The best type of green roof for the hotel's space, which can only support about 20 pounds per square foot, is an extensive green roof.
Extensive green roofs are lightweight, typically designed with shallow soil depths and a limited selection of drought-resistant plants, making them easier to maintain and suitable for roofs with weight limitations. Intensive green roofs, on the other hand, require deeper soil and support heavier plant types, which would exceed the weight limit in this case.