Riga S
Compact bell-shaped family about 7'8" wide. Current Exaco specifications list 2s, 3s and 4s sizes.
Home Riga Greenhouses: Riga S, Riga & Riga XL Compared
Riga Greenhouses: Riga S, Riga & Riga XL Compared
Riga greenhouses share a recognizable curved design, but the compact S, standard Riga and much larger XL families have meaningfully different widths, panel construction, ventilation packages and project requirements.
Riga is a family: S, standard and XL are materially different sizes
Riga greenhouses are made by Hoklartherm in Germany and distributed in North America by Exaco. The visual language is consistent—curved sidewalls, aluminum framing and rigid polycarbonate—but the families scale from compact hobby structures to a 14-foot-wide premium greenhouse.
The standard Riga and Riga S families currently use 8 mm twin-wall polycarbonate on the side walls and 10 mm twin-wall polycarbonate at the gable ends. Riga XL increases the envelope to 16 mm triple-wall polycarbonate on side walls and gable ends. That makes “Riga greenhouse” too broad for heating, foundation or layout planning without the actual family and size.
Riga
Standard bell-shaped family about 9'8" wide. Current Exaco specifications list Riga 3, 4 and 5.
Riga XL
Full-size family about 14' wide with 16 mm triple-wall polycarbonate and substantially larger floor areas.
Ventilation package
Roof vents, automatic openers and rear-window ventilation are part of the current family story, but quantities scale with exact size.
Riga S vs Riga: current exact-size examples
| Configuration | Width × length | Floor area | Factory ventilation stored |
|---|---|---|---|
| Riga 3s | 7'8" × 10'6" | 81 sq ft | 1 roof vent + rear window; 1 automatic roof opener |
| Riga 4s | 7'8" × 14' | 108 sq ft | 2 roof vents + rear window; automatic opener data varies by current record/source |
| Riga 3 | 9'8" × 10'6" | 102 sq ft | 1 roof vent + rear window; 1 automatic roof opener |
| Riga 4 | 9'8" × 14' | 135 sq ft | 2 roof vents + rear window; 2 automatic roof openers |
| Riga 5 | 9'8" × 17'6" | 165 sq ft | 4 roof vents + rear window; 4 automatic roof openers |
Notice how the nominal “8-foot” or “10-foot” shopping category does not equal the actual outside width. The difference matters for setbacks, prepared foundations and tight side-yard locations.
Riga XL belongs in a different project class
Exaco currently lists Riga XL at 14 feet wide with a 9'10" peak height. The family spans roughly 16'5" to 29'6" in listed lengths, with larger vent counts as the greenhouse gets longer. The current XL page also calls out a 13-gauge aluminum frame, barn-style locking doors and 16 mm triple-wall polycarbonate.
GreenhouseMatch has not yet normalized an XL configuration into the Finder because our launch catalog intentionally prioritizes a representative set rather than every product. If you are considering XL, use Exaco's current dimensions as the starting point and enter the exact geometry manually in the heating/ventilation/project-cost tools until a normalized record is added.
Compare the Riga sizes already in GreenhouseMatch
See the compact and standard families side by side before deciding whether you need the broader XL project class.
Foundation and anchoring are part of the Riga decision
Exaco's current Riga guidance says the greenhouse site must be level and securely anchored. It describes a concrete strip foundation or a compatible foundation/base frame system as primary approaches and notes that local permitting/load requirements may require additional reinforcement. That is important context: curved walls and thick polycarbonate do not make foundation planning optional.
Before ordering, reconcile the exact outside dimensions with the Project Cost Calculator. Include site preparation, base/foundation, anchoring, freight, assembly, heater, ventilation and electrical/water work separately rather than treating the kit price as the finished project.
Where Riga is strongest—and where another family may fit better
- Strong shortlist: buyers prioritizing a premium rigid polycarbonate envelope, automatic natural ventilation, curved geometry and documented exact dimensions.
- Cold-climate interest: thicker multiwall construction makes Riga especially relevant to the cold-climate selection process, but actual heat load still needs calculation.
- Premium glass preference: a Janssens greenhouse may be a more natural comparison if clarity and Victorian architecture are primary.
- Published numeric load requirement: GreenhouseMatch's current Riga records do not contain a defensible standardized psf/mph figure. Do not substitute marketing language for the exact documentation your permit/site requires.
Thicker panels do not remove the need for ventilation planning
Riga's multiwall polycarbonate construction is relevant to heat retention, but a greenhouse that retains heat more effectively can still overheat rapidly under strong sun. The current family specifications include roof vents, automatic openers and rear-window ventilation, which are useful features; GreenhouseMatch still treats those as documented openings rather than proof that a particular summer site has enough airflow.
Use the Ventilation Calculator with the selected model or exact dimensions to estimate an airflow target. For a heated greenhouse, use the Heater Calculator with the correct panel class and exposed geometry. This makes the comparison between Riga S, standard Riga and Riga XL about the complete operating system rather than simply choosing the thickest available panel.
Primary product sources
- Exaco — Riga S ↗current compact-family dimensions, glazing and ventilation.
- Exaco — Riga ↗current Riga 3/4/5 dimensions and specifications.
- Exaco — Riga XL ↗current 14-foot-wide family and 16 mm triple-wall construction.
- Exaco — Greenhouse catalog ↗current family context.
- How GreenhouseMatch verifies greenhouse specificationsSource hierarchy, verification dates and treatment of missing or conflicting specifications.
Frequently asked questions
Who makes Riga greenhouses?
Exaco identifies the Riga series as manufactured by Hoklartherm in Apen, Germany and distributed/supported in North America by Exaco.
What is the difference between Riga S, Riga and Riga XL?
Riga S is the compact family at about 7 feet 8 inches wide, standard Riga is about 9 feet 8 inches wide, and Riga XL is about 14 feet wide. The current XL specification also moves to 16 mm triple-wall polycarbonate rather than the 8/10 mm twin-wall combination used on the smaller families.
Do Riga greenhouses include automatic roof vents?
Current Exaco specifications for Riga S, standard Riga and Riga XL include roof vents and automatic roof-vent openers, with quantities depending on model size. Exact kit contents should still be verified before purchase.
Does GreenhouseMatch store a numeric Riga snow or wind rating?
Not in the current normalized Riga records. Exaco describes the structures as designed for challenging conditions and discusses reinforcement/local requirements, but GreenhouseMatch does not convert qualitative claims into an invented psf or mph value.