結構要求
Green roofs add weight, or dead load, to the roof of a structure that must be factored into its design. Besides the weight of the roof membrane and roof insulation, the weight of the living roof components, growing media (soil), and plants must be taken into consideration. The weight of the components is typically expressed as a saturated weight or wet weight.
綠色屋頂會增加建築物屋頂重量或凈載重，這點在設計時必須加以考慮。除屋頂防水層和保溫層的重量外，還要考慮生態屋頂構件、栽培媒介（土壤）和植物重量。構件重量壹般用飽和重量或濕重表示。
Some extensive green roofs can weigh little more than a traditional roof with ballast; however, this weight can increase substantially as the thickness of the soil is increased to accommodate the wider variety of plants that can be placed in an intensive green roof.
相比帶有壓載物的傳統屋頂，某些大型綠色屋頂重量多不了多少。但是，隨著大型屋頂上可栽培品種的增加及相應土壤的加厚，屋頂重量亦會隨之大幅增加。
The soil for a green roof typically weighs between 5.0 to 7.0 pounds per square foot per inch of depth (wet or saturated weight), so on a typical extensive green roof, a 3 inch depth of soil would add 15.0 to 21.0 pounds per square foot. This spread in weight is largely dependent on the composition of the soil and can vary between green roof providers. You should typically plan for an additional 3 – 5 pounds per square foot of load for the remaining components in a complete assembly.
綠色屋頂上1平方英尺大小1英寸深的土壤重量壹般在5.0至7.0磅之間（濕重或飽和重量），所以1 ft* 1 ft* 3 in的土壤就會帶來15.0到21.0磅的增重。所鋪土層的重量大部分取決於土壤成分，並可能因綠色屋頂供應商而異。考慮到完整裝配中的剩余組件，妳壹般應該為其預留出3-5磅的荷載重量。
（第壹句中"that must be factored into its design”我不是很懂。有些地方可能不符合專業表達，樓主可相應修改。）