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    17x17 Janssens Gigant Hobby Greenhouse

    Experience the ultimate in professional greenhouse growing with the Janssens Gigant 17x17 Hobby Greenhouse. Unmatched strength, superior construction, and custom sizing options make this greenhouse a must-have for serious gardeners. Grow year-round with confidence and peace of mind with our 13-year warranty.

    More Sizes:

    Select your Colour:

    Add Staging and Doors?

    Qty 1
    Janssens Silver Seed Tray Shelving
    + £295
    Qty 1
    £15 off
    1 Tier Staging Colour Matched
    + £74
    Qty 1
    Janssens Integrated Colour Matched Shelving
    + £55
    Qty 1
    £23 off
    2 Tier Staging Colour Matched
    + £96
    Qty 1
    £10 off
    Top Tier Staging Extension Colour Matched
    + £49
    Qty 1
    Qty 1
    Additional Double Hinged Door
    + £799
    Qty 1

    Staging and Doors information

    Janssens Silver Full Length Integrated Staging - £105.00
    Janssens Silver Full Length Integrated Staging

    Add the Silver Full Length 458cm long integrated shelving to the side of your greenhouse to help retain your floor space


    Janssens Silver Seed Tray Shelving - £295.00
    Janssens Silver Seed Tray Shelving

    Add the Silver Full Width 458cm long Seed Tray Shelving to the rear of your greenhouse to help retain your floor space


    1 Tier Staging Colour Matched - £74.00
    1 Tier Staging Colour Matched

    This 1 Tier Vitavia Colour Matched greenhouse staging gives you a handy work surface and storage area. Dimensions: 76cm (H) x 50cm (D) x 120cm (W)


    Janssens Integrated Colour Matched Shelving - £55.00
    Janssens Integrated Colour Matched Shelving

    Add the Colour Matched 150cm long x 23cm wide integrated shelving to your greenhouse to help retain your floor space


    2 Tier Staging Colour Matched - £96.00
    2 Tier Staging Colour Matched

    This 2 Tier Vitavia Colour Matched greenhouse staging gives you a handy work surface with additional low level storage. Dimensions: 76cm (H) x 50cm (D) x 120cm (W)


    Top Tier Staging Extension Colour Matched - £49.00
    Top Tier Staging Extension Colour Matched

    This little top level Colour Matched shelf attaches to 1 or 2 Tier staging to give you a bit more storage space


    Janssens Silver Integrated Staging - £80.00
    Janssens Silver Integrated Staging

    Add the Silver 150cm long x 53cm wide integrated staging to your greenhouse to help retain your floor space


    Additional Double Hinged Door - £799.00
    Additional Double Hinged Door

    Add more access points to your greenhouse with an additional set of double doors


    Add Ventilation and Shading?

    Qty 1
    Curtain Shading
    + £27
    Qty 1
    Louvre Vent
    + £79
    Qty 1
    Janssens Sunscreen Shading
    + £129
    Auto Louvre Opener
    + £40
    Qty 1

    Ventilation and Shading information

    Auto Roof Vent Opener - £39.00
    Auto Roof Vent Opener

    This automatic opener for your roof vents will automatically open your roof vents to ventilate your greenhouse when it becomes too hot.


    Curtain Shading - £27.00
    Curtain Shading

    Curtain shading will protect your plants from sun scorch and provide shade to moderate temperature. 6ft x 8ft.


    Louvre Vent - £79.00
    Louvre Vent

    A louvre window brings fresh cool air into your greenhouse to moderate the temperature inside. An essential add on.


    Janssens Sunscreen Shading - £129.00
    Janssens Sunscreen Shading

    Add the Janssens retractable shading kit for ease of use


    Auto Louvre Opener - £40.00
    Auto Louvre Opener

    This automatic opener mechanism will open your louvre window for you when you’re not around. No need to worry about ventilation, this does it automatically for you! (Does not include louvre window).


    Add Extras?

    Hygrometer
    + £17
    Soil Thermometer
    + £29
    Max/Min Thermometer
    + £23
    100L Mini Rainsaver Water Butt
    + £54
    Qty 1

    Extras information

    Hygrometer - £17.00
    Hygrometer

    This Hygrometer will measure the humidity levels inside your greenhouse.


    Soil Thermometer - £29.00
    Soil Thermometer

    This Soil Thermometer will let you track the temperature of your soil inside the greenhouse.


    Max/Min Thermometer - £23.00
    Max/Min Thermometer

    This thermometer will tell you your maximum daytime temperature as well as record the lowest night time temperature in your greenhouse.


    100L Mini Rainsaver Water Butt - £54.00
    100L Mini Rainsaver Water Butt

    Add this 100L water butt kit that includes: Butt, Tap & Lid - Black Stand


    The 17ft x 17ft Janssens Gigant Hobby Greenhouse will fit all of your professional growing needs perfectly. The vast growing area and super strong construction ensure that you can grow a variety of plants and vegatables year round. You'll get the strongest Aluminium greenhouse on the market with full modern box section construction, vital for weather resistance, especially in very strong storms and winds. Custom lengths are available in 2ft increments so we will have a size to suit all needs.

    All Janssens Gigant Greenhouses are built around a strong box-section aluminium frame, with 4mm Toughened Glass held in with proper rubber glazing gasket to take on the worse of UK weather!

    Can't find the size or specification to suit your needs?

    Most Janssens Greenhouses are fully customisable.

    Call us on 0800 098 8877 for your Free Quote!
    • 5310mm x 5310mm Dimensions (17ft 5" x 17ft 5")
    • 2m High Eaves
    • Aluminium Frame with Tubular and Box Section for Superior Strength.
    • Box Section Base Plinth.
    • Double Hinged Locking Doors - Outward Opening
    • 4mm Full Length Toughened Safety Glass
    • Rubber Glazing Gasket Strips (no fiddly clips)
    • 4x Roof Vents
    • 11 Blade Louvre Vent
    • Gutters and 40mm Aluminium Downpipes.
    • Stainless Steel Fittings.
    • Step by Step Instruction Manuals with Instructional DVD.
    • 13 Year Manufacturers Warranty.
    • Many Accessories Available - Scroll down this page.
    • Please call us for custom lengths.

    Delivery is currently within 8 weeks for Urban Models, 10-12 Weeks for Master Models and 16 weeks for all other models to UK Mainland. Your exact delivery day will be confirmed with you at least 3 days before the day by telephone.

    Please note Some Scottish postal codes are subject to delivery charges.

    Optional Installation information: Installation will be carried out around 14-21 working days after delivery. Optional Installation will only be carried out on a surface of slabs or concrete and only with the recommended base plinth. You may be charged for accessories Installation is for the Greenhouse only and does not include staging, accessories etc

    Greenhouse Size Diagram

    Greenhouse Dimensions

    A: Greenhouse width

    5310mm (17′ 5″)

    B: Greenhouse depth

    5310mm (17′ 5″)

    C: Ridge height

    3150mm (10′ 4″)

    D: Eaves height

    2040mm (6′ 8″)

    E & F: Door Size

    700mm (2′ 3″) x 2000mm (6′ 6″) (aperture)

    Minimum size for your greenhouse base:

    5310mm (17′ 5″) x 5310mm (17′ 5″)

    Palram Silver Steel Base
    Included with ALL Janssens Greenhouses.

    The Janssens Foundation Base eliminates the need for a full concrete foundation. Simply assemble your greenhouse and secure it with our quick 4-corner anchoring system!

    Premium 4mm Toughened Glass

    JANSSENS delivers superior protection with our full-length 4mm toughened glass. Six times stronger than ordinary glass, it offers exceptional durability and safety. Enjoy crystal-clear views and peace of mind, knowing you're shielded by the industry's safest greenhouse glass. Polished edges ensure easy, safe assembly, letting you focus on what truly matters – your thriving garden.

    Janssens Glazing Gasket
    Weather-Tight Seal: Superior Protection Guaranteed

    Don't let wind effect your investment with Janssens state-of-the-art glazing system. Featuring:

    • Advanced rubber strip technology
    • Unbeatable water and wind resistance
    • Seamless, long-lasting seal
    Janssens Glazing Bars
    Industry-Leading Strength in Every Frame

    Janssens cutting-edge tubular aluminium glazing bars are among the sturdiest in today's greenhouse market. Enjoy peace of mind knowing your investment is protected by top-tier materials that outlast and outperform the competition!

    Janssens Roof Ridge Profile
    Built to Last: Premium Stainless Steel Hardware

    Every bolt, nut, and fitting in your JANSSENS greenhouse is crafted from top-quality stainless steel to withstand the elements,

    Janssens Roof Ridge Profile
    Smart Water Management System Included

    Maximize your growing potential with our comprehensive water control solution:

    • Efficient gutters to collect rainwater
    • Clever condensation channels to manage humidity
    • Large 40mm downpipes for rapid drainage
    Janssens Instructions
    Effortless Assembly at Your Fingertips

    Set up your new greenhouse with ease. Every model includes:

    • Detailed step-by-step manual
    • Comprehensive assembly video
    Janssens Qualicoat Powder Coating
    Lasting Beauty: Premium Powder-Coated Finish

    Janssens only use Qualicoat-certified powder coating on all of their Greenhouse products. This high-quality finish ensures your JANSSENS greenhouse stays stunning for years. Contact us for custom RAL colours.

    Janssens Greenhouse
    Janssens Greenhouses

    Janssens Greenhouses were established in 1946 in Lier, Belgium and is now a super modern 6500sqm production facility equipped with the very latest high-tech automated machinery. Many years of production and the very latest design and manufacturing processes make a Janssens Greenhouse one of the best high end greenhouses you can buy today.

    Janssens Greenhouse 13 Year Warranty
    13 Year Warranty

    Janssens greenhouses come with a 10-year warranty on the greenhouse frame. This warranty covers any manufacturing defects in materials or workmanship. However, it does not cover glass or polycarbonate. The warranty is only valid if the greenhouse is assembled according to the provided instructions.