Sustainable Design: Green Roofs, Walls, and Vertical Gardens

SUSTAINABLE DESIGN GREEN ROOFS, WALLS, AND VERTICAL GARDENS

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TABLE OF CONTENTS CHAPTER 1: GREEN ROOFS .............................................................. 04 CHAPTER 2: GREEN WALLS AND VERTICAL GARDENS ...................... 12 CHAPTER 3: CASE STUDIES .............................................................. 22 SOURCES .......................................................................................... 26

BY: AUTUMN STUART AND DANIELA CINTRON LAUZURIQUE

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CHAPTER 1

GREEN ROOFS

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Roof gardens, also known as green roofs can be defined as a living system that is an extension of a roof. This green space can be below, at or above grade involving systems where plants are not planted in the ‘ground’.1 From a technical solution, the architect Le Corbusier considers that roof gardens are a fundamental component in which a contemporary city must

have. A roof garden is an open space where the human mind and body can experiment and truly connect with its surroundings through the blending of urban living, sun, sky, vegetation, and plants all into one.

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HOW DOES ROOF GARDEN DESIGN IMPROVE THE LONGEVITY OF ROOFS? The inclusion of a rooftop garden increases the lifespan of your roof by 20 to 30 years. It protects your roof from harsh climatic conditions and regulates the temperature in the building thereby reducing utility bills. It also provides flora and fauna for the building and allows nature to infiltrate the building.2

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WHAT TYPE OF PLANTS ARE IDEAL? When considering which plants to grow on a rooftop garden it is important to pick plants that will preferably require low maintenance, will tolerate possible windy conditions and great exposure to sunlight. For example, sedums, sempervivum, delosperma, grasses, sunflowers, dianthus, alyssum, thymus, and jovibarba are some of the most commonly used plants for rooftop gardens. In addition, native plants are also becoming very favorable to use in green roofs because they can easily adapt to local weather conditions. It is important to research and make sure that one considers factors such as climate adaptation, aesthetics, maintenance in order to pick the right plants to grow in a green garden.3

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WHAT SHOULD BE CONSIDERED? When deciding to design and build a roof garden, there are some key factors one has to 8 inches. Some advantages of designing some of these roof gardens include the to consider. For example, one needs to verify that the structure of the roof is going to following: the ability of having a great variety of plants and biodiversity, better stormbe able to hold up the weight of the roof garden. The roof must be able to withstand water management and insulation properties, accessibility, daily use, and a greater 5

the additional weight of elements such as the building materials, plants, furniture, chance for design development. The exposure to light is another factor to take growing substrate, etc. Depending on the weight capacity of the roof, preferably into consideration while building a roof garden. The plants will most likely receive consulted by a structural engineer, it will determine whether or not one can build sunlight and heat most of the day. There needs to be a good balance, therefore the 4

an extensive (shallow) or an intensive (deep) roof garden. An extensive roof garden design and placement of shaded areas for the plants that need it is very important. can weigh anywhere between 15-55 pounds per square foot. These shallower green In addition, the incorporation of wind break is also important because in places with roofs are typically 4 to 6 inches deep. A few of the advantages of having an extensive adverse weather conditions it will benefit the vegetation. Other elements that are green roof include: low weight, low maintenance and low irrigation, low capital important to have in mind while designing these gardens include: the accessibility investment, are more appropriate for larger areas, and are also easier to replace. to the garden, the implementation of waterproof outlets for operating tools and On the other hand, intensive green roofs can weigh anywhere between 80-150+ gardening equipments, irrigation systems, drainage, waterproofing, and the plants pounds per square foot. The growing medium for these roof gardens can exceed 6

that will be grown in the garden.

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WHAT ARE THE ADVANTAGES? Contemporary green roofs have many benefits that are increasingly being identified, measured, and acknowledged by the general public. Green roofs help the environment, the community and society, and they also have economical benefits. They can be divided into three categories: public, private, and design specific. The public benefits are more likely to foster the adoption of planning policies and regulations by local and city authorities to encourage green-roof construction for a better quality of life/environment, and for greater long-term cost-efficiency and benefit for local taxpayers and citizens.6 These include aesthetic improvements to the building, waste diversion, storm-water management, moderation of the urban heat island effect, improvements in air quality, new amenity spaces are formed, and it can even create local jobs. In addition, it is beneficial because it allows for the opportunity to grow food and plants and enhance the biodiversity of urban areas, all while helping improve the health and well being of others. Some of the more private benefits include the reduction of heating and cooling costs for the building, making it energy efficient, it can increase the roofing membrane durability, helps with the reduction of electromagnetic radiation, fire retardation in case of overheating, noise reduction, LEED accreditations, and many other benefits follow. On the other hand, some disadvantages of designing a roof garden include the maintenance it requires (some more than others), and the cost. Installations for green roofs are roughly around $10 to $24 USD per square foot, and also require initial investments.7 9

11 NAMBA PARKS, JAPAN

ROOF GARDENING AROUND THE WORLD 10

10 TORRE GUINIGI, ITALY

12 CHONGQING TAOYUANJU COMMUNITY CENTRE, CHINA

13 PARKROYAL ON PICKERING, SINGAPORE

14 MILL VALLEY CABINS, CALIFORNIA

Roof gardening has become one of the most innovative and rapidly developing fields in the world of the built environment. Since so much green space is being lost while developing cities, roof gardens have become a vital function in these high-density urban areas. This new concept is slowly becoming more popular and attracting more interest. In the United States, the usage green roofs has grown by 35% over the years. Other cities around the world are also starting to create regulations and plans in order to increase the usage of these gardens. For example, as of today, 16 different countries make up the European Federation of Green Roof and Wall Associations, which started in 1997. Their members (including: Austria, Germany, Switzerland, Belgium, France, Scandinavia, Hungary, Italy, Czech Republic, England, Portugal, among others) actively promote the use of green roofs and green facades in other to contribute to help alleviate and contribute to climate change. Germany is the leader worldwide in research and usage with the number of green roofs increasing 10-15% every year, but other cities such as Tokyo and Toronto have made it mandatory for all new construction to have at least 20-50% greenery in their rooftops.8 Every year, more and more countries join the movement as they become aware of the long term benefits these gardens provide.

Climate change has already been acknowledged as a reality in which the extremes of the weather are becoming more and more common. With the development of roof gardens, these address two of the key elements of that changing climate: increased frequency of severe rainstorms and associated flooding, urban temperatures and associated atmospheric pollution. Although these gardens are not the only solution, they have proven to work best in tandem with other measures.9

CHAPTER 2

GREEN WALLS AND VERTICAL GARDENS

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Green walls and/or vertical gardens are a beautiful mixture of nature and human interaction. They have been found naturally throughout history but in the past years have become a cultural phenomenon in architecture and design. Green walls can be divided into three major categories: green facades, living walls, and retaining living walls.10 Each installation is unique and therefore their technical performances vary by region and

climate as well as the building of placement. Green walls are also common in indoor circumstances. In the more recent years they are frequently being grown in corporate offices and public buildings, and even in some situations, residential locations.

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EXTERIOR HOW IS PROPER SUNLIGHT ADDRESSED? When it comes to the basics of starting a green wall or garden there are some issues that need to be sorted out. Sunlight and proper lighting is a big part in the life-cycle of a living wall. Photosynthesis cannot occur if the wall is not getting enough light and creating its natural nutrients. At the same time, the wall cannot overheat and cause dryness in the plants. There is a sweet spot in the middle where the balance of both sun and shade ensure the walls lifespan.

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WHAT TYPE OF PLANTS ARE IDEAL?

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Vertical gardens and walls can be theoretically be covered in anything pleased. In the most successful cases the ideal plants used are resistant and adaptable. Ferns and Ivy that flourish in heavy sunlight and require little maintenance are favorable. Plants that are known to conserve water, are low growing, can grow in a range of soil types and pH levels are also a plus. When bringing in color, petunias and succulents are excellent choices based on their smaller root systems and can endure heat and drought hardiness. Vegetables and herbs are also smart choices such as cabbage, spinach, select types of onions, chives, and even oregano.11 The most effective plants follow these rules and are capable of living year round.

WHICH LOCATIONS ARE OPTIMAL?

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Location for exterior living walls is an important decision that needs to be questioned. Warmer more tropical climates are optimal spots but are not limited to. Plants and foliage can be adjusted to fit the weather at hand. Locations that have a general consistent climate is most preferable. After dealing with climate there is an issue of the specific site or building the green wall will be placed. In urban contexts they need a strong combination of direct sunlight and shading. Because of this, its placement on a vertical surface depends on the direction of the sun as well as surrounding buildings ability to cover and shade at different points in the day.

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WHAT ARE THE ADVANTAGES? The benefits to green roofs is an ever expanding list of pros with few cons. On exterior surfaces, especially in urban settings they are proven to reduce urban heat island effect and smog, improve air quality, acts as a soundproofing barrier, and reduces energy usage due to conduction. They also are huge aesthetic improvements and allow for increased real estate value. Vertical gardens could potentially become a local community food source and create foot traffic for the area. Some of the few disadvantages are their limited growing space and potential to be messy as well as cost issues and their maintenance requirements.12 22

INTERIOR HOW IS PROPER LIGHTING ADDRESSED? From in indoor perspective, the wall or garden must receive the same treatment as the natural qualities and outdoor wall would be able to receive. Thanks to modern technology this is an achievable task. The challenge in an interior setting is ensuring just the right amount of artificial light that it closely mimics direct sunlight. LED lighting is most accurate in ensuring similar outcomes as the sun would provide.13 But a healthy indoor green 25

wall or garden have a combination of artificial lighting as well as indirect sunlight through windows, etc. A

WHAT TYPE OF PLANTS ARE IDEAL?

benefit of interior living walls is an easier way to control

The plants that are most ideal for indoor locations are best when from tropical settings either from

the shade for one can just simple turn off the lights.

the southern hemisphere or, if staying close to home, southern states like Florida. One of the main requirements is that they exhibit a wide range of tolerances.14 A minor requirement for sustaining a green walls life is keeping the temperature of the building at a fair consistent level. If the temperature 23

is ever radically changed, its plant life will most likely suffer.

WHICH LOCATIONS ARE OPTIMAL? When it comes to the placement of green walls or gardens, the answer shouldn’t be too hard to find.

They can be fitted to both new buildings as well as refurbished locations. The biggest dilemma when choosing a spot is the structural elements and support of the wall, but with a little upfront investment money and the right people, a wall can be fitted almost anywhere you can please. Indoor locations will require a frame that can be attached to the wall, with a waterproofing barrier to protect the existing structure.15 As stated earlier, green walls have been built in huge commercial developments several 18

stories high as well as in quaint little locations in virtually anyone’s private home.

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WHAT ARE THE ADVANTAGES? As long as these walls are continually maintained, they can potentially reach a life span of almost 25 years or until the plants life themselves. One of the largest factors in maintenance is the watering process, but again, thankfully to modern tech, is an already resolved issue. In typical constructions, there will be a drip-irrigation for watering purposes installed. In a public or commercial setting, green walls will most likely be using city water that is being pumped into the wall from external sources. The most efficient watering systems occur on a schedule and are drained properly. The benefits of indoor living walls are extensive. From an environmental standpoint, they improve energy efficiency, indoor air quality, and help noise reduction. In commercial sense or public building, green walls or gardens increase real estate value and have marketing potential. They can also be used for on-site wastewater treatment. Finally, from a stance of person benefits, green walls are proven to increase health and well-being. Some of the only disadvantages and the reason everyone doesn’t create a green wall is the cost, both upfront and continental, as well as the upkeep and maintenance.16

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CHAPTER 3

CASE STUDIES

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PARIS, FRANCE The Museé du Quai Branly is located in Paris that features a 40-foot high and 650-foot long extravagant green wall. It stands within walking distance of the Seine river, allowing for a stunning Eiffel tower as the backdrop and is one of the most photographed living walls to date.. Designed and planted by Gilles Clément, a garden and landscape architect and Patrick Blanc, a botanist and the creator or vertical gardens. To enter the museum, visitors must experience the breathtaking views or the exterior details as well as swirling paths and secret gardens. The project was built in 2005 and is open to the public. Its system is a single source provider and stands at a complete 90 degree angle. It showcases a selection of plant species from the world’s main temperate zones, specifically the northern hemisphere. Its biodiversity represented on the wall echoes the exquisite diversity of artists inside the museum. It took roughly 2 months for installation due to its massive size and was 100% completed and opened a little bit into 2006. The wall remains healthy at its current 13 year lifespan. A New York Times article entitled “Quai Branly: A perverse, magical space” read “By contrast, the exterior of the building is swallowed up by the vertical carpet of exotic plants punctured by big windows. On some stories the plants invade the building, crawling down the interior walls.” It then continued by praising the design, “When you put in little flowers, people are happy.”17 24

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SINGAPORE, SINGAPORE The green roof at the Nanyang Technological University’s School of Art, Design, and Media in Singapore offers a green roof like no other. When you think of a green roofs location its the roof, a usually untouchable spot only accessed through the building. The design in this situation allows for students, faculty, and others to experience the space as a rolling hill, accessible from the ground level. The location becomes a gathering space of the nonlinearing thinker that technology now allows. The greenery only accentuates the contrasting glass facade the rest of the building showcases. And though it’s nice to look at, architecturally, the roof adds so much more. It becomes and insulation device for the buildings, that can harvest rainwater and cools the surrounding air. The project was

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completed in 2006 and is open to the public. Its roughly 100,000 sq.ft. allows for a little bit of play time for the students and faculty during their heavy schedules. At a nearly $38 million to build it was officially opened in April of 2009. Rain sensors were installed on the roof to automate the irrigation process whereby irrigation is ceased when it rains. A rainwater collection system is also in place. The green roof and high performance glass as well as the use of carbon dioxide sensors in its air-handling units help to reduce energy used and maintain a healthy indoor air quality.18

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IMAGE SOURCES 1. Mossy Roof. Photograph. https://orig00.deviantart.net/be58/f/2011/080/b/3/ mossy_roof_by_culatte-d3c5x4q.jpg.

2. Interior Green Wall. Photograph. https://img2.cgtrader.com/items/706186/ cbb36b56f2/vertical-garden-1-3d-model-max-obj-fbx-c4d-stl-mtl.jpg.

3. Green roofs. Photograph. https://i.pinimg.com/originals/c4/74/6c/ c4746c94ad63ab67f7f817b926ad80c5.jpg.

4. Baltimore roof. Photograph. http://www.greenroofs.com/projects/baltimore_cc/ baltimore_cc1.gif.

5. Terraced Roof Garden. Photograph. http://thepeakmagazine.com.sg/wp-content/ uploads/2016/06/24.-View-of-the-terraced-roof-garden._result.jpg.

6. Casa Vallarta. Photograph. http://www.greenroofs.com/projects/ casa_vallarta_greenroof/casa_vallarta_greenroof11.jpg.

7. Cira Green. Photograph. http://www.greenroofs.com/projects/cira_green/ cira_green7.jpg.

8. Fukuoka Kenta Mabuchi. Photograph. https://webpages.uidaho.edu/larc380/new380/ assets/images/greenRoofFiles/images/CC/ACROS_FukuokaKentaMabuchiCC-BY-SA-2. jpg.

9. Chicago Green Roof. Photograph. https://news.nationalgeographic.com/content/dam/ news/2015/03/27/greenroofgallery/01greenroof.jpg.

10. Torre Guinigi Tower. Photograph. http://4.bp.blogspot.com/-AQ_FWytX9AM/ UQQ5ViI-RTI/AAAAAAAAjeo/lQ3jT5CfvjY/s1600/ Torre+Guinigi+Tower+Lucca+Tuscany+Italy+1.jpg.

11. Japan Roof. Photograph. https://rumahijau1.files.wordpress.com/2013/03/ namba_parks03.jpg.

12. China Roof. Photograph. https://images.adsttc.com/media/images/5637/d292/e58e/ ce6e/6400/0030/slideshow/01(2).jpg?1446498947.

13. Singapore Roof. Photograph. https://s-ec.bstatic.com/images/hotel/max1024x768/ 214/21441842.jpg.

14. Mill Valley Cabins. Photograph. http://feldmanarchitecture.com/wp-content/ uploads/2017/04/mill_valley_cabins9.jpg.

15. Indoor Wall. Photograph. http://i0.wp.com/www.urbangardensweb.com/wp-content/ uploads/2014/01/green-wall-italy.jpg.]

16. Long Wood Gardens. Photograph. http://www.loversiq.com/daut/as/f/i/ indoor-green-wall-with-awesome-long-leaved-grass-and-lots-of-brian-kwinn-has-0-subscribed-credited-from-www-prweb-com_indoor-wall-of- plants_office_small-home-office-design-suppose-dental-gallery-idea.jpg.

17. Outdoor Green Wall. Photograph. https://i.pinimg.com/originals/c1/78/a0/ c178a028c6bbedf47d0358aa52f4b825.jpg.

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18. Vertical Garden. Photograph. https://cdn.homedit.com/wp-content/uploads/2016/11/ Atlas-Hotel-Hoian-from-Vo-Trong-Nghia-Architects-with-Vertical-Gardens-on-Facade. jpg.

19. Garden Home. Photograph. https://inhabitat.com/wp-content/blogs.dir/1/files/2017/ 10/ZanonArchitettiAssociati.jpg.

20. Vertical Garden. Photograph. https://cdn.homedit.com/wp-content/uploads/2016/11/ Atlas-Hotel-Hoian-from-Vo-Trong-Nghia-Architects-with-Vertical-Gardens-on-Facade. jpg.

21. Skyline. Photograph. https://static.domain.com.au/domainblog/uploads/2017/04/ 09043813/2_gv3j63.jpg.

22. Exterior Gardens. Photograph. https://images.adsttc.com/media/images/5832/efbf/ e58e/cef8/7b00/04fc/large_jpg/AHH06_exterior_OKI.jpg?1479733176.

23. Decorative Green Wall. Photograph. http://ambushgallery.com/content/uploads/2016/ 02/20160225-WD_0167-2000x1335.jpg.

24. Foundry Square Green Wall. Photograph. http://www.habitathorticulture.com/system/ photos/foundry-square-iii/large/Foundry_layout2.jpg?1466044366.

25. Indoor Green Wall Ideas. Photograph. https://mir-s3-cdn-cf.behance.net/ project_modules/max_3840/b6ac8916511909.562acff59b758.jpg.

26. Decorative Green Wall. Photograph. http://ambushgallery.com/content/uploads/2016/ 02/20160225-WD_0167-2000x1335.jpg.

27. Indoor Plant Wall. Photograph. http://www.benevaplantscapes.com/wp-content/ uploads/2016/09/indoor_plant_wall.jpg.

28. Indoor Green Wall. Photograph. http://arafen.com/a/l/e/ exterior-green-wall-design-images-publishing-architecture-books-the-first-decadeof-living-biofilter-large-indoor-plant-photo-credit-university-guelph-humber-toro nto_indoor-living-wall_1080x1323.jpg.

29. Paris Museum. Photograph. http://www.greenroofs.com/projects/mqb/mqb8.jpg.

30. Science Center Green Roof. Photograph. http://www.greenroofs.com/projects/ ntu_singapore/ntu_singapore6.jpg.

31. Paris Living Wall. Photograph. https://news.nationalgeographic.com/content/dam/ news/photos/000/655/65557.jpg.

32. Musee Green Wall. Photograph. http://www.dudziak.com/pictures/europe_summer2007/ paris/misc/musee_du_quai_branly_2_1600.jpg.

33. Green Wall. Photograph. https://thissydneylife.files.wordpress.com/2012/08/ musee-du-quai-branly-4.jpg.

34. Green Roof Singapore. Photograph. http://www.greenroofs.com/projects/ ntu_singapore/ntu_singapore7.jpg.

35. Singapore Science Center. Photograph. https://greenroofhannahliu.files.wordpress.com/2015/05/image00054.jpg.

BIBLIOGRAPHY “About Green Walls.” Green Roofs for Healthy Cities. Accessed January 15, 2018. https://greenroofs.org/about-green-walls/.

Admin. “Quai Branly Museum.” Admin. September 14, 2017. Accessed January 15,

2018. https://www.verticalgardenpatrickblanc.com/realisations/paris/quai-branly-museum.

Blanc, Patrick. The Vertical Garden: From Nature to the City. New York, NY: W.

W. Norton & Company, Inc., 2008.

Dunnett, Nigel, and Noël Kingsbury. Planting Green Roofs and Living Walls.

Portland, OR: Timber Press, Inc., 2008.

“Green Cities in Europe.” European Federation Green Roofs and Walls. Last

modified June 13, 2017. Accessed January 14, 2018. http://efb-greenroof.eu/

about-us/.

“Green Roof Benefits.” Green Roofs For Healthy Cities. Accessed January 14,

2018. https://greenroofs.org.

Greenroofs.com Projects - Nanyang Technological University (NTU) School of Art,

Design and Media (ADM). Accessed January 15, 2018. http://www.greenroofs.com/projects/pview. php?id=846.

Matt. “Green Roofs at Nanyang Technological University’s School of Art, Design, and

Media | CPG Consultants.” Arch2O.com. November 18, 2016. Accessed January 15, 2018.

https://www.arch2o.com/green-roofs-at-nanyang-technological-universitys-school-of-art-design-and- media-cpg-consultants/.

Nishikura, Megumi. “Grow a Green Roof.” Our World (blog). Entry posted November

9, 2009. Accessed January 15, 2018. https://ourworld.unu.edu/en/

grow-a-green-roof.

Plant Species Guide for Wall Garden Vertical Gardens. Accessed January 15, 2018. https://wallgarden.com.au/vertical-garden-plant-species-guide.

“The Museé du Quai Branly in Paris Boasts a Lush 650-foot Green Wall by Patrick

Blanc.” Inhabitat Green Design Innovation Architecture Green Building. October 03, 2012. Accessed January 15, 2018.

https://inhabitat.com/the-musee-du-quai-branly-in-paris-boasts-a-luscious-vertical-garden-by-pat rick-blanc/.

“Top 4 Green Roof Plants.” Do It Yourself (blog). Accessed January 15, 2018.

https://www.doityourself.com/stry/top-4-green-roof-plants.

Weiler, Susan K., and Katrin Scholz-Barth. Green Roof Systems: A Guide to the

Planning, Design, and Construction of Landscapes over Structure. New

Jersey, United States: John Wiley & Sons, Inc., 2009.

“What are the Challenges of Having Living Green Walls?” Planters Group. Accessed

January 15, 2018. http://www.planters.ae/blog/challenges-of-having-living-green-walls.

“What to Consider When Designing and Building Your Own Rooftop or Balcony

Garden.” Projex (blog). Entry posted November 17, 2017. Accessed January

15, 2018. https://www.projex.com.au/blog/

what-to-consider-when-designing-and-building-your-own-rooftop-or-balcony-garden/.

ENDNOTES 1. Tolderlund, Leila. “Design Guidelines and Maintenance Manual for Green Roofs in the Semi-Arid and Arid West.” Epa.gov. November 10, 2010. Accessed January 16, 2018.https://www.epa.gov/sites/production/files/documents/GreenRoofsSemiAridAridWest.pdf.

2. “Green Cities in Europe.” European Federation Green Roofs and Walls. Last modified June 13, 2017. Accessed January 14, 2018.http://efb-greenroof.eu/ about-us/.

3. Nishikura, Megumi. “Grow a Green Roof.” Our World (blog). Entry posted November 9, 2009. Accessed January 15, 2018.https://ourworld.unu.edu/en/ grow-a-green-roof.

4. Dunnett, Nigel, and Noël Kingsbury. Planting Green Roofs and Living Walls.

Portland, OR: Timber Press, Inc., 2008.

5. “What to Consider When Designing and Building Your Own Rooftop or Balcony Garden.” Projex (blog). Entry posted November 17, 2017. Accessed January 15, 2018. https://www.projex.com.au/blog/ what-to-consider-when-designing-andbuilding-your-own-rooftop-or-balcony-garden/.

6. Tolderlund, Leila. “Design Guidelines and Maintenance Manual for Green Roofs in the Semi-Arid and Arid West.”

7. Ibid 8. “Top 4 Green Roof Plants.” Do It Yourself (blog). Accessed January 15, 2018. https://www.doityourself.com/stry/top-4-green-roof-plants.

9. Dunnett, Nigel, and Noël Kingsbury. Planting Green Roofs and Living Walls.

10. Ibid 11. “Green Roof Benefits.” Green Roofs For Healthy Cities. Accessed January 14, 2018. https://greenroofs.org.

12. Plant Species Guide for Wall Garden Vertical Gardens. Accessed January 15, 2018.

13.“About Green Walls.” Green Roofs for Healthy Cities. Accessed January 15, 2018.

14. “What are the Challenges of Having Living Green Walls?” Planters Group.

Accessed January 15, 2018. http://www.planters.ae/blog/challenges-of-havingliving-green-walls.

16. Admin. “Quai Branly Museum.” Admin. September 14, 2017. Accessed January 15, 2018. https://www.verticalgardenpatrickblanc.com/realisations/paris/ quai-branly-museum.

17. “What are the Challenges of Having Living Green Walls?” Planters Group.

18. Greenroofs.com Projects - Nanyang Technological University (NTU) School of Art, Design and Media (ADM). Accessed January 15, 2018. http://www.greenroofs.com/projects/pview.php?id=846.