This freestanding greenhouse can be easily enlarged to meet the demands of expanding plant collections. It assembles without tools and can be extended simply by snapping additional frame sections on to the main unit (additional sections sold separately below). The greenhouse is completely weather-resistant and comes with four panel-and-rib sections that attach end-to-end, providing 50 square feet of growing space. The panels are durable polycarbonate that provide insulation, strength, and superior light diffusion, and the ribs are lightweight, stable plastic resin that will stand up to the elements for years. Because the polycarbonate panels are strong without being brittle, they are much safer than glass, while still providing the effective transmission of sunlight that is vital for plant photosynthesis. The door closes snugly to help preserve warmth accumulated during the day and to help keep out cool air at night, and a roof vent and back window (vent and window sold separately below) allow the passage of fresh air. Barn-shape design gives more headroom and growing space than traditional A-shape houses. 78 3/8" H x 65 1/2" W x 101 7/8" D. (177 lbs.) Although the basic unit can be installed directly on the ground, the addition of a base (sold separately at right) is recommended. Express and Premium Delivery not available for this item.