With twice the heat retention of typical greenhouses, these new Nature Series Greenhouses are superbly engineered for longer overwintering and earlier seed starting - a true advantage for your fruits, flowers and vegetables! The Nature Greenhouse is sure to catch your eye. It features a rust-resistant, brushed aluminum frame and heavy-duty galvanized steel base that is designed to stand the test of time. Your plants will love the diffused even light from the clear, twin-wall polycarbonate panels that have the added benefit of TWICE the heat retention of typical single-layer panels. Besides excellent thermal insulation, these 4mm panels have 100% UV-protection to block out 99.9% of harmful solar radiation, and are virtually unbreakable. The sturdy, corrosion-resistant aluminum frame features strong bolt-together connections that go together quickly and easily. Heavy-duty galvanized steel base kit will provide an easy way to anchor your greenhouse to your wood or concrete foundation. An adjustable roof vent and swinging door provide excellent ventilation. A gutter and downspout are included so you can conserve water by collecting that spring rainwater! Plus it's roomy with 6.5 feet of headroom. Average setup time of 4 to 5 hours. Dimensions are 72.25in L x 73in W x (53in side H or 85in apex height). Door is 2ft wide by 6ft high. Want 33% more room? Then go for the Nature 6x8 Greenhouses. Dimensions are 96.25in L x 73in W x (53in side H or 85in apex height).