"UN6L8 PAGE 7..What Are Green Roofs? Green roofs are a type of urban green space designed on the roof of a building or home. Green roofs are not simply potted plants on a roof. To be considered a green roof, the roof should be partially or completely covered with vegetation. A green roof also includes a growing medium, a drainage system, and a waterproofing structure. There are two types of green roofs: extensive and intensive. Extensive Green Roofs use low-growing plants such as mosses, herbs, succulents, and grasses have a soil depth of less than 6 inches have a dry weight of vegetation between 10 and 50 pounds per square foot require relatively minimal maintenance and have low start-up costs Intensive Green Roofs use a wide variety of plants, possibly including large shrubs and trees have a soil depth of 6 inches or more have a dry weight of vegetation between 50 and 150 pounds per square foot require significant structural support require routine maintenance and have high start-up costs"

Question

"UN6L8 PAGE 8...Green Roof Layers It is important for green roofs to be designed and installed properly. This keeps the building underneath safe and secure from leaks and damage. Proper installation also ensure the longevity of the plants on the roofs. The composition of green roofs varies, but all contain the layers shown in the illustration. Green roofs have many different layers, and each layer has a specific purpose: plants: the layer of vegetation visible to visitors of the green space growing medium: a mix made up of materials that ensure a suitable growing surface filter cloth: prevents growing medium and other materials from reaching drain drainage layer: drains excess water off the roof root barrier: helps protect membrane from being penetrated by roots waterproof membrane: overall protection for building underneath"

"UN6L8 PAGE 9... Benefits of Green Roofs Residential buildings in Sydney Australia are home to many green roofs. While green roofs are typically visually pleasing, they provide many other advantages as well. Urban green roofs provide both environmental and economic benefits to a city, and health benefits to its residents. Green roofs can protect and maintain biodiversity by allowing many different types of plants to coexist together. These plants can provide crucial habitats for insects. Urban green roofs also help to replace green spaces that were lost to buildings and infrastructure. In addition, green roofs can help with cost-saving efforts. Green roofs tend to last longer than traditional roofs, which helps reduce the cost of replacements. They also act as natural insulation, keeping heat out during the summer and inside during the winter. They increase the energy performance of buildings, as cooling and heating costs can significantly drop in buildings with green roofs. They also absorb and then slowly release stormwater, preventing runoff that can overwhelm and damage a city's sewer system. Green roofs can improve the health of residents who visit the roofs as well as those who don't. Green roofs improve air quality by absorbing pollutants and carbon dioxide, and producing oxygen. They help regulate the climate of a city, reducing extremes in temperature. Green roofs have been shown to promote mental health and relaxation for those who spend time in them, and green roof gardens can also provide a source of fresh, local produce."

"UN6L8 PAGE 10.. Disadvantages of Green Roofs While green roofs provide a multitude of benefits, they are not without drawbacks. The two biggest concerns when developing a green roof plan are: cost of installation maintenance costs If a house or building is not suitable for green roofing, it may require special modifications. In addition to this cost, the installation of the green roof layers can cost thousands of dollars more than a regular roof. The Environmental Protection Agency (EPA) estimates that the cost of installing an extensive green roof is about $10 per square foot. For intensive roofs, the cost is about $25 per square foot. In 2006, the University of Michigan researched the difference in cost between a traditional roof and a green roof. According to their research, the cost of a conventional roof covering 21,000 square feet was about $335,000, while the cost to install a green roof was about $464,000. This initial cost difference could be considered a disadvantage. However, the research also revealed that the overall lifetime savings of a green roof was about $200,000. Most of the savings came from decreased energy needs for the building. Once installed, the maintenance costs for a green roof include both time and money. Just as with any garden, a green roof must be consistently maintained. Watering plants, keeping them safe from pests, and ensuring the equipment is properly inspected are all part of the proper care of a green roof. According to the EPA, yearly maintenance costs for both types of green roofs can range from 75 cents to $1.50 per square foot."

"UN6L8 PAGE 11... Answer Think about reasons why a large city like New York would want to incorporate green roofs. Write down your answer. Possible response: A large city like New York City has many buildings and little area for green space. Adding green roofs would give the city more overall green space. The residents could benefit from less pollutants in the air. The costs of heating and cooling buildings with green roofs could be reduced. Green roofs would give the people of the city more green areas in which to gather."

> Paragraph Sentence Starters – Just fill in the blanks, then copy/paste into the essay box on your test! Remember to copy/paste the source we give you below in your answer!
Use U6L8 PAGES 7-11
There are two basic types of green roofs: (a) _______ and (b) _______.
(a) A ____ green roof uses plants that include _______. The soil depth is about _______. The weight of the plants is about _______. More support for the roof may include _______. The cost of keeping the roof green is _______.
(b) A ____ green roof uses plants that include _______. The soil depth is about _______. The weight of the plants is about _______. More support for the roof may include _______. The cost of keeping the roof green is _______.
Storm runoff is an important part of green roofs. The benefits are _______.
Here is a summary of the costs to start and maintain a green roof: _______.

Answer 1

Use U6L8 PAGES 7-11

There are two basic types of green roofs: (a) extensive and (b) intensive.
(a) A extensive green roof uses plants that include mosses, herbs, succulents, and grasses. The soil depth is about less than 6 inches. The weight of the plants is about 10 to 50 pounds per square foot. More support for the roof may include relatively minimal structural modifications. The cost of keeping the roof green is yearly maintenance costs can range from 75 cents to $1.50 per square foot.
(b) A intensive green roof uses plants that include a wide variety of plants, possibly including large shrubs and trees. The soil depth is about 6 inches or more. The weight of the plants is about 50 to 150 pounds per square foot. More support for the roof may include significant structural support. The cost of keeping the roof green is also subject to the yearly maintenance costs ranging from 75 cents to $1.50 per square foot.
Storm runoff is an important part of green roofs. The benefits are that they absorb and then slowly release stormwater, preventing runoff that can overwhelm and damage a city's sewer system.
Here is a summary of the costs to start and maintain a green roof: the installation cost for an extensive green roof is about $10 per square foot, and for an intensive roof, it is about $25 per square foot. Overall lifetime savings of a green roof can be about $200,000 due to decreased energy needs.