Janssens Greenhouses

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.

Whether you're after a traditional Victorian design with ornate cresting or a sleek contemporary orangery greenhouse, the Janssens range offers fully customisable options. Free UK mainland delivery is included on all models. Most customers choose mid-range models like the Helios Master (£4,500-£7,000) or Helios Retro (£5,000-£8,500). For serious growers seeking the ultimate in durability, Janssens aluminium greenhouses deliver unmatched structural integrity.

Janssens Greenhouse Buyer's Guide

Size & Eaves Height
Size matters with Janssens. The compact Urban range suits smaller gardens with its 181cm eaves height, perfect for patios (£3,300-£5,000). Standard growing greenhouses like the Helios Master span 2.5m to 5m wide, offering 170-200cm eaves height (£4,500-£9,000). Professional growers should explore the Gigant series, which extends up to 6m x 12m (£10,000+). Need extra headroom for tall plants? Choose models with 200cm+ eaves height.

Budget & Long-Term Value
Janssens greenhouses cost more upfront, but this premium buys exceptional value. The 13-year structural warranty outlasts competitor guarantees by 3-5 years. The 4mm toughened glass reduces storm damage risk by approximately 85% compared to 3mm glazing. Stainless steel fittings eliminate the corrosion maintenance that plagues cheaper greenhouses after 3-4 years. When factored over 15 years, Janssens delivers better cost-per-year value than budget alternatives requiring replacement.

Key Quality Indicators
Look for three quality indicators:

1. Tubular Frame Profiles: Not flat box-sections.
2. Full-Length Glass: No overlapping sections that trap dirt.
3. Powder-Coated Finish: In Victorian green or matt black for total weather protection.

The Helios range also includes weather-tight rubber seals as standard, blocking 95% of draughts.

Customisation
Our customers particularly value the bespoke service. Adjust any Janssens greenhouse by 30cm increments, add extra vents and doors, select styling, and choose colours. Connect with our large greenhouses expertise by calling 0800 098 8877 for a custom quotation.

Frequently Asked Questions

• How much do Janssens greenhouses cost?

  Janssens greenhouses range from £3,300 for the entry-level Urban 2.5m x 2.5m model 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, 4mm toughened safety glass, and free UK mainland delivery.

• What makes Janssens different from cheaper alternatives?

  The tubular aluminium frame provides 60% greater wind resistance than standard box-section profiles. Every Janssens uses 4mm toughened safety glass, which is 6 times stronger than 3mm glass. Finally, stainless steel fixings throughout prevent the rust and corrosion common in cheaper greenhouses after just 3-4 years.

• How difficult is it to install a Janssens greenhouse?

  Janssens greenhouses are precision-engineered for a perfect fit, which makes assembly 30-40% faster than mass-market kits. However, due to the weight of the 4mm glass and the value of the structure, we recommend professional installation. A 2-person professional team typically completes an installation in 1-2 days. DIY installation is possible for highly experienced individuals with 2-3 days to dedicate to the project. Professional installation costs range from £500-£800.

• How long does a Janssens greenhouse last?

  The 13-year warranty is the industry's longest, but a typical lifespan extends 25-30 years with minimal maintenance. The powder-coated aluminium frames and stainless steel fittings resist corrosion indefinitely. This exceptional longevity delivers superior long-term value.

• 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 colour-fastness. It guarantees the greenhouse against defects in materials and manufacturing. It does not cover accidental damage, moving parts (like vent openers, which have a separate 1-year guarantee), or glass breakage from impacts.

• Can I customise a Janssens greenhouse?

  Yes, customisation is a key feature. Adjust dimensions in 30cm increments, add extra roof vents (£80+), louvre windows (£120+), or upgrade to automatic vent openers (£150-£200). Choose powder coating in Victorian green, matt black, or custom RAL colours (£400-£600 supplement). You can even combine modules to create T-shaped configurations or add lean-to greenhouses extensions.

• Do Janssens greenhouses need planning permission?

  Most Janssens greenhouses do not require planning permission under UK permitted development rights. Standard freestanding greenhouses under 2.5m high and positioned 2m+ from boundaries are typically exempt. However, always check with your local planning authority before ordering, especially for dwarf wall models, structures in conservation areas, or those exceeding 4m height.

• What accessories do I need for a Janssens greenhouse?

  Essential greenhouse accessories include automatic vent openers, greenhouse staging to maximise space, and greenhouse heaters for frost protection. The strong tubular frames can easily support heavy hanging baskets and vine crops. Budget £300-£800 for a well-equipped growing environment.