Riga 5 9x17 Greenhouse

Riga 5 9x17 Greenhouse – 165 sq ft | German-Made | Year-Round Growing

The Riga 5 (Riga V) is the second-largest model in the Riga greenhouse series — a serious, German-engineered year-round growing structure with 165 sq ft of growing space, 8mm twin-wall polycarbonate panels, and the iconic "onion" arch profile that sheds snow, maximizes headroom, and minimizes wind resistance. Designed and manufactured in Germany by a company with 28 years of experience, the Riga 5 is built for gardeners who want a true four-season greenhouse, not just a season extender.

Key Features

• 8mm UV-coated twin-wall polycarbonate panels on sides and roof — superior insulation and light diffusion
• 10mm twin-wall polycarbonate panels on front and rear — added strength at the most exposed surfaces
• 4 roof windows (40" W × 24" D each) with automatic openers — passive ventilation, no electricity required
• 1 oversized rear wall window (30" W × 42" H) with adjustment arm — additional cross-ventilation
• Heavy-duty Dutch barn-style door with keyed lock (30" wide × 72" tall) — wheelbarrow-friendly, pest-resistant
• Unique "onion" arch profile — prevents snow buildup, maximizes interior headroom, minimizes wind resistance
• First-class insulation: R/K-value up to 1.89
• Wind-tested to 100 mph when properly anchored
• 15-year warranty on aluminum frame | 10-year pro-rated warranty on polycarbonate panels
• Ships in 1–2 weeks

Why the "Onion" Arch Profile?

The Riga 5 distinctive curved arch profile — nicknamed the "onion" shape — is not just aesthetic. It delivers three structural advantages over conventional peaked or gothic-arch greenhouses:

• Snow shedding — the curved profile causes snow to slide off naturally rather than accumulating, reducing structural load in heavy snowfall regions
• Maximum headroom — the arch shape maximizes usable interior height across the full width of the greenhouse, not just at the peak
• Wind resistance — the rounded profile reduces wind drag compared to flat-sided structures, contributing to the 100 mph wind rating

Riga Series Comparison - Which model is best for you?

Frequently Asked Questions

What is the Riga 5 greenhouse?
The Riga 5 is the second-largest model in the Riga greenhouse series, manufactured in Germany. It features a distinctive curved "onion" arch profile, 8mm and 10mm twin-wall polycarbonate glazing, 4 automatic roof vents, and a 15-year frame warranty. At 165 sq ft, it’s designed for serious year-round growing in all climates.

Is the Riga 5 a true four-season greenhouse?
Yes. The Riga 5 is engineered for year-round use, not just season extension. The 8mm polycarbonate panels provide an R/K-value up to 1.89, the no-eaves arch profile sheds snow naturally, and the structure is wind-tested to 100 mph. With supplemental heating in colder climates (USDA zones 4–6), it can maintain frost-free growing conditions year-round.

Is the base kit required?
A proper foundation is required for dirt installations. The Riga 5 foundation frame is the recommended solution and is designed specifically for the Riga 5 footprint. Without the foundation frame, you will need to provide an alternative foundation (concrete or wood). 

How long does assembly take?
Assembly takes approximately one full day for two people. Written instructions are included. No specialized tools are required, but having two people is strongly recommended for panel handling and frame alignment.

What is the warranty on the Riga 5?
The Riga V includes a 15-year warranty on the aluminum frame and a 10-year pro-rated warranty on the polycarbonate panels. These are among the strongest warranties available on residential greenhouse structures and reflect the quality of German manufacturing.