The question I hear most is “how much per ping (3.3 m²)?” Without drawings and a business plan, I cannot conjure an answer out of thin air, so rather than rushing a quotation I ask three questions: what will you grow? who will buy it? how many years to payback? Until those are answered, floor area and unit price are the wrong conversation, because a greenhouse is not a machine you buy; it is a business you open.
Cost Thinking vs. Investment Thinking
Cost thinking compares which greenhouse is cheaper; investment thinking compares which one pays itself back. A cheap greenhouse that cannot survive a typhoon, or becomes too hot to grow in over summer, is wasted money at any price; an expensive greenhouse specified beyond what the crop needs never recovers the extra outlay either. The specification should be “just right”, and that presupposes knowing what the greenhouse is meant to earn.
The Numerator: What a Year Earns
The ROI numerator is annual net profit. Annual revenue = yield × unit price × marketable percentage, and each of those three should be a conservative figure:
- Yield: the figure your own growing skill can deliver, not the catalogue or demonstration-farm figure; discount the first year further, since every new facility has a ramp-up period.
- Price: the year-round average, not the post-typhoon spike reported in the news; under a contract-farming agreement, use the contract price.
- Marketable percentage: growing a crop is not the same as selling it. Deduct for grade-outs, sorting to buyer specification, and how much volume your sales channel can absorb.
The Denominator: The Investment Is More than the Structure
Many owners start calculating payback from the structural quotation alone, then watch costs keep surfacing once construction starts. A complete denominator includes at least:
- Planning and design fees: without a business plan and construction drawings, everything else is guesswork.
- Site preparation, drainage and foundations: on low-lying sites this line item is often far larger than expected.
- Structure and covering: steel and aluminium framing, plus polyethylene film, polycarbonate (PC) sheet or glass.
- M&E and climate control — fans, pads, shading, irrigation, control panels, plus utility applications and external lines.
- Miscellaneous and contingency: freight, statutory fees and permit agents, then 10–15% of the total held in reserve.
Run It Once — Hypothetical Numbers, Real Method
Say the total investment is NT$6 million, annual revenue NT$3 million and operating cost NT$2 million: NT$1 million net a year, a six-year payback. Now press three further questions. The covering is typically replaced every two to five years, so more money goes out before payback. One typhoon loss inside those six years pushes the date out. And what would the same capital earn elsewhere? My rule of thumb is blunt: if the payback period exceeds half the service life of the main facility, the project goes back for a rethink. Reduce the scale, change the crop, or hold off on building.
After the Math, Only Three Outcomes
- It works: the payback period is reasonable and the risk is bearable. Tender from the drawings and put the money where it counts.
- It is marginal: reduce the scale or build in phases, letting the phase-one harvest fund phase two; or switch to a higher-value crop and run the numbers again.
- It does not work: hold off on building. Lease an existing facility or run trial crops under a contract-management arrangement, build up the growing skill and the sales channel, and revisit the numbers in a year or two. The numerator will be far more realistic by then.
“Hold off on building” is professional advice too. We build greenhouses for a living, so by rights we should want everyone to build. But a greenhouse that never pays back is good for no one. I would much rather your business makes money; that is what a long-term working relationship is built on.
This is exactly why Hwa-Nan puts planning before design: we work through the business plan and the ROI with you, confirm that the build is worth it and at what scale, and only then move to drawings and quotations. The clearer the numbers, the sounder the greenhouse.
From site assessment and design to construction and aftercare, HWA-NAN provides end-to-end greenhouse services. Tell us about your site and goals — the initial consultation is free.