A great starter or grower greenhouse with polycarbonate walls and roof. Extend your growing season with this easy-to-assemble, efficient greenhouse that's made in the USA! Overview If your winters are long and cold, be sure you choose a greenhouse like this one with durable twin-walled polycarbonate panels. The Monticello is a sturdy and robust greenhouse, and it comes with all tools needed for assembly. It is available as a 8' x 8' basic model or with added 4' extensions up to 24 feet long. The interior roof peak is 7' 6" high and the side walls are 4' 10" high. It has a large 6 ft x 4 ft wide door opening. Each greenhouse and extension comes with an automatic venting system. Features & Benefits: Construction: Made from extruded aluminum with 8mm twin wall polycarbonate walls and roof and an integrated base that allows for direct anchoring to the ground or deck. The twin wall polycarbonate has superior insulating capabilities to provide ideal growing conditions in warm or cool weather. This robust design and high-quality aluminum allows the Monticello to withstand substantial snowfalls and high winds. The greenhouse has a snow load capacity of 24 lbs per square foot. Assembly: Twist & Lock nut and bolt fastening construction combined with ribbed design for quick interlocking results in a sturdy structure. We recommend setting aside a full weekend for assembly. Warranty: Made in the USA and comes with a 10-year manufacturer's warranty. Customize: Design this greenhouse to meet your needs by choosing your own frame, length and adding on optional accessories listed below. Each of the accessories can be custom ordered to fit the length of greenhouse you choose. Accessories: Work Bench System - the work station is a high-impact PVC vented platform with heavy-duty support bars that hold up to 600 lbs. The work station is designed for either side of the greenhouse and is very easy to install. For the 8 foot unit, the work station is 8' x 2' x 30". The work bench can be ordered to fit each length. There is a 10 year manufacturer's warranty on the work station. Shade Cloth - the Monticello shade cloth is a simple and thoughtful design to keep your greenhouse cool by reflecting heat and sunlight. It is installed on the inside of the greenhouse, is compatible with the vents and side windows, ships ready-to-use and requires no grommets for installation. Each shade cloth is made from heavy-duty, commercial-grade polyester weave that lets in 37 % light and includes bungee balls for tying. Automatic Watering System - this system is designed to be hung from the ceiling of the greenhouse with 2 weighted sprinkler heads separated by 4' spray in a circular pattern. The commercial-grade digital timer is designed to allow custom watering cycles depending on plant needs. The hose is designed specifically to prevent mold and bacterial growth and the system is compatible with the shade cloth. It can be installed in any 8' x 8' greenhouse. There is a 5 year manufacturer's warranty on the watering system. Additional Roof Vent - The automatic roof vent is designed for simple and easy installation. It is made from the same high-quality aluminum and polycarbonate as the entire unit and includes the same professional-grade automatic vent opener as is included with the standard greenhouse. There is a 10 year manufacturer's warranty on the vents. Additional length can be added to the greenhouse by adding 4' extensions, making it possible to extend the length of your greenhouse over time by ordering extension kits. Each extension kit includes a 2' x 2' roof vent with automatic opener and gutters. Exterior Base Dimensions: 8' x 8' Greenhouse: 101" x 101" x 90" 8' x 12' Greenhouse: 101" x 149.75" x 90" 8' x 16' Greenhouse: 101" x 198.25" x 90" 8' x 20' Greenhouse: 101" x 247" x 90" 8' x 24' Greenhouse: 101" x 295.75" x 90"