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Grandio Greenhouses

Grandio Summit 12x8 Greenhouse Kit

SKU SUMMIT-128-WOOD
$3,899.00
$3,899.00

Estimated shipping time

You can typically expect your items to arrive within 4–7 business days, depending on your location and product availability.

What is your Return Policy?

At Northgrid Supply, we want every customer to shop with confidence. If something doesn’t go as planned, we’ve made returns and refunds simple and fair. Here’s how it works:

1. Return Window

You can request a return within 30 days of receiving your order. Unfortunately, we’re unable to accept returns after that time frame.

2. Who Pays for Return Shipping?

  • If your item arrives damaged, defective, or incorrect, we’ll cover the return shipping cost.
  • If you’re returning an item because you changed your mind, you’ll be responsible for return shipping fees.

3. Damaged or Defective Items

Received something broken or not working properly? Contact us within 30 days. We’ll provide a prepaid return label and once the item is returned and inspected, we’ll issue either a full refund or a replacement—including any original shipping costs.

4. Changed Your Mind?

If you no longer want the item, you can return it within 30 days—as long as it's unused, in its original packaging, and in resellable condition. You’ll need to handle the return shipping, and once we receive and inspect it, we’ll refund the product cost (excluding shipping).

5. Refund Processing

Once we receive and approve your return, we’ll send a confirmation email and issue a refund to your original payment method within 7 business days. Please allow additional time for banks or credit card companies to process and reflect the refund.

If it’s been over 10 business days since your refund was approved and you still don’t see it, contact us at support@northgridsupply.com and we’ll look into it immediately.

6. Restocking Fees

Change-of-mind returns are subject to a 25% restocking fee. Damaged, defective, or incorrect items are not charged a restocking fee.

This 12 ft. x 8 ft. greenhouse provides a wide, barn-style growing structure with a 9 ft. 3 in. peak height. Its powder-coated aluminum frame incorporates cross-roof trusses and cross-corner bracing, while 10 mm twin-wall polycarbonate panels enclose the growing space.

The greenhouse includes 4 roof vents, built-in rain gutters, a snow-load kit, and a bind-resistant double sliding door with a magnetic latch and key lock. Wood, concrete, and dirt anchoring configurations are selectable to accommodate different installation surfaces.

Key Features

  • Reinforced Aluminum Frame: The heavy-duty aluminum frame uses 1.2 mm members with 1.5 mm reinforced areas, cross-roof trusses, and cross-corner bracing.
  • Twin-Wall Panels: The greenhouse uses 10 mm twin-wall polycarbonate panels.
  • Tall Barn-Style Design: The 9 ft. 3 in. peak height provides substantial vertical space within the 12 ft. x 8 ft. structure.
  • Double Sliding Door: The bind-resistant double sliding door measures 3 ft. 6 in. x 7 ft. 1.5 in.
  • Lockable Entry: A magnetic latch with key lock secures the sliding door.
  • Roof Ventilation: 4 roof vents are included for ventilation.
  • Rainwater Management: Built-in rain gutters are incorporated into the greenhouse.
  • Structural Weather Ratings: The greenhouse has a maximum snow-load rating of 25 lbs./ft² of snow and withstands winds up to 76 mph when properly anchored.
  • Expandable Design: The structure accepts 4 ft. or 8 ft. extension lengths.
  • Optional Rear Entry: An optional back-door transformation kit is available separately.
Heavy-duty construction icon

Heavy-Duty Construction & Rust Proof

Year-round insulation icon

Exceptional Year-Round Insulation

Greenhouse peak height icon

Impressive 9.25' Peak Height Maximum Headroom & Vertical Space

Ventilation icon

Advanced Ventilation & All-Weather Performance

Wide lockable double sliding doors icon

Wide, Lockable, Double Sliding Doors

Premium Upgrade

  • Roof Vent Auto Openers: 4
  • Plant Hangers: 10
  • Anti-Static Panel Cleaner: 1 Brillianize Anti-Static Panel Cleaner
  • Trellising Kit: 1
  • Drip Irrigation Kit: 1

Current Upgrade Price: $0.00

Crossed-Out Upgrade Price: $519.00

Specifications

  • Height: 9 ft. 3 in.
  • Width: 12 ft.
  • Length: 8 ft.
  • Frame: 1.2 mm heavy-duty aluminum with 1.5 mm reinforced areas
  • Reinforcement: Cross-roof trusses and cross-corner bracing
  • Frame Color: Powder-coated green
  • Door Type: Bind-resistant double sliding door
  • Latch: Magnetic latch with key lock
  • Door Dimensions: 3 ft. 6 in. x 7 ft. 1.5 in.
  • Polycarbonate Panel Thickness: 10 mm
  • Number of Roof Vents: 4
  • Rain Gutters: Built-in
  • Steel Base Kit: Sold separately; added with the Dirt anchor configuration
  • Snow-Load Kit: Included
  • Optional Back-Door Kit: Yes
  • Extendable: Yes, 4 ft. or 8 ft. length
  • Anchor Options: Wood, Concrete, Dirt (with added Steel Base Kit)
  • Snow Rating: Maximum snow load of 25 lbs./ft² of snow
  • Wind Rating: Withstands winds up to 76 mph when properly anchored

Size Guide

  • Product Size: 12 ft. wide x 8 ft. long x 9 ft. 3 in. high
  • Door Size: 3 ft. 6 in. wide x 7 ft. 1.5 in. high

Compatibility

Compatible With: 4 ft. and 8 ft. Summit extension lengths and the optional back-door transformation kit.

Included

  • Heavy-duty powder-coated aluminum frame
  • 10 mm twin-wall polycarbonate panels
  • 4 roof vents
  • Built-in rain gutters
  • Snow-load kit
  • Cross-roof trusses
  • Cross-corner bracing
  • Bind-resistant double sliding door
  • Magnetic latch with key lock
  • Flat-mount base/anchor kit for the selected Wood or Concrete installation configuration
  • Stainless-steel hardware
  • Required assembly tools
  • 4 roof-vent auto openers with the Premium Upgrade
  • 10 plant hangers with the Premium Upgrade
  • 1 Brillianize Anti-Static Panel Cleaner with the Premium Upgrade
  • 1 trellising kit with the Premium Upgrade
  • 1 drip-irrigation kit with the Premium Upgrade

Foundation & Anchoring Solutions

  • Wood Installation: Select the Wood anchor configuration for decks, wooden platforms, or timber bases. The Wood Anchoring Kit secures the greenhouse to the wood foundation.
  • Concrete Installation: Select the Concrete anchor configuration for pavement, concrete slabs, or other hard surfaces. The Concrete Anchoring Kit secures the greenhouse to the hard surface.
  • Ground or Dirt Installation: Select the Dirt anchor configuration for dirt or earth installations. This configuration adds the required heavy-duty powder-coated steel base kit for $499. The base provides an additional 3 in. of headroom.

Warranty

Warranty: Lifetime warranty on the aluminum frame; 15-year warranty on the polycarbonate panels.

Product Support

Printable Spec

Frequently Asked Questions

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  • SATISFACTION GUARANTEED 

    If your order arrives defective or fails to

    function properly, you will receive a full 100% refund!

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