The short answer
A greenhouse base in the UK typically costs roughly £150–£800, depending on the type and the size of the greenhouse. The lower-priced option is usually paving slabs on compacted hardcore, often around £100–£200 for a 6x8, while a concrete pad is the most durable and commonly runs £200–£400 for a small base and more for larger footprints. A DIY concrete base can range from about £150 for a small 6x4 up to £800 for a 12x10. A good base is level, solid and free-draining, because a greenhouse frame needs even support — an uneven base strains the frame and cracks the glazing.
The base is easy to underestimate, but it is what keeps the frame square and the glazing intact. Here are the typical types and what each tends to cost.
Typical UK base costs
- Paving slabs (6x8)~£100–£200
- Concrete pad (small)~£200–£400
- DIY concrete (range)~£150–£800
- Key requirementlevel, solid, free-draining
- Most durableconcrete pad
The main base types
- Paving slabs on hardcore: often the lower-priced route — slabs bedded on compacted MOT Type 1, typically around £100–£200 for a 6x8. Good for most standard models.
- Concrete pad: the most durable base, commonly £200–£400 for a small greenhouse and more for larger ones, lasting decades with no maintenance.
- Perimeter / plinth base: a manufacturer's steel or timber base frame that lifts the greenhouse and helps anchor it; priced as an add-on.
- Self-build: doing the base yourself can range from about £150 for a small slab base to £800 for a larger concrete one, plus your time and curing days.
| Base type | Typical figure | Notes |
|---|---|---|
| Paving slabs (6x8) | ~£100–£200 | lower-priced, widely used |
| Concrete pad (small) | ~£200–£400 | most durable |
| DIY concrete (size range) | ~£150–£800 | 6x4 up to 12x10 |
| Perimeter / plinth base | add-on | manufacturer base frame |
Indicative UK figures for guidance. Sources: Checkatrade and greenhouse base guides.
Why a level, solid base matters
A greenhouse frame is only as true as the base beneath it. If the base is uneven, the frame is forced out of square, doors and vents stop closing properly, and the glazing comes under stress and can crack. A base should be level, solid and free-draining, with the footprint matched to the model. Concrete gives the longest-lasting, most stable result, while a well-laid slab base is a sound lower-priced choice for most standard greenhouses. Spending a little more on the base usually works out lower in cost over time than dealing with a frame that never sat square.
Want the base sorted as part of the quote?
We'll match you with a vetted greenhouse supplier or installer who sets out the right base for your model and site, and prices it clearly alongside the structure.
Frequently asked questions
How much does a greenhouse base cost?
Typically around £150–£800 depending on type and size. Paving slabs on hardcore are often the lower-priced option (around £100–£200 for a 6x8), while a concrete pad is the most durable, commonly £200–£400 for a small base and more for larger footprints.
What is the best base for a greenhouse?
A level, solid, free-draining base is essential. Paving slabs on compacted hardcore suit most standard models and are lower-priced, while a concrete pad is the most durable and stable, lasting decades with no maintenance.
Do I need a special base for a greenhouse?
You need a level, solid base matched to the greenhouse footprint. An uneven base forces the frame out of square and stresses the glazing, so it is worth getting right whether you use slabs, concrete or a manufacturer's base frame.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific garden and choices. They are guidance, not a quotation.