A greenhouse is a purchase you live with for ten years or more, so a little time spent on the choice pays off. Answer these questions in order and the list of candidates gets short fast.
1. What do you want to grow?
- Tomatoes, cucumbers and chillies in summer: almost any greenhouse works. You need room for growbags or big pots and good ventilation.
- Seedlings in spring: you need staging and some way to keep frost out on cold nights in March and April.
- Tender plants over winter: you need insulation and a heater. Twinwall polycarbonate, or a glass house lined with bubble insulation, holds heat better than single glazing alone.
2. How big?
Nearly everyone who buys a greenhouse wishes it were bigger after the first season. A 6x8 ft greenhouse (about 4.5 m²) is the most common size in the UK and fits two growbags on one side and staging on the other. Our greenhouse size guide works out what fits for your plans. Browse by size under small greenhouses, 6x8 greenhouses and large greenhouses.
3. Glass or polycarbonate?
Glass lets in the most light, looks good and lasts for decades. Horticultural glass is cheap but breaks into sharp shards. Toughened glass costs more and breaks into small blunt pieces, the better choice near children and ball games. Polycarbonate is light and hard to break, and twinwall panels insulate better than single glass. The full comparison is in polycarbonate or glass.
4. Where will it stand?
Pick the sunniest spot you have, out of the shade of trees and buildings and sheltered from strong wind. Keep it close to a tap and, if you want a heater, within reach of an outdoor socket. With little space, a lean-to greenhouse on a sunny wall is worth a look.
5. What goes underneath it?
Most aluminium greenhouses need a base. Some makers include a steel base, many sell it as an extra, and none of them stand well on bare soil without anchoring. Plan the base before you order. The greenhouse base guide covers slabs, concrete and timber.
6. Enough vents?
A greenhouse with one roof vent overheats on a sunny day in May. Look for at least one roof vent per 6 ft of length, plus a louvre or a door you can leave open. An automatic vent opener does the work while you are out. More in the ventilation guide.
7. Do you need planning permission?
In England most garden greenhouses count as permitted development, as long as they stay within height and position limits. Big greenhouses near a boundary, listed buildings and conservation areas are where it gets tricky. Our planning permission guide lists the rules from the Planning Portal.
8. What does it really cost?
Compare the price per m² and what is in the box, not the headline price alone. A cheap greenhouse without a base, gutters or vent opener can end up costing more than a dearer one with all three. Our score includes price per m² for that reason. You can filter by budget under under £300, under £600 and premium.
Where to start
Use the greenhouse finder to narrow the list by size, glazing and budget, or open all greenhouses and sort by score. Before you buy, put two or three side by side on the comparison pages.
