See WhatShed full review

6'x12' Palram Rion White Sun Room Walk In Wall Greenhouse (1.8x3.6m)

There were lots of factors that we took into consideration when deciding what deserved to be in our top 20 best lean to greenhouses available online in the UK today, but one thing that repeatedly gained a high position is a spacious and well constructed greenhouse that’s available for much less than others of a similar size. That’s the overriding reason why this larger model in the Halls Silverline range makes it into our top three, and yet it has a lot more to recommend it as well as the highly useful base area of 3.85 X 1.91m, and a ridge height of 2.34m. One feature that differentiated it from many of its competitors is that it has not one but two roof vents, and this means that your much loved plants will be protected from the potentially damaging effects of overheating. Further ventilation is supplied by the sliding single door, which has a width of 0.57m. Whilst we would have liked this to be a little wider, it’s still possible to manoeuvre a chair through it, which is particularly useful as we can imagine this being used as a place to sit in and look out at your garden as well as being used as a great value lean to greenhouse. See WhatShed full review

6'x10' Palram Rion White Sun Room Walk In Wall Greenhouse (1.8x3m)

This features the curved eaves design that we find very attractive on lean to greenhouses, and this is one of the largest examples that we’ve seen in this style and it also offers excellent value for money. Added value is provided by the inclusion of a 12 year frame guarantee, which is the equal longest of any guarantee on this type of greenhouse and helps it achieve its position just outside of our top three. The long warranty period shows the confidence that the manufacturer has in the material that they’ve used, and we have to say that it’s a confidence we share. The aluminium is thicker than a lot that we see, as is the 3mm thick horticultural glazing. What we also liked about the glazing is that it simply clicks into the frame and is then held firmly in place, so the building is very easy to construct if you have a friend along to help. There’s even a built in gutter, and the door can be positioned at either end so that it suits the unique aspects of your garden and home. For a lean to greenhouse that offers a base size of 3.23 X 1.91m, and an unusually generous height of 2.47m, you’d probably expect to pay much more, not less, then six hundred pounds. See WhatShed full review

8'x4' Palram Hybrid Silver Lean To Wall Walk In Greenhouse (2.4x1.22m)

Whilst the Halls range of lean to greenhouses may lack the sophisticated design of some that we review, they always offer good value for money and solid reliability. This is the best example of that we’ve found, meaning that a medium to large greenhouse can be bought for well under three hundred pounds. It is this great value for money from a manufacturer you can trust that sees this particular garden building deservedly break into the top five. The natural aluminium frame is a cost effective and yet dependable substrate, as is the horticultural glass glazing although you won’t want to put this to the test in an area where children are playing. There’s one vent in the roof, and the side door slides open to allow access. What sets this aside from its competitors at this price however is its width of 2.55m, its depth of 1.29m, and its peak height at the top of the pent roof of 2.21m. Quite simply this is the best value for money lean to greenhouse that we’ve reviewed, and so it has to be worth considering by people for whom price is the major factor, although you may want to spend a little more money to add the galvanised steel base kit or even an an auto-opener for the vent. See WhatShed full review

Adley 8' x 4' Lean-To Greenhouse

A large timber lean to greenhouse such as this is not only a great place to grow your plants, maximising the benefits from the sun that a south facing positioning provides as well as picking up the extra heat coming through the wall of your home, it also makes your property as a whole look more attractive and this can bring substantial benefits if you come to sell the house. There are three substrates on show here, the Western Red Cedar frame, tough plastic guttering, and tough safety glass that meets the BS6206 standard, and we feel that they all blend together very harmoniously. This is certainly a greenhouse that you’ll be proud to have in your garden, although we would advise painting or staining the timber to give it added protection against the fading effects of the sun. There’s lots of room inside, thanks to the base area of 2.99 X 1.94m, and the height of 2.28m. There are three vents, which is more than we are used to seeing even on greenhouses of this size, two on the top and one on the face, and another feature that helped propel this up the WhatShed list of the very best lean to greenhouses is the key operated lock. It means that not only can you keep plants inside, and there’s full length staging to help with that, you can also store tools securely. See WhatShed full review

6'x8' Palram Rion White Lean to Greenhouse (1.8x2.4m)

We now move from a garden building that costs over three thousand pounds to one that costs less than less than four hundred, which shows the great variety that makes up our list of the top 20 lean to greenhouses on sale today. The one thing that unites all of our buildings however is quality, whether of design, components or both. That’s certainly the case with this Halls Silverline greenhouse, and we really liked the aesthetic appeal of its compact design and gently curving eaves. We were surprised by how much fits inside this greenhouse, and that’s helped by an above average height of 2.34m, as well as a depth of 1.91m which is lot more than we often find on a lean greenhouse with a width of 2.34m. There’s a sliding door and one roof vent, and it was good to find that the diagonal bracing meant that the lightweight aluminium frame feels solid and reliable. Whilst this doesn’t include many of the value adding features we often find on other greenhouses we review, such as an extended warranty or an integral base, this achieves its very high position thanks to the exceptional value for money that we feel it offers customers who want a decent sized lean to for their garden but who are working to the confines of a limited budget. See WhatShed full review

Adley 4' x 8' Lean-To Wooden Greenhouse

This is by far the largest lean to greenhouse that we’ve reviewed, but it’s also by far the most expensive which is the only reason that it hasn’t reached the very top positions in our list. Just how big it is is shown by its width of 6.36m and its depth of 2.01m, and the ridge height of 2.91m is also the tallest that we’ve seen so if you need a large greenhouse area for your plants and aren’t put off by a price in excess of three thousand pounds, then this could be your personal number one choice. So impressive are the dimensions of this lean to greenhouse that we can imagine it being used for light commercial, as well as keen amateur, purposes. You’ll certainly fit a lot of plants inside, and once they’re they’ll benefit not only from the sun which beams through the tough safety glass which is sealed with superior quality silicone, but from excellent weather protection. Thermowood has been used for the frame, which means that a heat treatment provides the long lasting protection of tanalisation without the use of any harsh chemicals. Further protection is offered by a 20mm thick PVC damp barrier. We also liked the fact that there are four vents on the roof, and that they’re all fully ventilated. This is a grand and impressive greenhouse in every sense, including the price. See WhatShed full review

Adley 8' x 4' Lean-To Greenhouse

This medium sized lean to greenhouse makes it into the upper half of our top 20 not only for its good looks, but also because it offers good value for a wooden greenhouse that comes complete with a 10 year guarantee. It’s worth pointing out that this guarantee is dependent upon the timbers being treated with an appropriate wood preserver before the installation is carried out, but at this size that needn’t be a time consuming or expensive process. The base dimensions of this greenhouse are 2.50 X 1.30m, and the height at the top of the pent roof is 2.10m. The roof itself features an integrated vent, which we’re used to seeing on the lean to greenhouses that we review of course, and it was good to see that it could be propped open to give day long ventilation on hotter days. Styrene is used for the glazing, but whilst this isn’t as elegant as safety glass, for example, it’s difficult to tell the difference from a distance and it is both tough and cost effective. It’s one reason why this lean to greenhouse can be yours for less than £700, a price that’s very reasonable when compared to similar sized buildings with shiplap timber frames, which is itself one reason that we rate it so highly. See WhatShed full review

Adley 4' x 8' Lean-To Wooden Greenhouse

We begin the top 10 selection of our lean to greenhouses currently on sale in the UK with perhaps the most attractive and elegant building on our list, and indeed its only the relatively high price point for what is a mid sized greenhouse that stops it being placed even higher, although it’s worth noting that free installation is included within the price. The wooden frame and pent roof follow a very traditional design, and yet the materials used are of a very high quality. In fact, the timber used is known as thermowood which means that it has had a unique and patented heat treatment prior to manufacture to give it excellent resilience against rain and rot. As well as the tough frame itself there’s also staging that runs along the full 2.54m width of the building. This is an ideal place to site your pot plants, and it’s protected by a centre support which makes the building as a whole very solid and sturdy. Another feature that we liked is that the single door, which has a height of 1.98m so you won’t need to bend down when going in or out, has a key operated mortice lock. This gives excellent security if you plan on keeping tools or gardening equipment inside, and is another reason why this is one of the best, if not cheapest, lean to greenhouses that we’ve reviewed. See WhatShed full review

Waltons 8 x 4 Evesham Lean-to Pent Wooden Greenhouse

This is the second lean to greenhouse from the Vitavia Ida range to make our top 20 list, but the reason for this model’s loftier position is that it offers a lot more room to grow plants in and yet still offers very good value for money. In fact, this looks very different to the Ida 900 that we mentioned earlier, mainly thanks to the dark green anodised aluminium frame and the sliding double doors that make it very easy to manoeuvre plants in and out. There’s still the very useful opening vent on top of the pent roof, so you want have to worry about dangerous heat build up on the sunnier summer days. We were pleased to see the use of anodised aluminium for the frame, as it’s much more water resistant than standard aluminium. This means that you won’t have to worry about unsightly corrosion, a fact that’s confirmed by the inclusion of a 10 year manufacturer’s guarantee. The base size of 2.59 X 1.31m, with a height of 2.20m, makes this an ideal accompaniment for a small garden so if you want a mid sized lean to greenhouse that lasts and lasts this is a garden building that could bring you exactly what you’re looking for at a relatively affordable price. See WhatShed full review

6'x6' Palram Rion White Lean to Greenhouse (1.8x1.8m)

The Sun Room range from Rion, a renowned manufacturer of greenhouses and garden buildings, offer much more than just a lean to greenhouse, in that they can be utilised as an extension to the house itself. This is the entry level model, with a base area of 1.98 X 1.96m, but that means that it offers comparatively good value for money and whilst you may find it a little cramped to sit and enjoy a sunny day in, there’s lots of room to grow those plants that thrive from extra heat and sunlight. The first thing that struck us when reviewing this garden building is just how smart it looks, and that’s because the white resin frame reminded us of the PVC cladding and roof lines that are found in increasing numbers across the UK today. It’s also a very tough and weather proof substrate, which is good news for the plants that you keep inside and good news for your pocket too as it comes with a 7 year structural guarantee. Polycarbonate is used for the glazing, and at 4mm it’s noticeably thicker than most polycarbonate that we see and also incredibly strong. With its combination of durability, good looks and affordability this is a worthy entrant in our list of the top 20 lean to greenhouses. See WhatShed full review

65 x 24 Halls Wall Garden 26 Greenhouse (1.94 x 0.69m)

This is another six foot by two foot lean to greenhouse, which is a very popular size for this product as it allows for a good number of plants to be stored whilst not taking up an excessive amount of room in the garden. In short, we feel that this is the ideal size for a first greenhouse, and this makes an ideal first purchase primarily because of the exceptional value for money it offers. It doesn’t come with the extended warranty that many of its competitors do, but its solid construction and high calibre components mean that we feel it should last much longer than its one year guarantee suggests. The frame itself is made of aluminium which gives the greenhouse an attractive silver finish. Horticultural glazing is used for the building, so while this is tough enough for everyday use you may wish to upgrade to safety glass. On hot days a central vent in the roof can be opened to give your plants much needed ventilation, and access is provided quickly and easily via a front sliding door. If the dimensions of 1.92 X 0.67m, with a height of 1.81m, meet your requirements then at this low price its a lean to greenhouse that you can’t go wrong with. See WhatShed full review

Halls 6Ft X 2Ft Supreme Curved Lean To Wall Garden

We always like to see elegant curved eaves used on a compact lean to greenhouse such as this, as after all a great greenhouse should be pleasing in form as well as function. It’s another of the greenhouses that are perfect for the small scale hobby gardener, but it comes with a matching price that makes it affordable to almost anyone. The peak height is 2.28m, but the base size is almost square, measuring 1.93 X 1.95m, so you’ll be surprised at just how much you can fit inside, especially with an abundance of integrated shelves. The frame itself is made of aluminium, so brings a very contemporary look to the garden, but its thickness of 3mm is so tough and reliable that the manufacturer has been able to give a 12 year guarantee on the frame. This is in excess of the vast majority of the warranty periods that we see, and is one of the factors that propelled this lean to greenhouse into our top 20 list. We were also pleased to see that toughened safety glass had been used, especially at this price, as it’s even tougher than the standard horticultural glass that we often find on budget priced greenhouses of all sizes. The glazing simply clips into place, so it’s very easy to install, which is another tick in its list of benefits. See WhatShed full review

8'2 x 4'4 (2.49x1.32m) Windsor 84 Wooden Lean-To Greenhouse

A wooden lean to greenhouse has both advantages and disadvantages when compared to its steel or aluminium framed cousins. On the downside they can require regular re-treatments with preservative to keep the threat of rot at bay, which can bring demands in both time and money, but on the plus side they have a timeless look that many people find very attractive. We can certainly imagine this mid sized lean to adding to the beauty of any garden, and we found it very well constructed too. One example of its strength and durability is that it features a heavy duty frame which, at 45 X 27mm, is thicker than many others that we see on the wooden greenhouses we review. Tongue and groove timbers have been used, which are naturally good at repelling water, and we were pleased to see that an initial basecoat had been applied and also that they came with a 10 year anti-rot guarantee as long as the treatment schedule is adhered to. The glazing itself is made of styrene, which although not as elegant as many other forms of glazing is very tough and virtually shatter proof. These are just some of the reasons that make this a worthy addition to our lean to greenhouse league table. See WhatShed full review

Waltons 8 x 4 Evesham Lean-to Pent Wooden Greenhouse

We now take a significant step up both in the size of the greenhouse and in cost, and both of them have been taken into account when considering its eventual position in this list of the UK’s best lean to greenhouses. It’s also the first wooden greenhouse that we’ve included, and the western red cedar frame gives a classic and attractive look. If you have a traditional garden, whether used for flowers or vegetables, then this is sure to fit in well and it will catch the eye of your neighbours and passers by. The width of the building is an impressive 2.40m, with a depth of 1.93m, and the pent roof with a built in vent peaks at 2.26m. One feature that we particularly liked is that there is a strong gutter and downpipe attached to the building which collects rainwater that can then be used on the plants. In this way, it’s a greenhouse in more ways than one. We were also impressed by the 10 year anti-rot guarantee which is testimony to the natural resilience and rot resistance of the oil rich western red cedar as a substrate. On the downside, however, this costs substantially more than many of its competitors which is why it isn’t placed higher on our list of the top 20 lean to greenhouses.

6'5 x 2'4 Halls Green Wall Garden 26 Greenhouse (1.94 x 0.69m)

We were struck by the elegance of this aluminium framed lean to greenhouse and in large that’s thanks to the racing green colour scheme applied to the metal. It’s a little thing, but it makes a big difference when it comes to aesthetic appeal and helps to raise it above many of its competitors at this size. The curved eaves are also a nice decorative touch, and we have to say that this is one garden building that looks much more expensive than it actually is. The base dimensions of this greenhouse are 1.93 X 0.71m, and it reaches a height of 2.08m, so it’s a good choice for gardens and patio areas where space is at a premium. An integrated base rail is included, although a base isn’t so you’ll have to be careful what you place on the lower level unless you purchase the optional base kit or add a base yourself from OSB or exterior grade plywood for example. Horticultural glass is used for the glazing, and a smoothly sliding door provides easy access to the interior. Whilst this is very much at the smaller end of the buildings on this list, it takes its place in our top 20 lean to greenhouses for offering a sophisticated and attractive design at a very affordable price. See WhatShed full review

Garden Grow Three-Tier Wooden Cold Frame

This shares the same 4′ X 2′ dimensions as the previous lean to greenhouse in our top 20 league table, and yet it offers much more besides and for a fraction of the price. We were surprised at just how versatile this is for such a small garden building, and one reason for that is that it incorporates two integral shelves. These are ideal for placing potted flowers on, and the lower level can be used for storage of items such as soil, fertiliser or a watering can which won’t be affected by the proximity of ground moisture. Whatever you want to store in this garden station you won’t have any problem in taking in or out, and that’s because the glazing opens up completely to give full access to the interior. The double hinged doors and hinged roof can also be left in the open position if required to give natural ventilation to your plants. The shelves are made of galvanised steel, and so won’t be affected by moisture from plant pots, and the frame itself is made from aluminium. This means that this should be a long lasting building, even though it doesn’t come with an extended warranty. Overall, we feel this represents great value for a versatile and compact lean to greenhouse. See WhatShed full review

Garden Grow Compact Greenhouse 4x2ft

This is the first traditional lean to greenhouses in our league table, and it offers a significant step up from the previous entrant in both size and price. Even so this is very much at the smaller end of the market, with a width of 1.20m and a depth of 0.60m, and it reaches a peak height of 1.83m. Once again then this is ideal for the hobbyist gardener, and we can easily imagine it being used on a balcony or small patio area. There is one opening vent in the roof, and the frame used is an anodised steel that’s been pre-treated to protect it from corrosion. This is a good touch for a greenhouse of this size, and means that the manufacturer has been able to supply a ten year warranty for the frame. We were very glad to see this, as it gives added peace of mind to the customer, but on the other hand it has to be said that this is significantly more expensive than some other lean to greenhouses of a similar size. If you want a small greenhouse, however, and don’t mind paying upward of two hundred pounds for it then we feel that this should be on your short list. See WhatShed full review

Gardman Raised Wooden Cold Frame

This differs markedly from the other garden buildings in our list, but we feel that it still deserves to be considered as a lean to greenhouse on the basis that it can easily be positioned against a wall and that it will benefit from the added weather protection that this brings. It’s the smallest and most lightweight building in our league table too, but that brings the added benefit of portability. Putting this wooden cold frame together is simplicity itself, and once up it can simply be placed next to the protection of a house or garden wall. The dimensions of 0.90 x 0.50m can’t match up to the greenhouses you’ll find below, but this makes it ideal for a person who has a small garden yet wants to protect their plants against the threat posed by cold autumn and winter nights. Being raised from the ground on four timber legs it also means that it’s ideal for people who have difficulty in bending down and the polycarbonate glazing that surrounds the plants, and which is protected by a roof that can be locked in an open position, creates an attractive frame for flowers especially. We wanted to include a product that was ideal for those with small gardens and small budgets, and that’s why this deserves to be at the beginning of our list of the top 20 lean to greenhouses. See WhatShed full review

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  • John Owen said...

    Thank you for the survey , I have been looking for and trying to buy a 6 X 8 or 10 ft lean to aluminium frame only .I am limited by height ,so I am looking to purchase a frame only which I will cut to size and then fit the glazing .
    In nearly all cases when asked for frame only I am quoted a cost greater than the total package .
    Can you direct me to a frame only supplier ?
    Many thanks , John


    • Richard said...

      Hi John, we have not come across a frame only supplier. You could try contacting Vitavia at the following link https://www.vitavia.co.uk/ You might have some luck with them as they are a UK maker of greenhouses. Failing that eBay is a good option for a frame only option.


  • Ibo said...

    Very helpful article.
    This is ideal. Very happy with this overview to understand my options on shapes, sizes & prices. I was wondering how to search for all of this and am delighted to find it in one convenient place.
    Now to check the piggy-bank – and talk to my landlord! :o)


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