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Premium Insulated Greenhouse for Cold Climates and All-Season Growers
Designed for rugged environments and serious gardeners, the Grandio Summit 12×8 Greenhouse Kit combines barn-style beauty with heavy-duty functionality. From its secure sliding doors to its 10mm twin-wall polycarbonate insulation, this greenhouse is made to handle snow, wind, and everything in between—while giving you the bright, spacious interior you need for year-round success.
Whether you’re starting seeds, protecting citrus trees, or growing winter vegetables, the Summit offers a professional-grade solution with refined usability.
✅ Quick-Glance Benefits
🏡 Barn-Style Elegance Tall, iconic roof design maximizes space and sheds snow with ease |
🔐 Secure Sliding Doors Overhead-mounted with brass hardware and a locking handle |
❄️ Four-Season Protection 10mm polycarbonate panels offer superior insulation and UV resistance |
🔩 Reinforced Aluminum Frame 1.6mm commercial-grade aluminum resists bending, warping, and rust |
🌬️ Built-In Ventilation (4) roof windows regulate airflow and reduce interior humidity |
What’s Included
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10mm Twin-Wall Polycarbonate Panels
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1.6mm Powder-Coated Aluminum Frame
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Overhead-Mounted Double Sliding Doors with Lock & Key
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(4) Roof Windows
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Integrated Rain Gutter & Drainage Kit
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Extreme Snow Load Reinforcement Kit
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Flat Mount Anchor Kit
Use It For
✔️ Cold-climate seed starting
✔️ Overwintering ornamentals and citrus
✔️ Year-round vegetable and herb gardening
✔️ Backyard greenhouse teaching or display
🔍 Standout Features
🌞 Maximum Light Diffusion Even lighting inside while blocking UV damage to sensitive plants |
🔐 Lockable Entryway Heavy-duty handles and locking steel hardware provide added security |
🧼 Easy-to-Clean Panels Resist yellowing, cracking, and are simple to wipe clean seasonally |
🛠️ DIY Assembly Kit Pre-drilled parts with illustrated step-by-step instructions included |
What’s the Difference Between the Premium and Basic Kit?
Both Kits Include:
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10mm Twin-Wall Polycarbonate Panels
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(4) Manual Roof Windows
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Integrated Rain Gutter & Drain Kit
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Extreme Snow Load Reinforcement Kit
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Flat Mount Anchor Kit
Premium Kit Adds:
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(4) Automatic Roof Vent Openers
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(1) Pack of 10 Plant Hangers
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(1) Drip Irrigation Kit
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(1) Trellis Kit
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(1) 8 oz. Bottle of Brillianize Panel Cleaner
The Premium Kit adds hands-free climate control and plant support tools to help you grow efficiently with less hands-on work.
Secure and Stable Foundation Options
Optional Steel Base Kit
Powder-coated for rust resistance and structural strength. Adds 3" of interior headroom and includes anchoring for soil, concrete, or wood. Best for exposed or high-wind areas.
Included Flat Mount Base Kit
Ideal for decks, patios, or concrete slabs. Anchors securely to flat surfaces. If installing over soil, the Steel Base Kit is strongly recommended for stability.
Elevate Your Growing Game
From cold winters to bright summer days, the Grandio Summit 12×8 Greenhouse Kit is built for confident gardeners who want professional-quality performance with elevated design. Add to cart today and experience the difference season after season.
Buy with confidence – we’re an Authorized Grandio® Greenhouse Dealer. Every purchase includes full manufacturer warranty + exclusive support. [Learn more →] Grandio Authorized Dealer Page
- Height: 9.5′
- Width: 12′
- Length: 8′
- 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: (4) roof vent with adjustable manual openers/latches.
This is your resource for finding complete assembly instructions for all Grandio Summit Greenhouses. You can download the instructions in PDF format or you can view the assembly video. We’ve provided everything you need to get started with your new Grandio greenhouse. Have questions? Give us a call 1-866-448-8231.
Grandio Summit Greenhouse Assembly Manuals
» Download: Grandio Summit Manual 1 – Base Kit Assembly Instructions and Installation
» Download: Grandio Summit Manual 2 – Summit Greenhouse Assembly Instructions
» Download: Grandio Summit Manual 3 – Itemized Parts List, Graphics, Descriptions and Quantities
Grandio Summit Greenhouse Anchoring Kit Manuals
» Download: Grandio Summit Manual 1 – Flat and Earth Base Kit Assembly with Earth Anchoring Kit
» Download: Grandio Summit Wood Anchoring Kit Supplement Manual
» Download: Grandio Summit Concrete Anchoring Kit Supplement Manual
Note: In order to read the manuals, you need the Adobe Acrobat PDF reader.
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?
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West: 2-4 business days
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Northwest: 1-3 business days
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Southwest: 3-5 business days
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Midwest: 4-6 business days
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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.
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Frame: Lifetime limited warranty
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Panels: 10-year limited warranty
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Doors & Hardware: 1-year warranty
Who We Are
At Garden GrowShop, we're not a faceless online retailer. We're a small, family-run business with real roots in the growing community. Every product we carry has been carefully chosen to meet the needs of both home growers and commercial operators — because we’ve walked in your shoes.
Personal, Knowledgeable Support
When you reach out to us, you’re not getting a canned reply or being passed between departments. You're talking to someone who actually knows the products, understands your challenges, and is here to help you succeed.
Transparent Pricing — No Gimmicks
We believe in fair, honest pricing. No inflated markups, no bait-and-switch tactics. If you ever find a better price on the same item, let us know — we’ll match it without the hassle.
Fast, Dependable Shipping
We ship directly from warehouses across the U.S. to get your order to you quickly and reliably. No inflated delivery timelines, and no surprise shipping fees — just smooth, on-time delivery you can count on.
A Partnership, Not a Transaction
Our customers stick with us because we treat them like partners. Whether you're outfitting a small indoor setup or managing a large-scale operation, we’re here to grow with you — not just sell you equipment.
Our Commitment
If something goes wrong, we don’t pass the buck. We work with you directly to make it right. That’s how we’ve built our business, and that’s how we plan to keep it.
Shipping Policy
Free Shipping Within the Continental U.S.
We offer free shipping on all orders over $200 shipped to addresses within the continental United States. Orders under $200 will have shipping calculated at checkout. There are no hidden fees or handling charges. The price you see at checkout is the final price you pay.
Order Processing
Orders are typically processed within 1–2 business days (Monday–Friday). If an item is temporarily backordered or delayed, we’ll notify you by email with an updated shipping estimate.
Shipping Confirmation & Tracking
Once your order has shipped, we’ll email you a shipping confirmation that includes tracking information. You can use this to monitor the delivery status of your package in real time.
Where Orders Ship From
We partner with trusted suppliers and manufacturers who maintain warehouse locations throughout the United States. Orders are typically shipped from the facility closest to your delivery address to ensure faster transit times and greater efficiency. Some orders may ship in multiple packages depending on item availability and warehouse location.
Estimated Delivery Time
Most orders arrive within 3–7 business days of shipping, depending on your location and the item’s warehouse origin. Freight items and oversized packages may take additional time.
Shipping Carriers
We use trusted carriers such as FedEx, UPS, USPS, and professional freight delivery services for large or heavy items. Depending on the size of your order, it may arrive in multiple packages or from multiple warehouses.
Delivery and Moving Disclaimer
Please note: We do not offer moving or installation services. For freight shipments or large items, carriers are only responsible for curbside delivery. Drivers are not required to move items inside your home, up stairs, or to specific locations. We strongly recommend having assistance available at the time of delivery for heavy or bulky shipments.
Address Accuracy & Order Changes
Please ensure your shipping address is correct at the time of checkout. Once an order has shipped, we are unable to change the delivery address or reroute the shipment. If you need to make changes to your order, contact us immediately after placing it.
Damaged or Lost Shipments
If your order arrives damaged or appears to be lost in transit, contact us within 48 hours of delivery (or expected delivery). We will work with the carrier to resolve the issue as quickly as possible.
Shipping Restrictions
We currently ship only to addresses within the continental United States. We do not ship to Alaska, Hawaii, U.S. territories, or international destinations.
Questions?
If you have questions about your order, delivery, or shipping process, feel free to reach out to us through our Contact Us page or via email (sales@gardengrowshop.com ). We’re here to help.
Start of Returns section
Easy Returns, No Surprises
At Garden GrowShop, we stand behind the quality of every product we carry. But we also understand that sometimes things just don’t work out — and that’s okay. If you change your mind or the item isn’t quite what you expected, we’ve got you covered.
30-Day Return Guarantee
You have 30 days from the date of delivery to request a return for any reason. To start a return, simply email us at sales@gardengrowshop.com with your order number and we’ll walk you through the process.
Here’s what to expect:
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You’ll receive clear return instructions from our team.
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Once your item is received and inspected, we’ll issue a refund to your original payment method.
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Items must be returned in “like new” condition, with all original packaging and accessories.
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Return shipping costs are the responsibility of the customer.
“Like new” means no visible wear, damage, or missing parts. Items showing signs of use or misuse may not qualify for a refund.
Damaged or Defective Orders
If your order arrives damaged or defective, don’t worry — we’ll take care of it.
Here’s what to do:
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Note any damage with the delivery driver when signing for the package.
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Email photos and a description of the issue to sales@gardengrowshop.com on the same day you receive it.
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We’ll cover the cost of return shipping and make sure a replacement is sent out quickly.
Please keep all original packaging in case a return is needed. This helps speed up the process and ensures a smooth resolution.
Order Cancellations
If you need to cancel your order, please contact us as soon as possible at sales@gardengrowshop.com or by phone.
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Cancellations before shipment receive a full refund.
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Cancellations after shipment will follow our standard return policy and may be subject to return shipping costs.
Important Return Notes:
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Certain products may have brand-specific return restrictions, which will be noted on the product page.
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Products purchased for temporary or single-use purposes (e.g. trade shows, promotional events) are not eligible for return.
We’re Here to Help
Our goal is to make returns and exchanges as easy as possible — with no stress and no surprises. If you’re unsure whether your order qualifies or just want to ask a question, don’t hesitate to reach out. We’re here to make sure you feel confident before and after your purchase.
We’d love to hear from you!
If you decided not to purchase today, we’d like to know what held you back. Your feedback helps us improve and serve you better.
Was it the price, product description, reviews, shipping options, or something else? Tell us what made you hesitate, and we’ll send you a 5% discount code for your next order (valid on select products).
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Contact us: https://gardengrowshop.com/pages/contact-us
- Or Email: Sales@gardengrowshop.com
Why Garden GrowShop?
We’re an authorized dealer for every brand we sell—so you’ll always get full manufacturer warranties, premium support, and authentic gear direct from the source.
✅ Fast, tracked shipping on all orders
✅ 100% safe and secure checkout
✅ No restocking fees on returns
✅ Friendly U.S.-based support when you need it
Have questions? We're here to help. Whether you're just getting started or scaling up a full grow, our experts can guide you to the right gear.
I love how much headroom there is. It doesn’t feel cramped at all, even with multiple raised beds and racks. The sunlight penitrates very well!
We’ve converted the Summit into a full-scale propagation area. Lots of space, great insulation, and quality construction throughout.
The Summit is built for serious growers. We needed something large and durable, and this delivered on both. Easily fits tall crops and shelving.
This is a heavy-duty greenhouse. It’s stood up to strong storms without a single issue. Highly recommend for those in harsher climates.
We debated on going smaller but are so glad we went with the Summit. It’s more greenhouse than we expected in the best way.