Large Polycarbonate Greenhouse | Exaco RIGA

The RIGA large polycarbonate greenhouse is built for gardeners who grow through winter. German-engineered with 8mm twin-wall panels and heavy-gauge aluminum framing, this greenhouse handles heavy snow loads, temperature swings, and intense UV—while keeping your plants thriving from January through December.

We offer three sizes in the RIGA series, from 102 to 165 square feet of protected growing space.

Why Choose a Large Polycarbonate Greenhouse?

Glass greenhouses look beautiful until the first hailstorm. Polycarbonate changes everything.

• Superior insulation. The RIGA's twin-wall polycarbonate traps air between layers, creating natural insulation that holds heat far better than single-pane glass. You'll spend less on heating and extend your growing season on both ends.
• Virtually unbreakable. Polycarbonate is 200 times stronger than glass. Hail, wind-blown debris, an errant baseball—your greenhouse keeps standing.
• Diffused light. Unlike glass, polycarbonate scatters sunlight evenly throughout the structure. No hot spots, no scorched leaves, better growth across every shelf and bed.
• UV protection built in. The glazing blocks harmful UV rays while letting growth-promoting light through, protecting both your plants and extending the life of the panels themselves.

RIGA Large Polycarbonate Greenhouse Features

Every RIGA greenhouse ships from the Hoklartherm factory in Germany, where they've been perfecting greenhouse construction for decades. Here's what sets this large polycarbonate greenhouse apart:

• Heavy-duty aluminum frame. 13-gauge extruded aluminum won't rust, rot, or warp. The commercial-grade construction handles snow loads that would collapse lesser greenhouses.
• 8mm twin-wall side panels, 10mm gable ends. Thicker polycarbonate where it matters most—the gable ends take the brunt of wind and weather.
• Automatic roof vents. No electricity needed. Heat-activated pistons open the vents when temperatures rise and close them as things cool down. You get proper ventilation without constant monitoring.
• Barn-style locking door. The 30" x 79" hinged door provides easy access for wheelbarrows, potting benches, and armloads of harvest.
• Roof-hung shelving system. Floor space stays clear for beds, pots, and walkways. The overhead shelving keeps seedlings at working height and maximizes your square footage.

Available Sizes

RIGA 3 - 10'6" L × 9'8" W × 7'7" H 102 sq. ft.

• 3 Panels
• 1 Automatic Roof Vent
• 1 Barn Style Hinged Door w/Lock
• 1 roof window w/ automatic opener
• 1 large rear wall window

RIGA 4 - 14' L × 9'8" W × 7'7" H 135 sq. ft. 2 Automatic Roof Vents

• 4 Panels
• 1 Automatic Roof Vent
• 1 Barn Style Hinged Door w/Lock
• 2 roof window w/ automatic openers
• 1 large rear wall window

RIGA 5 - 17'6" L × 9'8" W × 7'7" H 165 sq. ft.

• 5 Panels
• 1 Automatic Roof Vent
• 1 Barn Style Hinged Door w/Lock
• 4 roof window w/ automatic openers
• 1 large rear wall window

All three sizes include one large rear wall window for cross-ventilation and a barn-style hinged door with lock.

Optional Accessory Kit

Add the accessory kit to maximize your growing space from day one:

• Top shelf (10" wide) – Perfect for seed trays and small pots
• Bottom shelf (25" wide) – Larger plants and overwintering containers
• Foundation frame – Buries in a trench for secure anchoring when you're not mounting to concrete

Shelf lengths match your greenhouse size. Foundation frames available for all RIGA models.

Built for Cold Climates and Four-Season Growing

This large polycarbonate greenhouse is engineered for harsh conditions. High winds, heavy wet snow, hail, and extreme UV exposure—the RIGA handles what lesser structures can't.

The Gothic arch design sheds snow naturally. Loads slide off rather than accumulating and stressing the frame. The aluminum construction won't crack when temperatures swing from warm afternoons to freezing nights. And the polycarbonate glazing carries a 10-year warranty (prorated after year 5) because it's built to last through seasons of real use.

Whether you're growing in Zone 4 or Zone 7, you get a structure that extends your season by months and protects your investment year after year.

Who This Greenhouse Is For

You start seeds in January. You're tired of paying grocery store prices for vegetables you could grow better yourself. You want to walk into a warm, green space when there's snow on the ground.

The RIGA large polycarbonate greenhouse gives you control over your growing season. Extend it by months on each end. Grow crops that don't survive Colorado's late frosts. Create a space that's part garden, part retreat.

Ready to Order?

Select your size above and add to cart—or contact us with questions. We're an authorized Exaco retailer, and every greenhouse ships with our support behind it.

Denver-area gardeners: Ask about our professional greenhouse assembly service.

South Table Sheds ships premium greenhouse kits nationwide. In the Denver metro area, we provide expert assembly and custom shed building backed by 17 years of Colorado experience.