Junior Victorian
Compact rectangular family with 4 mm tempered safety glass, tubular aluminum framing, sliding door and automatic roof-vent openers in the configurations we track.
Home Janssens Greenhouses: Junior Victorian & Premium Glass Lines
Janssens Greenhouses: Junior Victorian & Premium Glass Lines
Janssens ranges from compact tempered-glass hobby greenhouses to larger Victorian, modern, hybrid and special-order structures. Compare the exact family, glazing, dimensions, ventilation and project complexity before treating the brand as one product.
Janssens spans compact glass kits to custom garden structures
Janssens is a Belgian greenhouse manufacturer with a much broader lineup than the three Junior Victorian models currently normalized by GreenhouseMatch. Exaco's current catalog includes Junior Victorian, Royal Victorian, Modern, Cathedral, Retro Victorian, Gigant/High Gigant, Arcadia/Arcadia Plus and multiple orangerie/special-order formats, plus a Royal Victorian Hybrid line.
That breadth matters because “Janssens greenhouse” can mean a compact 4 mm tempered-glass hobby greenhouse, a larger premium Victorian structure, a single-slope Modern greenhouse, a wall-attached Arcadia or a custom reinforced project. The right comparison begins with structure and glazing—not with the brand name alone.
Royal Victorian
Larger traditional greenhouse family. Useful when the buyer wants premium glass architecture beyond the Junior footprint.
Modern
Single-slope/pent-roof design using 4 mm tempered glass. Current Exaco specs include flexible door placement and multiple natural-ventilation openings.
Hybrid / special order
Royal Victorian Hybrid, Arcadia and configurable structures show why Janssens cannot be reduced to “Victorian glass greenhouse.”
Junior Victorian 23, 24 and 25: normalized comparison
| Configuration | Actual size stored | Floor area | Factory ventilation stored |
|---|---|---|---|
| Junior Victorian 23 | About 7'9" × 10'2"; 8'2" peak | 79 sq ft | 1 roof vent + 1 automatic roof opener |
| Junior Victorian 24 | About 7'9" × 12'7"; 8'2" peak | 96 sq ft | 2 roof vents + 2 automatic roof openers |
| Junior Victorian 25 | About 7'9" × 15'; 8'2" peak | 116 sq ft | 2 roof vents + 2 automatic roof openers |
All three current GreenhouseMatch records use 4 mm full-pane tempered safety glass and a 17-gauge tubular aluminum frame. The family is not expandable in our current data, so choosing enough length at purchase matters more than it does for an extendable tunnel-style greenhouse.
Janssens vs polycarbonate is not just an appearance choice
The Junior Victorian's full-pane tempered glass offers clarity and traditional architecture, while many residential polycarbonate competitors use twin-wall or multiwall panels that trap air and can reduce conductive heat loss. That can affect heater size, winter operating cost, light diffusion and impact behavior.
Use Glass vs Polycarbonate for the material-level tradeoff, then return to exact models. A premium glass greenhouse can still require substantial summer ventilation, shade and winter heat. The material name does not answer those operating questions by itself.
Compare the three Junior Victorian configurations
See the exact floor area and ventilation differences first, then browse premium glass alternatives separately if glass remains the right construction choice.
The broader Janssens catalog increases project complexity
The current Modern page, for example, lists a shed-style roof, 4 mm tempered glass, 17-gauge aluminum framing, roof vents, push-out side windows and louvre windows. Exaco explicitly notes that model complexity can make professional assembly sensible. Arcadia adds host-wall attachment and special-order customization, which moves the project closer to an architectural addition than a simple freestanding kit.
For permitting, Exaco recommends resolving local requirements before ordering when snow/wind loads may require additional reinforcements. For special-order/custom greenhouses, Exaco also states that structural certification is not one-size-fits-all. GreenhouseMatch therefore does not assign a generic Janssens snow/wind rating.
When Janssens belongs on the shortlist
- Premium glass preference: especially when clarity, traditional architecture and garden appearance are important.
- Permanent-project mindset: buyers prepared to plan foundation, assembly, freight and climate systems as one project.
- Custom/special-order needs: the broader Janssens line goes well beyond standard rectangular kits.
- Not ideal for a simple lightweight seasonal kit: if low complexity and easy relocation dominate, another product class may fit better.
Use the Project Cost Calculator before treating an observed kit price as the project budget, and use the Heater Calculator if glass-envelope heat loss matters to your season-extension goal.
Glass changes the light, heat and installation tradeoff
Janssens' glass families are attractive to buyers who want a bright, permanent greenhouse with traditional or architectural styling. The practical consequence is that the glazing is also heavier than polycarbonate and the current Junior Victorian records use single 4 mm tempered panes rather than a multiwall air-space panel. That makes the foundation, assembly method and heating plan worth considering early rather than after the greenhouse has been selected.
Tempered glass improves safety behavior compared with ordinary annealed panes, but it does not turn the greenhouse into an impact-proof structure. Likewise, the clear glazing does not remove the need for shade or ventilation in summer. Use the exact vent package and greenhouse volume when planning cooling, and use the actual glass covering class when estimating winter heat loss.
Junior Victorian size choice is mostly a length decision
The three normalized Junior Victorian configurations share roughly the same width and peak height, while length and floor area increase from the 23 to 24 to 25. That makes the choice unusually easy to frame: determine whether the fixed width works for the planned bed/bench-and-aisle layout, then choose enough length for crop zones, potting space and circulation.
Because these records are not marked expandable, leaving too little length can be harder to correct later than it would be with an explicitly extendable greenhouse family. The Size Calculator can estimate required floor area before you compare the 79, 96 and 116 sq ft configurations, and the exact comparison keeps the vent counts and dimensions visible together.
Primary product sources
- Exaco — Junior Victorian ↗current dimensions, glass and ventilation package.
- Exaco — Glass Greenhouses ↗current Janssens family context.
- Exaco — Modern ↗current single-slope Janssens specifications and assembly guidance.
- Exaco — Arcadia / Arcadia Plus ↗current lean-to/custom structural-certification guidance.
- How GreenhouseMatch verifies greenhouse specificationsSource hierarchy, verification dates and treatment of missing or conflicting specifications.
Frequently asked questions
Who makes Janssens greenhouses?
Janssens greenhouses are manufactured in Belgium. Exaco distributes and supports Janssens greenhouses in North America.
Are Janssens greenhouses glass?
Many Janssens greenhouse families use 4 mm tempered glass, including the Junior Victorian and Modern examples. Janssens also offers hybrid/polycarbonate configurations, so the brand should not be treated as glass-only.
What is the Junior Victorian greenhouse?
The Junior Victorian is a compact Janssens glass family. The current Exaco page lists three standard sizes and GreenhouseMatch normalizes those configurations for exact comparison.
Are Janssens greenhouses easy to assemble?
Assembly complexity depends heavily on the model and options. Exaco notes that many Janssens greenhouses can be DIY projects for handy owners, while larger models, hinged doors, knee walls, cupolas and other complex configurations may be better suited to professional assembly.