By clicking a retailer link you consent to third party cookies that track your onward journey. If you make a purchase, Which? will receive an affiliate commission which supports our mission to be the UK's consumer champion .
A greenhouse is a major investment for your garden and one that’s not easy to move or replace once installed, so it's important to pick the right one for your needs. Our expert guide tells you everything you need to know. Arched Greenhouse
Whether you're shopping for a small greenhouse to protect young plants or a larger alternative to work on fruit and veg, we can lend a helping hand. On this page, we've rounded up details on optimal materials and sizes, features to look out for, greenhouse accessories and heaters.
Keep scrolling for an overview of popular greenhouse types, plus our top tips on how to build a greenhouse for yourself.
Breathe new life into your outside spaces. Sign up for our Gardening newsletter, it's free monthly
Pros: Lets in light from all sides, lots of choice, often roomy enough to work in
Cons: Can lose heat as all sides are exposed, you will have to find a way to get power to it
Freestanding greenhouses are often made from wood, aluminium or PVC. They are usually square or rectangular with an apex roof.
Most gardeners will opt for a 6 x 8ft (1.8 x 2.4m) or 8 x 10ft (2.4 x 3m) model. Think about freedom of movement and what you plan to grow when determining the ideal size – you might need double doors to move plants in and out, for example.
Freestanding greenhouses allow light in from all four sides, although this means they're more exposed to the elements compared to other greenhouse types. You can install bubble insulation if needed. As these greenhouses can be quite large, you might also want to run electricity to the space so you can see in low light.
When deciding where to position your freestanding greenhouse, consider which parts of your garden get plenty of sunshine. You also need to think about the impact of strong gusts of wind and whether the building is well-protected.
If you need additional space for your gardening equipment, check in with our guide on how to buy the best outdoor storage .
Pay £36.75 for the first year and get the garden you want for less
Pros: Wind resistant, maximises unused space, can be particularly energy efficient
Cons: Not as much space to plant a variety of crops, fewer sides for light to enter
If you're shopping for a greenhouse that isn't exposed to the elements from every angle, consider a lean-to greenhouse. These join to an existing structure, such as a house or garage (shown above).
These greenhouses are a popular choice among gardeners working with limited space in their backyard, or those that want a greenhouse closer to their home. Having your greenhouse within a shorter distance means you don't need to run water and electricity across the full length of your garden.
Lean-to greenhouses are often made from wood, although this needs to be maintained over the years, making aluminum a tempting alternative. The initial purchase costs are similar to a freestanding model, but a lean-to takes up less space and you only need access around three sides. It is also cheaper and easier to keep warm.
Pros: Space-saving, cheaper than a full-sized greenhouse, most can be stowed away
Cons: Can be difficult to tend to plants if you have limited mobility, limited growing space
A mini greenhouse is like a glazed cupboard with shelves that sits on a patio or under a window, using a house wall or garage as protection – perfect if space is limited. It will protect trays or pots of young plants from late frosts in spring, and encourage borderline crops such as peppers to ripen.
Ideally, a mini greenhouse should face east or west. South-facing ones overheat in spring or summer unless shaded, and north-facing ones suit only shade-loving plants.
Mini greenhouses are generally easy to set up and maintain, making them well-suited to both newbies and experienced gardeners. Some feature built-in grow lights, and many models can be dismantled and repositioned (or stored away) when needed.
We've used greenhouses to trial a selection of tomato varieties – see the full results with our guide on how to grow tomatoes .
Most greenhouse frames are made of aluminium. Wooden greenhouses are also available, though, and many gardeners find them more attractive to look at, despite the fact they need more maintenance compared to metal frames.
Pros: Budget-friendly, durable, plain silver is maintenance-free, light and easy to assemble
Cons: Fastenings needed to attach shading material, tricky to extend, insulation can be poor, usually need to add your own base
Aluminium is the most common material for greenhouses, which means you’ll be spoilt for choice. These models are available in a variety of shapes and sizes, so you'll have some options that suit your budget.
Generally speaking, aluminium greenhouses are considered low maintenance as they're able to withstand harsh weather. Aluminium won't warp or crack over time, and the material is rust-resistant. A lightweight metal construction also ensures the greenhouse is easy to move or dismantle.
Pros: Can stain to a specific colour, easy to attach shading material, better insulation
Cons: Can be expensive, usually need to add your own base (keeping the wooden frame off the damp ground), vulnerable to rust, needs regular maintenance
Wooden greenhouses are less common and typically cost more than their aluminium counterparts. Picking the right type of wood will help avoid a greenhouse that’s vulnerable to rot. Softwoods, such as deal (pine), are vulnerable to rot, even if the timber has been treated.
Wood is a natural insulator, so it should retain heat fairly well once winter rolls around. You can add additional insulation panels to your wooden greenhouse if needed.
Naturally durable timber – usually western red cedar – can be left to age to a silver-brown. For looks, a western red cedar greenhouse is hard to beat. Look for manufacturers that offer a guarantee against rot.
For gardeners working with a limited budget, be aware that you'll usually need to add your own base to a wooden greenhouse.
If you think you'd benefit from adding a shed to your garden, consult our in-depth guide on how to buy a shed .
Glass is the main glazing material used in greenhouses, hence the alternative name ‘glasshouse’. Horticultural glass is inexpensive and easily replaced, but if you're concerned about breakages or safety, you can opt for a plastic greenhouse.
Plastic greenhouses have twin-walled polycarbonate sheets. Polycarbonate greenhouses let in sufficient light for plant growth initially but, over the years, they can become cloudy and age poorly. Toughened glass is a better option, particularly if the greenhouse is on show.
Toughened or safety glass is stronger than horticultural glass and, if it does break, the resulting pieces are not so sharp. Choosing this option adds about £200 to the cost of a small greenhouse.
Another option is a self-adhesive safety film – this is a transparent film applied to horticultural glass. If the glass is subsequently broken, the film holds the fragments together. However, as the film does not reduce breakages, it could end up more expensive than choosing toughened glass from the start.
To find out which products will leave your plants looking good through summer, explore our controlled-release fertilisers reviews .
If you're shopping for a greenhouse on a limited budget, the most affordable option will be a smaller, aluminium model. You can expect to spend around £200, although prices can rise depending on the quality of the materials used.
Greenhouses on sale for less than £200 are often classed as a 'mini greenhouse' or a 'cold frame greenhouse' – both can easily be moved to a spot in your garden that's well-suited for growing specific plants. Models that allow varying levels of ventilation are popular, as are cold frames that can be set up on gravel or paved areas.
Larger, wooden structures and greenhouses with ready-made shelving and additional accessories can cost anywhere between £1,000 and £4,000.
Discover the best pop-up plastic greenhouses
Both generalist retailers and dedicated garden shops offer a wide range of greenhouses. To make sure you're buying a greenhouse that's safe to use, only shop with trusted sellers online or in-store.
Ideally, you'd get to see the greenhouse in-store before buying. If this isn’t an option, find out as much information about it as possible before parting with your money.
Popular online retailers that sell greenhouses include:
See which retailers are rated highly with our guide on the best and worst shops .
The size of your greenhouse will be limited to what you can fit in your garden. For most of us, it will be fairly modest, especially if you live in a city. Larger structures typically cost more, so even if size isn’t a factor, budget might be.
Your best bet is to opt for the biggest greenhouse you can. Width is an important dimension because this will determine the benches and aisles. Below, we've listed some of the most common greenhouse sizes:
Most people opt for a 6 x 8ft (1.8 x 2.4m) or 8 x 10ft (2.4 x 3m) freestanding greenhouse. This is wide enough for a central path, with shelving on one side to hold a propagator and potted plants, and a greenhouse border on the other side, so tall cropping plants, such as cordon tomatoes and cucumbers, can be planted directly into the soil.
12ft wide (around 3.6m) is a semi-professional width, and anything above this is typical for commercial use.
When settling on a greenhouse size, make sure you can get in and out of the door easily and that you feel comfortable once inside. Note that low greenhouses can feel claustrophobic.
If space is limited, you might want to opt for a mini greenhouse that sits under a window or against the wall.
Fancy upgrading your gardening equipment? Explore our gardening tool reviews .
In practice, there are probably only one or two suitable places in your garden, and this will limit the size of greenhouse you opt for – which is why most people end up with a small one. Here are some top tips to help you pick the perfect position for your greenhouse:
For a tradesperson you can trust, visit Which? Trusted Traders and find a professional near you. You can also use our Trusted Trader search tool below.
You'll need an electric fan heater rated at least 2kW to guarantee keeping a standard 6 x 8ft greenhouse frost-free in most parts of the UK.
If you opt for a gas or paraffin heater, it'll need to be about 20% more powerful – this is to compensate for heat lost via the vents left open to allow poisonous gases and water vapour out and oxygen in.
Lining the greenhouse glass with bubble insulation will also help to retain the heat and keep your structure snug in the depths of winter.
Compare gas and electricity prices now using Which? Switch , our independent energy comparison website. check wording of this link
Make more of your garden – get our free Gardening newsletter for top tips from our experts
Get the power of Which? in your pocket by downloading our app, giving you on-the-go access to our reviews
Get the power of Which? in your pocket by downloading our app, giving you on-the-go access to our reviews
Chat to a live agent or send us a message
Farmers Friend Greenhouse Chat to a live agent or send us a message