Greenhouses in the UK are sold in feet: 6x4, 6x8, 8x10. The real size often differs a little from the name, so always check the actual measurements on the product page.
Feet to square metres
Multiply length by width in feet, then by 0.0929 to get square metres.
| Size | Floor area |
|---|---|
| 6x4 ft | about 2.2 m² |
| 6x8 ft | about 4.5 m² |
| 6x10 ft | about 5.6 m² |
| 8x8 ft | about 5.9 m² |
| 8x10 ft | about 7.4 m² |
| 14x20 ft polytunnel | about 26 m² |
What fits where?
6x4 ft
Room for one growbag along the back, or staging on one side. Fine for a few tomato plants and some seed trays. Feels cramped quickly.
6x8 ft
The most popular size in the UK. One side for two growbags of tomatoes or cucumbers, the other side for staging and seed trays, and a path down the middle. This is the size most beginners should start with.
6x10 ft
The same layout as a 6x8 with more length, so you fit a third growbag or more staging.
8x8 and 8x10 ft
The extra width gives you beds or staging on both sides with a comfortable path. Room for tomatoes, cucumbers, peppers and a propagation corner, or a winter collection of tender plants.
Polytunnels
For serious growing on a budget, a polytunnel gives you far more space per pound. A 14x20 ft First Tunnels polytunnel covers about 26 m².
How to work out your size
- Count your crops. Plan the growbags or big pots you want along the sides.
- Add staging for spring seedlings, about as much as you would fill with seed trays in April.
- Leave a path you can kneel and work in.
- Then add some extra. Almost everyone fills a greenhouse in the first season.
Check the space you have
- Measure the base size, not the nominal size, and leave room around the outside to clean and reach the gutters.
- Check the height against the planning permission rules if the greenhouse will stand close to a boundary.
- Plan the base for the real footprint.
Browse by size under small greenhouses, 6x8 greenhouses and large greenhouses, or use the greenhouse finder.
