Ask five greenhouse suppliers for a multi span greenhouse cost and you will get five different numbers per square meter. The gap is rarely about margin. It comes from design decisions that are buried inside the quotation: how many spans, how much steel is in the frame, which film or panel is specified, and how much climate equipment is included.
This guide breaks down the real cost drivers of a commercial multi span greenhouse in 2026 so you can read a quotation critically and compare offers on equal terms.
What a Multi Span Greenhouse Includes
A multi span greenhouse is a gutter-connected structure: two or more bays share columns and gutters to form one continuous growing volume. A complete system normally covers five layers of scope:
- Structure - hot-dip galvanized steel frame, columns, trusses, gutters, arches
- Covering - polyethylene film, polycarbonate panels or glass
- Ventilation - roof vents and/or side vents, manual or motorized
- Climate systems - shading, cooling pads, exhaust fans, circulation fans, heating, fogging
- Growing systems - irrigation, benches, gutters, drainage
Only the first two are usually quoted at a comparable price point. The rest is where totals separate.
The Five Cost Drivers That Matter Most
1. Span width and bay layout
Span width is the single biggest lever. Narrow spans (6 m) require more columns, gutters and foundations per square meter than wide spans (8 m, 10 m, 12 m). Wide spans reduce steel per square meter, but they demand heavier trusses and better ventilation design. For most vegetable operations, 8 m to 10 m spans give the best balance of steel cost, airflow and internal working space.
2. Steel weight and galvanizing
Two quotations can look identical on a drawing and differ by 20-30 percent in steel weight. Always ask for the steel section sizes and the galvanizing standard. A hot-dip galvanized frame with adequate zinc coating is the difference between a 15-year structure and a 25-year one. Thin, pre-galvanized tube is cheaper up front and far more expensive over the life of the house.
3. Covering material
Covering choice changes both the initial cost and the operating cost:
- Polyethylene film - lowest capital cost, fastest to install, good light transmission; needs re-covering every 3-5 years depending on UV additive and climate
- Polycarbonate panels - higher capital cost, better insulation, 10+ year service life, preferred for cold winters and seedling production
- Glass - highest capital cost, longest life, best light transmission, used for high-value and research facilities
Film houses usually win on cost per square meter; polycarbonate and glass win on energy and longevity. The correct answer depends on your crop cycle, not on the price list.
4. Climate control scope
This is where budgets move the most. Basic ventilation and shading might add a small fraction to the structure cost. A full package - cooling pads, exhaust fans, internal shading, circulation fans, heating and automatic control - can add more than the structure itself in hot or cold climates. Specify the systems your crop actually needs; oversized climate packages are one of the most common sources of overspend.
5. Installation, foundations and freight
Greenhouse pricing is frequently quoted EXW or FOB, which excludes the costs that decide the final project number: container volume, sea freight, port charges, foundation work, erection labor and supervision. Wide-span structures ship efficiently because fewer columns means fewer parts - but long gutters and trusses can limit container loading. Always convert every offer to a delivered and installed cost per square meter before comparing.
Indicative Budget Structure
The table below shows how a typical commercial multi span film greenhouse budget is distributed. Use it as a share-of-total check, not as a price list - actual figures depend on climate, crop, automation level and site conditions.
| Cost element | Typical share of total project cost | Main variables |
|---|
| Steel structure and covering | 35-50% | Span width, steel weight, film or panel grade |
| Ventilation and climate systems | 15-30% | Climate zone, automation level, cooling or heating needs |
| Irrigation and growing systems | 8-15% | Drip or sprinkler, benches, gutters, drainage |
| Freight and logistics | 5-15% | Container loading, destination port, distance |
| Foundation and installation | 10-20% | Local labor rates, soil conditions, site access |
Where Growers Commonly Overspend
- Buying climate equipment before defining the crop plan. A tomato house and a seedling nursery need different systems at the same footprint.
- Choosing the cheapest film. Re-covering twice in five years costs more than buying a 4-year or 5-year UV film once.
- Ignoring gutter height. Low gutters save steel and lose air volume, which pushes cooling costs up in summer and limits crop height.
- Comparing FOB prices. Two FOB offers are meaningless until both are converted to delivered and installed cost.
- Skipping the foundation design. Under-designed anchor and foundation details cause the failures that no warranty covers.
How to Compare Quotations Properly
- Request a per-square-meter price for the same span, bay length and gutter height.
- Require steel section sizes, galvanizing standard and film specification in writing.
- Separate structure, covering, climate equipment and growing systems into line items.
- Ask for container loading plans and the exact scope excluded from installation.
- Check references in a comparable climate, not just a comparable crop.
Frequently Asked Questions
Is a wider span always cheaper?
Per square meter of floor area, wider spans reduce column and gutter count, so steel cost usually falls. But wide spans need heavier trusses and more careful ventilation design. Beyond about 12 m the savings flatten out.
Film or polycarbonate for a first commercial project?
For mild climates and seasonal vegetable production, film is normally the right first investment. For cold winters, high-value seedlings or year-round production, polycarbonate's insulation and lifespan usually justify the higher capital cost.
How long should the structure last?
A properly hot-dip galvanized steel frame with adequate coating typically serves 20-25 years. The covering is a wear item: film 3-5 years, polycarbonate 10-15 years, glass 20+ years.
What size project justifies a multi span design?
From roughly 1,000 m2 upward, the shared-gutter design starts to pay back on steel savings and improved climate uniformity. Smaller plots are usually better served by single or tunnel houses.
Next Step
Send us your crop, site location, target area and climate conditions, and we will return a design recommendation with a transparent per-square-meter cost breakdown for your project. You can review our greenhouse product range or contact our engineering team directly with your requirements.
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