Greenhouse Sizes
We know about greenhouses and we knowthe sizes that are top of your list. For the smaller garden the smallest width available is 6ft 8 inches (2026mm). The length is modular starting with two panels which is just 5ft 4 inches (1622mm) long. The most popular length for this width is 3 panels which is a little shy of 8 foot (2362mm).
The most popular size greenhouse we sell is exactly 8ft wide (2438mm) and is available in different lengths to suit your needs. A popular length for this is 4 panels which measures 10ft 5 inches (3187mm). This model is suitable for the average size garden.
The largest width model is rather grander at 10ft 7 (3218mm ). We have designed our range to enable you to increase the length in 750mm (2ft 6 inch) panels so our greenhouses stretch as far as your imagination or your neighbour’s fence.
Not only does the floor area of our greenhouses compare favourably to the competition but the overall height gives a high volume of air. Lots of head room and high eaves ensure your shoulders will not feel constricted and make for a comfortable environment. For instance our 8ft by 10ft greenhouse is almost 10ft high. Plenty of air is good for plants and people.
How to Choose the Right Greenhouse Size
The right size is rarely just about the footprint. A greenhouse that feels adequate in the garden plan often feels crowded once staging, a potting area, and a path are factored in. As a rule, buy one panel longer than your initial estimate: the extra 2ft 6 inches (750mm) costs relatively little but makes a significant difference to how the space works day to day. For gardens with limited width, a lean-to model uses wall space instead of garden space, often delivering more usable growing area than a freestanding structure of the same footprint. If you are undecided between two sizes, the configurator lets you compare both side by side before committing.
Greenhouse Sizes FAQs
The smallest practical size is 6ft 8in wide by 8ft long (2026mm x 2362mm). Below this, headroom becomes restrictive and there is limited space for staging on both sides. If your garden is genuinely tight, a lean-to or three quarter lean-to against a wall will give you more usable internal volume than a small freestanding structure.
The 8ft wide (2438mm) model at 4 panels long (3187mm, just over 10ft) is the most popular combination. It suits an average garden, fits two runs of staging comfortably with a central path, and provides enough headroom at almost 10ft high for tall crops like tomatoes and climbing cucumbers.
Greater height means more air volume, which buffers temperature swings and gives headroom for tall plants and the gardener working alongside them. Cultivar greenhouses are notably taller than many competitors at the same stated footprint. An 8ft by 10ft model reaches close to 10ft at the ridge, which accommodates full-height tomato plants on staging without restriction.
Yes. All structures use a modular panel system in 750mm (2ft 6in) increments, so additional length can be added to the gable end at a later stage. It is worth planning your base slightly longer than the initial structure if extension is likely, as this avoids groundwork later. See the full base preparation guide for details.
Staging runs along both long sides of the structure. A central path of around 600mm is the practical minimum for comfortable movement. Subtract the path from the internal width and divide the remainder across both sides for a rough staging depth per side. For a more accurate layout, the accessories page shows the staging dimensions available for each width.
Yes. Planning permission rules for outbuildings consider total ground coverage relative to the property. A greenhouse should not cover more than half the total garden area, and structures within 2 metres of a boundary must not exceed 2.5 metres in height. Larger models are more likely to approach these thresholds. If you are close to a boundary or have a smaller plot, check with your local planning authority before ordering.
Common questions about choosing the right greenhouse size for your garden and how dimensions affect growing.