- 5ft 3" Wide
- Box Section Aluminium Frame
- Single Sliding Door
- 4mm Toughened Safety Glass
- Rubber Glazing Gasket Strips
- 11 Blade Louvre Vent
- Gutters with Downpipes
- Stainless Steel Fittings
- Step by Step Instruction DVD
- 13 Year Manufacturer's Warranty
£30 OFF Everything!
Use code SPRING30 at checkout min order £799 (Everything)
Janssens Greenhouses
Janssens Greenhouses (formerly known as "Helios") are widely considered the strongest aluminium glasshouses in the European market. Hand-crafted in Belgium, they differ from standard greenhouses by using closed-tubular box-section profiles rather than open T-strips. This engineering allows them to hold 4mm toughened safety glass (33% thicker than the industry standard) without flexing, making them the definitive choice for exposed gardens and serious horticulturalists seeking a "forever" structure.
Why Choose a Janssens Greenhouse?
Handcrafted in Belgium since 1946, Janssens greenhouses represent over 75 years of specialist engineering and design excellence. Each greenhouse is manufactured in their state-of-the-art 6,500sqm facility in Lier, combining traditional craftsmanship with modern automated precision. Browse our complete collection of Janssens, from compact Urban models starting from £3,300 to spacious Gigant professional ranges exceeding £10,000.
What sets Janssens apart? Every structure features tubular aluminium frames (not the cheaper box-section profiles many competitors use), 4mm toughened safety glass that's 6 times stronger than standard glazing, and exclusively stainless steel fixings that won't rust or corrode. The 13-year manufacturer's warranty is the longest in the industry.
Janssens Greenhouse Buyer's Guide
Size & Eaves Height: Size matters with Janssens. The compact Urban range suits smaller gardens with its 181cm eaves height. Standard growing greenhouses like the Helios Master span 2.5m to 5m wide. Professional growers should explore the Gigant series.
Key Quality Indicators: Look for three quality indicators:
- Tubular Frame Profiles: Not flat box-sections.
- Full-Length Glass: No overlapping sections that trap dirt.
- Rubber Glazing Gaskets: Weather-tight seals blocking 95% of draughts.
Can't find the size or specification to suit your needs?
Most Janssens Greenhouses are fully customisable. Learn more about our bespoke options.
Call us on 0800 098 8877 for your Free Quote!
Why We Chose This Range
“We stock Janssens for one primary technical reason: The Rubber Glazing Gaskets. Most greenhouses hold glass in place with metal 'W-clips' that can ping off in high winds, causing glass to rattle and break. Janssens presses their 4mm glass against thick rubber weather seals, secured by full-length aluminium capping. This 'automotive-style' glazing means the glass cannot move, rattle, or leak, even in severe UK storms.”
— Matt, Founder of Greenhouse Stores🔧 Matt's Installation Tip: The "Zero-Threshold" Trap
Many Janssens models (like the Helios) feature a low-threshold door, which is brilliant for wheelbarrow access. However, this means you cannot have a base plinth running across the door opening.
When laying your concrete or slab foundation, you must ensure the floor level inside the greenhouse is exactly flush with the external ground level at the door point. If you raise the internal floor too high, the door brushes won't seal. If you set it too low, rain will run under the door. Precision here is key.”
Frequently Asked Questions
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What is the difference between Janssens 'Action' and 'Helios' models?
They use exactly the same high-quality aluminium frame and glass. 'Action' models are pre-packaged kits in set sizes which allows for cheaper pricing and faster delivery. 'Helios' models are made to order, giving you the flexibility to move doors, add windows, and choose custom colours.
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How much do Janssens greenhouses cost?
Janssens greenhouses range from £3,300 for the entry-level Urban models to over £12,000 for large custom Gigant structures. Most UK customers invest £4,500-£8,000 for mid-range Helios Master or Helios Retro models. These prices include the 13-year warranty and free UK mainland delivery.
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What makes Janssens different from cheaper alternatives?
The tubular aluminium frame provides 60% greater wind resistance than standard profiles. Every Janssens uses 4mm toughened safety glass (6x stronger than standard) and secures it with rubber gaskets rather than metal clips, creating a sealed, rattle-free structure.
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How difficult is it to install a Janssens greenhouse?
Janssens greenhouses are precision-engineered, which makes assembly faster than mass-market kits, but they are heavy. A 2-person professional team typically completes an installation in 1-2 days. DIY installation is possible for experienced individuals but requires 2-3 days.
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What does the 13-year warranty cover?
The 13-year manufacturer's warranty covers the structural integrity of the aluminium frame and the powder-coated finish against corrosion or paint failure. It guarantees the greenhouse against manufacturing defects but excludes glass breakage or storm damage.
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