what is this roof's disadvantage?
The initial installation cost can be double than that of a normal roof.
Green roof
The main disadvantage of green roofs is that the initial cost of installing a green roof can be double that of a normal roof. 
which part of the atmosphere does weather occur On Earth, most weather phenomena occur in the lowest level of the planet's atmosphere, the troposphere. what are its effects on human being? Climatic changes cause gradual drift of populations, and at times, extreme weather conditions may also affect historical events. does space also has it? Atmosphere is present on the planets within the solar system. which place is recorded for its extreme nature? The coldest air temperature ever recorded on Earth is , at Vostok Station, Antarctica and the hottest at 'Aziziya, Libya. has the coldest place's name ever changed? "Terra Australis". which animals are found at this place? The flightless midge "Belgica antarctica". how has the global warming effected it? Rise in sea level. who had explored this place in the past? In January 1840, an expedition team was led by the United States Exploring Expedition, under Lieut. Charles Wilkes. which plants are found here? Mosses, liverworts, "Deschampsia antarctica",  "Colobanthus quitensis" , and "Poa annua". what is the first one classified into? They are divided into eight classes. what is its commercial use? Florist trade and in home decorations. and traditional use? It was used for bedding , insulation and clothing. what is the benefits of using it as roofs? Reduced weight loads, increased water absorption, no fertilizer requirements, and high drought tolerance.
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Green roof [SEP] Disadvantages
The main disadvantage of green roofs is that the initial cost of installing a green roof can be double that of a normal roof. Depending on what kind of green roof it is, the maintenance costs could be higher, but some types of green roof have little or no ongoing cost. Some kinds of green roofs also place higher demands on the waterproofing system of the structure, both because water is retained on the roof and due to the possibility of roots penetrating the waterproof membrane. Another disadvantage is that the wildlife they attract may include pest insects which could easily infiltrate a residential building through open windows.