Greenhouses of 25 m2 and Larger
A greenhouse of twenty five square metres or more is the largest format we stock. At this scale the structure stops being a seasonal shelter and becomes a permanent part of how the garden works. There is room for beds down both sides, a central path a barrow can pass along, and a working area that does not have to be cleared before the next job starts.
The floor plan allows genuine zoning. Tender crops can sit at one end and hardy stock at the other, each vented differently, because the volume of air is large enough that one end does not immediately affect the other. Smaller houses rarely allow this, since opening a single vent changes conditions throughout.
If you are weighing this against something more modest, the large greenhouse range covers everything from ten square metres upward, and the size guide sets the bands side by side.
Groundworks Come First
At this size the base matters more than the frame. A structure of twenty five square metres carries considerable weight in glass alone, and it presents a large surface to the wind. The ground needs to be level, drained and firm before any frame arrives, and the base needs to be square to within a few millimetres or the glazing will not seat.
Most owners at this scale lay a concrete perimeter or a full slab. Whichever you choose, the frame still has to be fixed down. Our greenhouse bases and anchor kits cover soil, gravel, paving and concrete, and fitting one during assembly is far easier than retrofitting it afterwards.
Fitting Out the Interior
A house this size needs its interior planned rather than filled as you go. Staging along one wall and permanent beds along the other is the most common layout, with the path down the middle wide enough for a wheelbarrow. Head height under the ridge is usually enough for trained fruit and vines.
- Permanent beds hold soil temperature better than containers and suit long season crops.
- Staging keeps propagation at working height and frees the floor beneath for storage.
- A hard path prevents the centre of the house turning to mud in winter.
Our greenhouse staging and bench range is sized for standard widths, so a run can be planned before the frame goes up rather than measured afterwards.
Climate at Scale
A large volume of air is slower to heat and slower to overheat, which works in your favour in spring and against you in midwinter. Heating output should be matched to the cubic volume of the house rather than its floor area, a distinction that catches out most first time buyers at this size.
Ventilation matters just as much. Roof vents and louvres shift a fixed volume of air, so a house of this footprint usually needs several rather than one. The vents and louvres range and the temperature control section between them cover what a house this size actually requires.
Before deciding what to add, it is worth knowing what the space does on its own. A maximum and minimum thermometer left in place for a fortnight will tell you more than any specification sheet.
Is This Size Right for You
Twenty five square metres and above suits growers aiming at year round supply, gardeners with an established collection that has outgrown its space, and anyone who wants the greenhouse to be somewhere to spend time rather than only somewhere to work. It is a substantial commitment in cost, groundworks and maintenance, and it repays that with capacity nothing smaller can match.
If the growing matters more than the entertaining, an orangery may suit better, since it is built to hold warmth for people as much as for plants.
