12×28 Greenhouse Kit is the Solution for Your Year-round Gardening Needs

The Summit 12×28 Greenhouse Kit is designed to provide an exceptional growing environment, combining strength, space, and insulation in a beautiful barn-style greenhouse. With its heavy-duty aluminum frame and 10mm twin-wall polycarbonate panels, the Summit greenhouse is built to last in any climate. Its barn shape offers plenty of room for plants while adding an elegant touch to any garden.

BENEFITS

Durable Build for Tough Conditions: Constructed from a sturdy 1.6mm profile aluminum frame, this greenhouse is built to handle harsh weather, ensuring that your plants stay safe. Its rugged design makes it highly reliable, allowing you to enjoy gardening all year long, regardless of the climate.

Keeps Your Plants Warm All Year: The 10mm twin-wall polycarbonate panels offer excellent insulation, with an R-value of 1.89* and a heat loss U-value of 0.53, helping to retain warmth and reduce energy costs. This makes the Summit an ideal greenhouse for gardeners looking to extend their growing season into cooler months.

Easy to Use and Access: With sliding double doors that move smoothly and don’t get stuck, getting in and out of the greenhouse is hassle-free. Made with durable materials, the doors also have lockable handles for security, and fourteen roof windows let fresh air circulate to keep your plants healthy.

Comes with Extra Features: Equipped with rain gutters, a drain kit, a snow load kit, and anchors, this greenhouse is ready for any kind of weather. These features make it an ideal choice for beginners and experienced gardeners alike who want a dependable greenhouse.

The Summit 12×28 Greenhouse Kit combines durability, warmth, and ease of use, giving you a large, protected space for growing plants throughout the year.

SPECIFICATIONS

Frame	Heavy Duty Aluminum
Color	Powder-Coated Green
Panels	10mm Twin-wall UV-protected Polycarbonate
Doors	Bind-resistant Sliding Double doors
Latch	Magnetic latch doors with key lock
Reinforcement	Cross-roof truss and cross-corner bracing
Hardware	Stainless steel nuts and bolts
Rain Gutters	Yes
Ventilation	14 Roof vents with adjustable manual openers/latches
Wind Rating	Withstands winds up to 76 mph*
Snow Rating	Maximum snow load of 25lbs./ft² of snow*

DIMENSIONS

Actual Size: 12' W x 28' L x 9.25' H
Door Size: 41.5" W x 85" H

GRANDIO GREENHOUSE MATERIALS VS OTHER BRANDS

WHAT'S INCLUDED IN THE PACKAGE?

Basic Kit Includes:

10mm Twin-Wall Panels
(14) Roof Windows
Rain Gutters
Drain Kit
Extreme Snow Load Kit
Flat Mount Anchor Kit

Optional Premium Kit Includes:

10mm Twin-Wall Panels
(14) Roof Window
Rain Gutters
Base Kit
Drain Kit
Extreme Snow Load Kit
Flat Mount Anchor Kit
(14) Auto Roof Vent Openers
(2) Pack of 10 Plant Hangers
(1) Trellis Kit
(1) Drip Kit
(2) 8 oz. Brillianize Cleaner

ASSEMBLY VIDEO

Optional Accessories

	Drain Kit – Downspout for Grandio Greenhouse Gutter Systems, designed for installation at each of the four corners of the greenhouse. It’s made to be installed directly into the aluminum frame and gutter of the greenhouse. The easy-to-install downspout drain kit includes (4) 20mm black pipes, (4) gutter attachment gaskets, and (4) side wall brackets with screws. One kit has everything needed to add downspouts to a Grandio Greenhouse.
	Automatic Roof Vent Opener – Automatically opens and closes the roof vent window based on temperature changes. The opener contains a metal cylinder with a mineral that expands when heated, pushing a piston to open the vent. When the temperature cools, the mineral contracts, and a spring closes the vent, resetting the piston. The vent opens and closes gradually, allowing the right amount of airflow for cooling.
	Auto Louver Window Opener – Automatically opens and closes the louver window as the temperature changes. The opener has a metal cylinder with a mineral that expands when heated, pushing a piston to open the vent. As the temperature cools, the mineral contracts, and a spring closes the vent and resets the piston. The vent opens and closes gradually, providing just the right amount of airflow for cooling. This Auto Louver Opener attaches to the left side of your louver window.
	Louver Window – add more ventilation to your greenhouse. Louver window frame comes powder coated in green, with 6mm twin wall polycarbonate panels.
	The Drip Irrigation Watering Kit – is a water-efficient system designed for shrubs, trees, flowers, and bushes, covering up to 150 square feet with easy expandability. It's a DIY-friendly installation with no gluing required, using high-quality UV-resistant materials. The kit includes 24 pressure-compensating drippers (20 at 1 GPH, 2 at 2 GPH, and 2 at 4 GPH) for consistent water delivery to plant roots. A backflow preventer ensures water safety by preventing siphoning into the main supply.
	Moisture Control Kit – featuring Anti Dust Tape and Waterproof All-Weather Silicone Caulk, protects your Grandio Greenhouse from insects, dirt, mold, and algae. The tape's 45-micron filters allow condensation to escape while preventing algae and mold growth with a fungicidal coating. Combined with the silicone caulk, this kit ensures long-lasting protection and maintains the greenhouse's pristine condition.
	Shade Net – are essential for regulating greenhouse temperatures, especially during sunny spring, autumn, and summer days. Designed to reduce intense sunlight by 50%, they help keep your greenhouse cooler and prevent overheating.
	Plant Hangers – These versatile plastic hangers are designed for greenhouse use, supporting shade cloths, hanging baskets with quarter-inch hooks, and stringing taller plants or vines. Easy to install, they simply twist into the roof rafter channels.