Not all greenhouses are built the same and the Monticello line of greenhouses by Riverstone Industries proves this to be true. The Monticello is applying good old American ingenuity to make the best product for our customers and help to elevate the industry standards of all greenhouses. Constructed from the highest quality extruded aluminum (US grade - not the thinner and more brittle foreign aluminum) and coated as not to discolor over the years (guaranteed to contain 0.0% lead), our greenhouse uses on average more than 70 lbs. more aluminum than the average imported greenhouse. Why is this important. The weaker the framework the less snow the greenhouse can hold in the winter time before collapsing on itself also the easier it will be get damages in wind. While most hobby greenhouses on the market us less expensive thinner walls and roofing materials (the crystal clear walls are as thin as 0.2 mm), the Monticello uses professional grade 8 mm twin wall polycarbonate. This is the same thickness as used in the commercial greenhouses. The twin wall polycarbonate acts as a double pain window keeping cooler air in during warm months and insulating the greenhouse from cold air in the wintertime. This not only makes the Monticello more efficient to grow in for a longer period of time than other greenhouses but it also adds to the efficiency of growing, cutting down electric bills for those who choose to grow year round.