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17x29 Janssens Gigant Hobby Greenhouse

  • 17ft 5" wide x 29ft 6" deep
  • 4mm Full Length Toughened Safety Glass
  • Extra Strong Aluminium Frame
  • Choice of Powder Coated Finishes
  • Double Hinged Door
  • 8 x Roof Vents
  • 4 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 Size Diagram

Greenhouse Dimensions

A: Greenhouse width

5320mm (17′ 5″)

B: Greenhouse depth

9000mm (29′ 6″)

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:

5320mm (17′ 5″) x 9000mm (29′ 6″)

Customise your Greenhouse

More Sizes:

Select your Colour:

Add Staging?

Qty 1
Janssens Colour Matched Integrated Shelving
+ £195

Add the Silver 458cm long x 23cm wide integrated shelving to your greenhouse to help retain your floor space

Qty 1
Qty 1
Janssens Colour Matched integrated Staging
+ £110

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

Qty 1
Janssens Seed Tray Shelving
+ £420

Add the Silver 605cm long Seed Tray Shelving to your greenhouse to help retain your floor space

Qty 1
£10 off
£10 off
1 Tier Staging Silver
+ £69

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

Qty 1
£11 off
£11 off
2 Tier Staging Silver
+ £88

This 2 Tier Vitavia silver 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
£10 off
Top Tier Staging Extension Silver
+ £49

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

Qty 1

Staging information

Janssens Silver Integrated Shelving - £149.00
Janssens Silver Integrated Shelving

Add the Silver 458cm long x 23cm Wide integrated shelving to the side of your greenhouse to help retain your floor space


Janssens Colour Matched Integrated Shelving - £195.00
Janssens Colour Matched Integrated Shelving

Add the Silver 458cm long x 23cm wide integrated shelving to your greenhouse to help retain your floor space


Janssens Silver Integrated Staging - £95.00
Janssens Silver Integrated Staging

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


Janssens Colour Matched integrated Staging - £110.00
Janssens Colour Matched integrated Staging

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


Janssens Seed Tray Shelving - £420.00
Janssens Seed Tray Shelving

Add the Silver 605cm long Seed Tray Shelving to your greenhouse to help retain your floor space


1 Tier Staging Silver - £69.00
1 Tier Staging Silver

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


2 Tier Staging Silver - £88.00
2 Tier Staging Silver

This 2 Tier Vitavia silver 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 Silver - £49.00
Top Tier Staging Extension Silver

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


Add Ventilation and Shading?

Qty 1
Louvre Vent
+ £165

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

Qty 1

Ventilation and Shading information

Auto Roof Vent Opener - £75.00
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.


Louvre Vent - £165.00
Louvre Vent

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


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
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


Add Ventilation and Shading?

Qty 1
Louvre Vent
+ £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
+ £99

Add roof ventilation to your greenhouse to help moderate the temperature

Qty 1
Janssens Side Vent
+ £150

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

Qty 1

Ventilation and Shading information

Auto Roof Vent Opener - £75.00
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.


Louvre Vent - £165.00
Louvre Vent

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


Additional Roof Vent - £99.00
Additional Roof Vent

Add roof ventilation to your greenhouse to help moderate the temperature


Janssens Side Vent - £150.00
Janssens Side Vent

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


The 17ft x 29ft Janssens Gigant Hobby Greenhouse is an architectural masterpiece and the strongest aluminium greenhouse on the market, featuring full box-section construction with 4mm toughened glass to withstand the harshest UK weather.

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!
  • 5320mm x 9000mm Dimensions (17ft 5" x 29ft 6")
  • 2m High Eaves
  • Aluminium Frame with Tubular and Box Section for Superior Strength.
  • Box Section Base Plinth.
  • Double Hinged Dampened Doors - Outward Opening
  • 4mm Full Length Toughened Safety Glass
  • Rubber Glazing Gasket Strips (no fiddly clips)
  • 8 x Roof Vents
  • 4 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 Size Diagram

Greenhouse Dimensions

A: Greenhouse width

5320mm (17′ 5″)

B: Greenhouse depth

9000mm (29′ 6″)

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:

5320mm (17′ 5″) x 9000mm (29′ 6″)

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!

Toughened Safety Glass
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.