Grandio Summit Greenhouse 12x16

The Grandio Summit 12×16 Greenhouse is a large, barn-style structure built for serious gardeners and four-season growers. With 192 square feet of interior space, nearly 8'2" of peak height, and ultra-insulating 10mm twin-wall polycarbonate panels, this greenhouse is ready to handle tough weather—and tough growing demands.

Featuring a 1.6mm heavy-duty aluminum frame, reinforced overhead sliding doors, and brass-fitted nylon wheels, the Summit 12×16 offers the ultimate blend of strength, insulation, and ease of use. Whether you're overwintering ornamentals, starting crops, or expanding your home growing operation, this greenhouse brings commercial-level durability to your backyard.

NEW ORDERS TO SHIP MID-LATE MAY

Key Benefits

• 10mm twin-wall UV-protected polycarbonate panels (R-Value: 1.89 / U-Value: 0.53)

• Heavy-duty 1.6mm aluminum frame resists warping, rust, and bending

• Barn-style roof increases grow height and sheds snow efficiently

• Re-engineered overhead sliding doors glide smoothly and won’t jam

• Brass-fitted nylon wheels reduce wear and extend door longevity

• Lockable door handles and included keys for added security

• Built-in roof vents support natural ventilation and temperature regulation

• DIY-friendly kit with pre-drilled components and clear instructions

• Backed by a lifetime frame warranty and 10-year panel guarantee

Grandio Summit 12x16 Greenhouse for High-Volume, All-Season Growing

Engineered for cold winters, windy regions, and ambitious growers, the Summit’s twin-wall polycarbonate panels help maintain stable temperatures while filtering harsh UV rays. The wide 12' by 16' layout accommodates multi-tier setups, seed trays, benches, and tall plants with ease—while the barn-shaped frame delivers elegant form with highly functional structure.

Ideal Applications

• Year-round residential or homestead food production

• Overwintering citrus, palms, and tropical plants

• Seed propagation with bench systems or trays

• Vertical gardening and tall plant structures

• Educational or hobby greenhouses needing generous space

Grandio Summit 12x16 Greenhouse Kit with Durable Brass-Fitted Sliding Doors

Every detail of the Summit is designed for performance and longevity. The re-engineered doors glide on an overhead track to avoid jamming and debris buildup. Each wheel bolt is machined from solid brass and fitted with high-grade nylon wheels for smooth, consistent use—even in extreme weather. Lockable handles come standard, adding peace of mind to your greenhouse investment.

What's the Difference Between the Basic and Premium Kit?

Both the Basic and Premium kits are equipped with Grandio’s ultra-insulated 10mm twin-wall polycarbonate panels, an extreme snow load kit, integrated rain gutters, a drainage system, a flat mount anchor kit, and (8) roof windows—making them ready for reliable, all-season greenhouse performance.

The Premium Kit expands your capabilities with valuable upgrades designed for efficiency and ease of use:

• (8) Automatic Roof Window Openers – Automatically regulate airflow and temperature

• (2) Packs of 10 Plant Hangers – Add vertical versatility for baskets, lighting, or trellised crops

• (1) Trellis Kit – Train climbing plants for healthier, space-efficient growth

• (1) Drip Irrigation Kit – Keeps plants consistently hydrated with minimal effort

• (2) 8 oz. Bottles of Brillianize Cleaner – Maintain panel clarity and protect against UV degradation

If you're looking for a fully equipped solution right out of the box, the Premium Kit offers the most complete and convenient growing experience.

Maintenance Tips

• Clean panels seasonally with mild soap and water for maximum light diffusion

• Keep the sliding door track clear of leaves, dirt, and snow buildup

• Lubricate brass fittings and nylon wheels once a year

• Inspect and tighten fasteners after storms or seasonal shifts

• Anchor the structure to a level wood or concrete base for peak wind resistance

Choose the best foundation for your greenhouse with our customizable base kits:

🔹 Optional Steel Base Kit – Ideal for windy or extreme environments, this heavy-duty steel base adds extra strength, stability, and 3 inches of headroom. Powder-coated to resist rust and decay, it includes anchoring options for earth/soil, concrete slabs, or wooden decks.

🔹 Included Flat Mount Base Kit – Perfect for controlled environments like fenced-in yards or patios. This base secures to concrete slabs or wooden decks, providing a stable foundation for your greenhouse. If installing over soil, the Steel Base Kit is required for optimal support.

Reach the Summit of Strength, Style, and All-Season Growing

The Grandio Summit 12×16 Greenhouse Kit gives you the insulation, space, and security to grow better all year. Designed to handle the most demanding environments, this greenhouse is your go-to choice for long-term performance and maximum productivity.

Premium Kit Includes:

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

Specifications

• Height: 9.5′
• Width: 12′
• Length: 16′
• Frame: Heavy duty aluminum.
• Wind Rating: Withstands winds up to 76 mph*
• Snow Rating: Maximum snow load of 25lbs./ft² of snow*
• Color: Powder coated green.
• Panels: 10mm twin-wall UV protected polycarbonate.
• Door Size: 41.5″ W x 85″ H
• Doors: Bind-resistant sliding double-doors.
• Latch: Magnetic latch doors with key lock.
• Reinforcement: Cross-roof truss and cross corner bracing.
• Tools: Included
• Hardware: Stainless steel nuts and bolts.
• Gutters: Built-in rain gutters.
• Ventilation: (8) roof vent with adjustable manual openers/latches

User Manual/ Assembly 

FAQ

You have questions, no problem, we have answers.

How easy is the Grandio to assemble? Very easy. We’ve designed and perfected the assembly process with you in mind. We provide the tools and a step-by-step assembly manual and video and if you have any problems you can call us at 1-844 873-5764.

Is a building permit required? You may not need a permit for your Grandio, but it is always a good idea check before you get started. We recommend you check local ordinances and requirements before setting up your greenhouse.

Is it strong enough for windy or heavy snow locations? Definitely. Grandio’s are all designed to withstand the most hostile environments with a wind rating of 76 MPH and snow load rating of 25lbs./ft² of snow. We offer additional roof and eave supports to increase the strength and durability of the greenhouse frame for the Element Greenhouses. Just follow the included directions for securing your greenhouse and you’ll enjoy many years of growing with your Grandio.

I live in the hot southwest will Grandio Greenhouses work for me? For people who live in high temperature areas of the country like Arizona, Texas, California, Nevada, or New Mexico we recommend our aluminum shade net. The aluminum shade net reflects the sun on the hottest days to help your greenhouse keep it’s cool.

How do the automatic roof vent openers work? The opener has a metal cylinder containing a mineral which expands when heated. This pushes a piston that opens the vent. As the temperature cools, the mineral shrinks and a spring closes the vent and resets the piston. The opening and closing of the vent is gradual allowing just the right amount of air flow for cooling. No electricity needed!

How large is the roof vent opening? The vent opening is 18-3/4″ width by 22-3/4” length.

What is the difference in polycarbonate thicknesses? Polycarbonate is available in several different thicknesses and normally comes in single, double, and triple walled sheets that can vary in thickness from 1mm to 10mm. A good rule to remember is that the thicker the panel the better insulation you’ll have for your greenhouse.

Can these greenhouse be mounted to a concrete pad? The Grandio comes standard with a base that is meant to anchor it in the soil with concrete footers or a duckbill anchor kit. However, it can be mounted to a concrete pad with additional tools and hardware. For more information please refer to our online manual or give us a call 1-844 873-5764 to discuss options.

Can’t wait for your Grandio? Here’s what to expect.

How many boxes will I receive?
Your new Grandio ships in 2 or more manageable-sized boxes (the exact number of boxes depends on the size of your greenhouse).

How is it shipped?
Grandio Greenhouses are generally shipped via UPS Ground.

Can I buy a Grandio if I live outside the USA?
Currently we can only ship orders to the USA.

How long will my order take to get to me?

• West: 2-4 business days

• Northwest: 1-3 business days

• Southwest: 3-5 business days

• Midwest: 4-6 business days

• East: 5-7 business days

Note: These are estimates and business days are the time your items are in-transit only and do not include order processing time. Inclement weather and unforeseen carrier or transportation emergencies may delay your delivery.

Videos

Warranty

• Frame: Lifetime limited warranty

• Panels: 10-year limited warranty

• Doors & Hardware: 1-year warranty