How to Build a Cheap Hoop House Greenhouse in Your Backyard

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A simple hoop house, a row of bent pipes covered in greenhouse plastic, is one of the cheapest ways to grow vegetables for more of the year. The free plans this page originally shared describe a structure about 11 feet wide, 15 feet long and 7.5 feet tall, built from PVC hoops and plastic sheeting for roughly $50 to $200 depending on the materials you already have or can salvage. Below is what such a build involves, what to watch out for, and what a backyard greenhouse can and cannot do for your food and the planet.

What a hoop house is and why it works

A hoop house (also called a high tunnel or polytunnel) is a walk-in tunnel of arched hoops covered with polyethylene film. Sunlight passes through the plastic and warms the soil, plants and air inside; the cover slows that heat from escaping and blocks wind. The curved shape also sheds rain and light snow.

The result is a pocket of milder weather. New Mexico State University's extension service, which publishes a detailed hoop house guide, says the inside typically runs about 4 to 6 °F warmer than outside, and a floating row cover over the beds adds a similar boost. That is enough to start crops earlier in spring, keep them going later into autumn and, in many climates, grow cold-hardy greens through winter.

The basic build: materials and steps

Low-cost plans share the same core parts:

  • Hoops: lengths of PVC pipe bent into arches. NMSU recommends sturdy 2-inch pipe for strength and says to use new pipe, because PVC that has weathered in the sun turns brittle. Thinner pipe is cheaper but flexes more.
  • Base and anchors: a wooden baseboard frame, with the hoops slipped over or fixed to stakes driven into the ground. Rebar stakes driven at an angle hold the frame down in wind.
  • Ridge and bracing: a pipe or board running along the top, plus diagonal braces, stops the arches from racking sideways.
  • Cover: greenhouse-grade polyethylene film, usually 6 mil thick and UV-treated. Ordinary builder's plastic breaks down in sunlight within a season or two; proper greenhouse film can last many years.
  • End walls and door: framed with timber, covered in film, with a door at one end and ideally a vent at the other.

The build order is simple: level the site and lay out a square base, set anchor stakes, fit the hoops, add the ridge and braces, frame the ends, then stretch the film tight on a calm, warm day and fasten it to the baseboards with wooden battens or wiggle-wire channels.

What it really costs

The $50 figure assumes free or reclaimed timber and the thinnest pipe and plastic. Buying everything new costs more. NMSU's own materials list for a larger, sturdier tunnel totalled about $1,178 at 2019 prices, around $2.50 per square foot. For a small backyard version, a realistic budget is somewhere between the two, with the greenhouse film and the pipe as the main expenses.

Spending a little more on UV-stabilised film, thicker pipe and good anchors usually saves money, because a cheap cover that shreds after one summer or a frame that folds in the first storm has to be replaced.

Site, ventilation and weather

Choose a level, well-drained spot in full sun, away from trees and buildings that cast shade. Orientation is a trade-off: an east–west run catches more winter light, while a north–south run can ventilate better in hot, windy regions, which is why the NMSU guide prefers it for the American Southwest. Check local rules too; some towns and homeowners' associations limit outbuildings.

The most common beginner mistake is overheating. On a sunny day a closed tunnel can get hot enough to damage plants even in early spring, so plan roll-up sides, a door you can prop open, or vents at both ends. Water access matters too, because rain does not reach the beds.

Wind and snow are the main threats to a PVC frame. NMSU says its 2-inch PVC design can handle winds of about 50 mph and occasional snow about 10 inches deep; beyond that, brush snow off promptly and add extra bracing. Lighter designs need more care.

What to grow, and when

A small hoop house shines with crops that like cool, sheltered conditions: lettuce, spinach, kale, chard, Asian greens, radishes, carrots and herbs. Planted in late summer or early autumn, many of these keep producing well into winter. In spring the tunnel gives tomatoes, peppers and cucumbers a head start of several weeks, and in cooler regions it can be the difference between a ripe crop and green fruit at the first frost. Rotating crops and adding compost each season keeps the soil productive.

Home-grown food: benefits and honest limits

Growing your own vegetables gives you produce picked at its best, control over how it is grown, and the satisfaction of knowing exactly where dinner came from. Freshness has a nutritional side as well. Some vitamins, vitamin C in particular, decline during storage, so leafy greens eaten soon after harvest are at their peak.

Two common claims need care. First, "food miles" are a smaller part of food's climate impact than many people assume. Our World in Data, summarising large studies, notes that transport is usually less than 10% of a food's emissions and about 6% across EU diets; what you eat matters far more than how far it travelled, with air-freighted fresh produce the main exception. Second, home-grown is not automatically more nutritious than shop-bought; well-handled frozen vegetables, for example, can hold their nutrients well. The real gains of a backyard greenhouse are freshness, a longer season, lower grocery bills for the crops you grow, and a better understanding of food itself.

For a more ambitious design, see our look at the Greenhouse of the Future building guide.

Sources: NMSU Cooperative Extension, Circular 606: High Tunnel Hoop House Construction for New Mexico (rev. 2019); Wikipedia: Polytunnel; Our World in Data, Hannah Ritchie, 2020: You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local; original free plans: DoorGarden, $50 hoop house greenhouse; first shared by Collective Evolution, April 2014.

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