Project route
New Greenhouse Build vs Retrofit of an Existing House
Retrofit is usually the faster and cheaper route to better climate control, but only within the limits the existing frame allows. Gutter height, structural loading and ventilation area cannot be bought back later — they decide whether retrofit is an upgrade or a ceiling.
Direct answer
When is a greenhouse retrofit not worth it?
When gutter height, structural loading or ventilation area limit the climate you can achieve. Those are frame properties: spending on screens, cooling or controls inside a house that cannot support them buys equipment, not results. Commission a structural and climate survey first.
| Dimension | New build | Retrofit / upgrade |
|---|---|---|
| CAPEX | USD 0.5M–3.5M / ha depending on technology | USD 80K–600K / ha depending on scope |
| Timeline | 12–30 months including permits and site works | 3–9 months, often between crop cycles |
| Production downtime | None on existing area | One cycle or partial-block phasing |
| Climate control achievable | Anything the budget supports | Bounded by gutter height, loading and vent area |
| Typical scope | Structure, covering, climate, irrigation, automation, site works | Screens, fertigation, sensors, controls, cooling, recladding |
| Permitting | Full planning, water and grid approvals | Usually limited or none |
| Financing view | Project finance or long-tenor lending on a new asset | Equipment leasing or shorter-tenor facilities |
| Risk | Cost and schedule overrun on site works | Discovering the frame cannot carry the intended package |
Cost delta at a glance
- •A screens-plus-fertigation-control retrofit typically costs USD 80K–250K per hectare and is the highest-return upgrade in most heating-driven climates.
- •Adding active cooling or recirculation to a low house often costs 60–80% of new-build value while delivering a fraction of the control — a structural survey should precede any quote.
- •New build carries 15–35% of budget in site works, water and grid that retrofit largely avoids.
Planning-grade ranges for budgeting only. Actual pricing depends on site, specification, climate and supplier scope.
Choose New build when
- Existing frame too low, too weak or too poorly ventilated for the target crop
- Expansion of area rather than improvement of control
- Projects needing bankable, long-life assets for financing
Choose Retrofit / upgrade when
- Sound frame with adequate gutter height and ventilation area
- Energy, water or labour cost is the problem rather than capacity
- Cash-flow-constrained operators needing improvement within one season
Frequently asked questions
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