From Floor Area to a Profit-and-Loss You Can Take to the Bank
Greenhouse cost and profit planning turns a structure into a business case: what it costs to put up, what it costs to run for a year, what it sells, and whether the money left over pays back the build in a reasonable time. Most people stall at the first number, the sticker price of the frame, and never get to the one that decides everything: gross profit per square foot per year. That is the figure the calculator above hands back once you enter your own area, capital, cycles, and operating lines.
Two houses the same size can land on opposite sides of viable. A 2,880 ft² poly high tunnel growing lettuce for a farmers market clears its operating cost and pays for itself in a season or two. The same footprint in heated glass, growing a low-value crop for wholesale, can lose money every winter on the fuel bill alone. The structure isn’t the variable that matters most. The crop, the market, and the energy line are.
How Much Does It Cost to Build a Greenhouse?
Greenhouse construction cost is usually quoted per square foot of floor, and it swings mostly on the covering and whether you count the systems inside. A single-layer poly hoop house or high tunnel runs about $2 to $5 per ft² for the bare structure. A gutter-connected double-poly range lands near $8 to $15 per ft², and glass or polycarbonate climbs to $20 to $35 or more once you add heating, benches, and controls. In whole numbers, a 30 ft × 96 ft high tunnel (2,880 ft²) is roughly $6,000 to $15,000 depending on how much heat, irrigation, and bench you build in. A commercial gutter-connected acre (about 43,560 ft²) starts north of $1 million. If you’re growing on a seasonal high tunnel, check whether your USDA NRCS field office will cost-share it through the EQIP high tunnel practice, which can cover a meaningful slice of the frame.
| Structure type | Cost per ft² | Typical use |
|---|---|---|
| Hoop house / single-poly high tunnel | $2–$5 | Season extension, unheated or lightly heated |
| Gutter-connected double-poly | $8–$15 | Year-round commercial vegetables and greens |
| Polycarbonate | $15–$25 | Durable hobby through mid-scale commercial |
| Glass (Venlo) | $20–$35+ | High-tech, fully climate-controlled production |
These are frame-plus-glazing figures with basic systems. Automated screens, supplemental lighting, CO₂ injection, and full environmental controls add up fast, and on the high-tech end can rival the cost of the structure itself. A hobby lean-to or freestanding kit at 6 ft × 8 ft up to 8 ft × 12 ft usually runs a few hundred to a few thousand dollars all in. Different scale, same math once you enter it above.
Is a Greenhouse Profitable?
A greenhouse can be quite profitable, but it depends on three things far more than the building: the value of the crop, the market channel, and the energy cost of holding temperature. High-value crops like lettuce, culinary herbs, vine tomatoes, and bedding-plant transplants, sold direct or on a tight wholesale contract, routinely clear operating cost and pay back a poly house in one to three years. A bulk, low-margin crop in a heated glass house in a cold climate often can’t cover the fuel bill. The number to compare across plans is gross profit per square foot per year, not total revenue, because it normalizes for size. A well-run intensive vegetable house often targets roughly $3 to $10 per ft² of annual gross profit; propagation and high-value specialty crops can beat that, and a poorly matched crop-and-market can sit at or below zero. Land-grant enterprise budgets, like those from Penn State Extension, are the honest reference here, since they carry the labor and energy lines most back-of-envelope plans leave out.
Three Numbers Decide It: Capital, Operating Cost, and Revenue
The model behind the calculator is deliberately plain. Capital is what you spend once to build. Operating cost is what you spend every year to run. Revenue is what the crop sells for. Everything else (payback, return on capital, margin) falls out of those three.
Annual gross profit = Revenue − Operating cost
Payback (years) = Startup cost ÷ Annual gross profit
Startup cost is floor area times structure cost per square foot, plus the one-off items (heater, benches, irrigation, permits). Revenue in yield mode is usable area times units per square foot per cycle times price times cycles per year.
Notice revenue keys off usable area, not the full footprint. Aisles, the headhouse, and wall clearance take 25 to 40 % of the floor before a plant goes on a bench, which is exactly what the Greenhouse Capacity Planner sizes. Feed this calculator the usable fraction from that one and your revenue line stops being optimistic fiction.
A 2,880 ft² Lettuce High Tunnel: The Full Money Picture
Say you put up a 30 ft × 96 ft high tunnel at $4/ft² and add $8,000 of heater, benches, and drip. Usable area is 70 % of the floor. You grow butterhead lettuce at 2 heads/ft² of bench per turn, sell at $2/head, and get 8 turns a year.
| Line | Calculation | Result |
|---|---|---|
| Startup cost | 2,880 × $4 + $8,000 | $19,520 |
| Usable area | 2,880 × 0.70 | 2,016 ft² |
| Annual heads | 2,016 × 2 × 8 | 32,256 |
| Revenue | 32,256 × $2 | $64,512 |
| Operating cost | energy $6k + labor $22k + plants/media $6k + water $2k + other $3k | $39,000 |
| Gross profit | $64,512 − $39,000 | $25,512 |
| Payback | $19,520 ÷ $25,512 | 0.8 yr |
That is the optimistic, everything-sells version, and it still hides risk: it assumes you move all 32,256 heads at $2. Drop the sell-through to 80 % or the price to $1.50 and the picture tightens fast. Run a low case before you believe the good one. Labor is the line that quietly decides most of these operations, since intensive vegetable production is far more hands than a field crop of the same value.
Energy Is the Line That Makes or Breaks a Cold-Climate House
In a heated house north of the 40th parallel, energy can run 15 to 30 % of total operating cost, and in a bad winter it can eclipse labor. Before you commit to a heated glass structure, size the heating load with the Greenhouse Heating & Cooling Load Estimator and put a real fuel number into the operating line here. Double poly instead of single cuts heat loss by roughly 30 to 40 %. A thermal or shade screen trims it further. Siting the house behind a windbreak cuts the wind infiltration that drives cold-night loss. These aren’t rounding errors. They move the payback by seasons.
The inputs you buy also belong in the operating line at their real cost. The Fertilizer Cost per Nutrient Unit Calculator prices the nutrients you run through the benches, and the Seed & Fertilizer Rate Calculator sizes the seed and transplant order behind your plants-and-media number.
Budget Mistakes That Turn a Good Plan Into a Loss
- Reading gross profit as take-home. Gross profit ignores the wear on the structure. A poly cover lasts 4 to 6 years, so a slice of every year’s profit is really replacement money. The net-profit line here subtracts straight-line depreciation so you see that.
- Leaving labor out or lowballing it. Transplanting, harvesting, and packing a lettuce house is real hours. Value your own time at a wage you’d pay someone else, or the operation only looks profitable because you worked for free.
- Sizing revenue off the full footprint. Multiply price by usable bench area, not the whole floor. Skipping the aisle deduction inflates revenue by a third before you start.
- Believing one price and 100 % sell-through. Markets soften, crops cull, and shrink is real. Model the year you sell 80 % at a lower average price, then decide if the capital still makes sense.
Connecting the Money to the Rest of the Build
Cost and profit is the last question in a greenhouse plan, not the first. Size the space and plant count with the Greenhouse Capacity Planner, size the climate system with the Greenhouse Heating & Cooling Load Estimator, and bring the whole picture back here to see whether the numbers clear. For the wider operation, the Agriculture & Farming hub maps every tool to the job it settles.
Cost and profit outputs are planning estimates built from the numbers you enter. They don’t model financing, taxes, insurance, or salvage value, and construction quotes, crop prices, and energy costs move constantly. Use the result to compare scenarios and pressure-test a plan, then confirm with real contractor bids, current market prices, and your local extension farm-business specialist before committing capital.
Last updated: July 7, 2026