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Use code XMAS50 at checkout min order £999 (Everything)

17x39 Janssens Gigant Victorian Greenhouse

17x39 Janssens Gigant Victorian Greenhouse

Delivery 4-16 weeks ⛟

SAVE £150

Click to enlarge - For illustration purposes.

Janssens Gigant Victorian Greenhouse Green

Janssens 19x19 Gigant Victorian Greenhouse

Janssens 19x25 Gigant Victorian Greenhouse

Janssens Gigant Victorian Greenhouse Side Doors

Janssens Gigant Victorian Dwarfwall Greenhouse Front

Janssens Gigant Victorian Dwarf Wall Greenhouse

Janssens Gigant Victorian Greenhouse Frame

Janssens Gigant Victorian Greenhouse Frame Profiles

Janssens Gigant Victorian Greenhouse Interior

Janssens Gigante Customisable Optional Accessories

Quick Code: P175450

17ft 5" wide x 39ft 2" deep
4mm Full Length Toughened Safety Glass
Extra Strong Aluminium Frame
Choice of Powder Coated Finishes
Double Hinged Door
12 x Roof Vents
6 x Louvre Vent
Includes Box Section Base Plinth
No Clip Rubber Glazing Gasket Strips
Gutters and 40mm Aluminium Downpipes
Stainless Steel Hardware
13 Year Manufacturers Warranty
Contact us for Custom Options on this Model

Greenhouse Dimensions

A: Greenhouse width

5320mm (17′ 5″)

B: Greenhouse depth

11950mm (39′ 2″)

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 11950mm (39′ 2″)

Customise your Greenhouse

Choose your Colour

Black Powder Coated Frame

+ £0

Green Powder Coated Frame

+ £0

White Powder Coating

+ £0

Choose your Colour information

Black Powder Coated Frame - £0.00

Green Powder Coated Frame - £0.00

White Powder Coating - £0.00

Add Ventilation and Shading?

Auto Roof Vent Opener

+ £75

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

Qty 1

Janssens Side Vent Colour Matched

+ £150

Help recirculate the air in your greenhouse with a side vent or two!

Qty 1

Louvre Vent Colour Matched

+ £165

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

Qty 1

Additional Roof Vent Colour Matched

+ £99

Add roof ventilation to your greenhouse to help moderate the temperature

Qty 1

Ventilation and Shading information

Auto Roof Vent Opener - £75.00

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

Janssens Side Vent Colour Matched - £150.00

Help recirculate the air in your greenhouse with a side vent or two!

Louvre Vent Colour Matched - £165.00

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

Additional Roof Vent Colour Matched - £99.00

Add roof ventilation to your greenhouse to help moderate the temperature

Add Staging and Doors?

Janssens Colour Coded Full Length Integrated Staging

+ £135

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

Qty 1

Janssens Colour Coded Seed Tray Shelving

+ £365

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

Qty 1

£15 off

1 Tier Staging Colour Matched

+ £74

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)

Qty 1

Janssens Integrated Colour Matched Shelving

+ £55

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

Qty 1

£23 off

2 Tier Staging Colour Matched

+ £96

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)

Qty 1

£10 off

Top Tier Staging Extension Colour Matched

+ £49

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

Qty 1

Janssens Silver Integrated Staging

+ £80

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

Qty 1

Additional Double Hinged Door

+ £950

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

Qty 1

Staging and Doors information

Janssens Colour Coded Full Length Integrated Staging - £135.00

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

Janssens Colour Coded Seed Tray Shelving - £365.00

Add the Colour Coded 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

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

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

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

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

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

Additional Double Hinged Door - £950.00

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

Add Extras?

Hygrometer

+ £17

This Hygrometer will measure the humidity levels inside your greenhouse.

Soil Thermometer

+ £29

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

Max/Min Thermometer

+ £23

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

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

Qty 1

Extras information

Hygrometer - £17.00

This Hygrometer will measure the humidity levels inside your greenhouse.

Soil Thermometer - £29.00

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

Max/Min Thermometer - £23.00

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

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

Was £27250.00

£27,100

SAVE £150

Use Code XMAS50 £50 OFF

🚚

FREE* delivery within 16 Weeks

* Some areas may incur a delivery charge.

Limited New Season Stock

£27100

Delivery 4-16 weeks ⛟

10 Year Warranty
Free UK Delivery
Expert Installation Available

Need Help Choosing?

📞 0800 098 8877

CALL US FOR A GREAT DEAL

Description
Features
Delivery
Dimensions

The 17ft x 39ft Janssens Gigant Victorian 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 vegetables year round.

The Gigant Greenhouse comes with a choice of Green, White or Black Powder Coating meaning that this greenhouse will also make a stylish statement in your garden.

As Janssens' largest greenhouse range, available up to 6 meters wide and 18 meters long in 2ft increments, it offers vast growing space for year-round cultivation, while its striking industrial aesthetic and high ridge height make it equally suited to entertaining, exhibitions, or as a pool canopy.

The robust frame of the Janssens Gigant Greenhouses are supported by a self-supporting bottom profile with rubber glazing gaskets, internal condensation gutter, and stainless steel fasteners for years of maintenance-free use. Whether gardening or pursuing other passions, the Gigant provides impressive space and versatility to make your garden dreams a reality.

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 11950mm Dimensions (17ft 5" x 39ft 2")
2m High Eaves
Aluminium Frame with Tubular and Box Section for Superior Strength.
Green, White or Black Powder Coated Frame.
Box Section Base Plinth.
Double Hinged Dampened Doors - Outward Opening
4mm Full Length Toughened Safety Glass
Rubber Glazing Gasket Strips (no fiddly clips)
12 x Roof Vents
6 x 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: If selected, Installation will be carried out 1-8 weeks after the delivery of your Greenhouse. The Installation Team will contact you directly to book in your installation.Our installation service requires a level concrete, slabbed, or decked area to the minimum size stated on the website. Failure to provide a suitable base area may result in you being charged for the failed installation. If you require staging or shelving assembly, you can arrange it directly with the installation team.

Greenhouse Dimensions

A: Greenhouse width

5320mm (17′ 5″)

B: Greenhouse depth

11950mm (39′ 2″)

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 11950mm (39′ 2″)

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 â€“ your thriving garden.

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

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!

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,

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

Effortless Assembly at Your Fingertips

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

Detailed step-by-step manual
Comprehensive assembly video

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 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.

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.

Greenhouse Buyers Guide 2025

This comprehensive 2025 guide helps you choose the perfect greenhouse by exploring crucial factors from size and materials to optimal location and essential accessories.

Make an informed decision by understanding how to assess your needs, compare material pros and cons, and ensure proper ventilation and positioning for a thriving greenhouse.

How To Build A Paving Slab Base For A Greenhouse - Complete Step-by-step Guide

Discover how to build a sturdy paving slab base for your greenhouse with our comprehensive step-by-step guide. From selecting the right location to preparing the ground and laying the slabs, we cover everything you need to know to ensure a solid foundation for your greenhouse.

How To Build A Concrete Base For A Greenhouse - A Simple DIY Guide

Learn how to build a durable concrete base for your greenhouse with our easy-to-follow DIY guide. We cover everything from choosing the right location and preparing the ground to mixing and pouring the concrete, ensuring a solid foundation for your greenhouse.

How to Prepare the Ground for a Greenhouse Base

A solid base is the backbone of any greenhouse. You might think skipping this step saves time, but trust me?I've seen plenty of greenhouses fail because of poor foundations. A dodgy base causes more headaches than you'd believe.

What happens with a bad base? Glass cracks. Doors jam. The structure twists. Water pools where it shouldn't. And fixing these problems costs way more than doing it right first time.

Placing your greenhouse in the right spot makes all the difference between thriving plants and disappointing results. As a greenhouse specialist who's spent 15 years helping UK gardeners optimise their growing spaces, I've seen first-hand how position affects everything from temperature regulation to plant health.

Let me share what actually works in our unique British climate. The greenhouse position might seem like a minor detail, but it's one of those things that can make or break your growing success. I made this mistake myself when I first started - my poorly positioned greenhouse meant I was fighting an uphill battle with inadequate light and temperature fluctuations.