Exaco vs. Riga Greenhouses: Which Premium Kit Is Worth It?

Exaco (Janssens Royal Victorian and similar lines) and Riga (by Hoklartherm) are two of the most respected names in premium hobby greenhouse kits. Both use thick-gauge aluminum frames with twin-wall polycarbonate panels, and both are engineered for northern climates with serious snow loads. The differences lie in the details — and for a purchase in the $3,000 to $10,000 range, details matter.

Frame Construction

Exaco's Janssens-branded greenhouses use Belgian-engineered aluminum extrusions with a dark green or raw aluminum finish. Frame members are thick (1.5 to 2.0 inch) and slot together with bolted connections. The frames feel substantial and lock panels securely. Riga greenhouses use German-engineered aluminum with an anodized finish that resists corrosion better than painted aluminum. Riga's frame cross-sections are designed with internal channels that lock polycarbonate panels from the inside, creating a smoother exterior profile that sheds snow more effectively.

Glazing

Exaco models typically come with 4mm twin-wall polycarbonate — the industry standard for hobby greenhouses. Some premium Exaco models offer 10mm or 16mm options at additional cost. Riga greenhouses ship with 8mm or 10mm twin-wall polycarbonate as standard — a meaningful insulation advantage (R-1.7 vs R-1.4 for 4mm) that translates directly to lower heating costs in cold climates. The thicker glazing also provides better rigidity and impact resistance.

Snow and Wind Ratings

Riga greenhouses are engineered for German and Scandinavian snow loads — typically 25 to 35 psf, among the highest in the hobby greenhouse market. Exaco's Janssens models are rated at 20 to 25 psf depending on the model. Both exceed the 15 psf minimum recommended for northern US climates, but Riga's higher ratings provide more margin in regions with heavy, wet snow.

Ventilation

Exaco models typically include 1 to 2 roof vents and a single door. Riga greenhouses include 2 to 4 roof vents (depending on size) plus louver vents in the base walls for passive air intake. The additional ventilation in Riga models provides better summer cooling without add-on purchases. Both brands support aftermarket automatic vent openers.

Price and Value

Riga greenhouses cost 20 to 40 percent more than comparable Exaco models for similar footprints. A Riga III (10 × 17 feet) runs approximately $5,000 to $6,000; a comparable Exaco Janssens Royal Victorian runs $3,500 to $4,500. The Riga premium buys you thicker standard glazing, higher snow load ratings, more ventilation, and German engineering. Whether this premium is worth it depends on your climate (heavy snow and wind favor Riga) and your budget. Both brands produce greenhouses that will last 20+ years with proper maintenance.

Customer Experience and Assembly

Both Exaco and Riga greenhouse kits are designed for homeowner assembly, but the experience differs. Riga's German-engineered panel-locking system slots panels into internal frame channels, creating a clean exterior profile with no exposed fasteners. Many owners report that Riga assembly is intuitive once the first few panels are in place — the system essentially guides you. Assembly time for a mid-sized Riga (10 × 17 feet) is typically 2 to 3 days for two people.

Exaco's Janssens line uses a more traditional bolt-and-clip assembly. Panels are secured with external clips and stainless steel hardware. This approach provides easy panel replacement (each panel is independently removable) but creates more potential for air leaks at clip points and requires careful alignment during assembly. Typical assembly time is 3 to 4 days for two people.

Warranty and Support

Riga offers a 15-year frame warranty and 10-year glazing warranty — among the best in the industry. Exaco offers a 10-year frame warranty and a 5-year glazing warranty. Both brands sell replacement parts directly. Riga's customer support is US-based (they import from Germany but maintain a US warehouse and support operation); Exaco also maintains US-based support with parts inventory. In both cases, the frame is essentially a lifetime investment — aluminum does not corrode in greenhouse conditions. The glazing is the wear item that eventually needs replacement, and both brands make that replacement straightforward.

Ultimately, both Exaco and Riga represent significant investments in greenhouse infrastructure that will serve growers for decades. Test-drive both brands if possible by visiting a greenhouse dealer or fellow grower who has either installed. The feel of the materials, the fit of the panels, and the overall build quality are best assessed in person rather than from specifications alone.