This document provides an overview of green roofing, including its description, construction methods, layers, hydrologic cycle impacts, stormwater management benefits, costs and benefits. It discusses two main types of green roofs - extensive and intensive. Extensive roofs have shallow growing media and drought-resistant plants, while intensive roofs support a wider variety of plants and require deeper growing media. The key layers of a green roof are vegetation, growing media, drainage, root barrier, waterproof membrane and insulation. Green roofs can reduce stormwater runoff by absorbing and retaining rainfall, and help regulate urban temperatures through evapotranspiration. They provide environmental and economic benefits but also have higher initial costs than traditional roofs.
A vegetated roof, or green roof, is a layered system installed on top of a roof that includes vegetation growing in a lightweight soil medium. It provides environmental benefits like decreased stormwater runoff and reduced energy usage. There are two types - extensive roofs have shallow soil depths under 6 inches while intensive roofs have deeper soil and support a greater variety of plants but require more maintenance. Initial installation costs of vegetated roofs are higher than traditional roofs but they provide long-term savings and last longer through better insulation and protection from temperature fluctuations.
Analysis of Upgradation of a Convectional Building into Green BuildingIJSRD
The phenomenon of global warming or climate change has led to many environmental issues including higher atmospheric temperatures, intensive precipitation, and increased Greenhouse gaseous emission and of course increased indoor discomfort condition. Researchers worldwide collectively agreed that one way of reducing the impact of global warming is by implementing Green Roof Technology which integrates vegetation, growing medium and water proofing membrane on top of the roof surface. This study emphasized to first analysis a convectional Building than upgrade it to a Green Building by the use of some Eco- Friendly materials. In addition to this by the use of some smart electrification work we can also conserve an ample amount of energy in a Convectional Building. Than by the use of different agencies which would provide checklist for Green Building we can rate a Convectional Building which is been upgraded into a Green Building..The objectives of this research were is Reduction in the indoor temperature of the room contributes reduction in energy consumption in the building. By the use of smart electrification an ample amount of energy can also be conserved. By the use of eco- friendly materials and waste products an ample amount of money can also be saved. Although by the up gradation of convectional building the initial cost will be high because of the use of some special material such as solar panel, rain water harvesting system but their application will return 10 times of what we invested
While work is ongoing to further define the benefits of what has been termed Above-Sheathing Ventilation (ASV), the significance of this information is likely to create a very strong impetus for change in how tile roofs are installed.
Planning Green roofs and Green Walls Structural designOláh András Béla
The document discusses the history and design of green roofs. It provides two historical examples - the Hanging Gardens of Babylon, which was one of the first green roofs built using layers of reeds and brick, and the Scandinavian sod roof, which utilized multiple layers of birch bark and sod. Modern green roof technology began in the 1960s in Germany when waterproof membranes became available. There are several structural layers involved - a filter membrane, drainage layer, root barrier, waterproof membrane, and insulation. The design can vary depending on whether it is an intensive or extensive green roof.
Selecting Plants for Extensive Green RoofsFarrah85p
This document discusses plant selection considerations for extensive green roofs in the United States. It defines extensive green roofs as having shallow media depths of less than 6 inches and requiring minimal maintenance. When selecting plants, key factors to consider include climate, media composition/depth, drought tolerance, and aesthetic goals. The document provides a table of over 80 plant species that have been scientifically tested or are recommended by growers as suitable options for extensive green roofs across different regions of the US.
This document summarizes Garland Sustainable Roofing Solutions' portfolio of high-performance and sustainable roofing products. It discusses five key ways roofing can be sustainable: through recycled materials, recyclable materials, extended service life, efficient resource use, and renewable energy. The portfolio includes products that provide sustainability through these categories, such as vegetative roofs, reflective coatings, and solar panels. The document emphasizes longevity, reflectivity, vegetative roofs, and photovoltaic systems as particularly important sustainable solutions.
The document discusses roof gardens/green roofs, including their benefits, different types, construction considerations, and plant selection factors. Roof gardens can provide temperature control, stormwater management, and wildlife habitat, while reducing the urban heat island effect. Gardens are constructed in layers over the waterproof roof with varying soil depths and plant types. Design must consider the roof's structural capacity and drainage. Choosing hardy plants suited to the sun/wind exposure is important for low maintenance.
Planning Green Roofs and Green Walls Ecological and climatic effectsOláh András Béla
The document discusses the ecological and climatic effects of green roofs. It notes that green roofs are not suitable everywhere and their effectiveness depends on local climate conditions. Green roofs can help mitigate urban heat islands and reduce temperature extremes. They also slow rainfall absorption to reduce stormwater loads. However, green roofs may increase mosquito habitats near buildings. Overall, properly planned green roofs can provide environmental benefits but also have disadvantages to consider regarding local ecology and public health.
A vegetated roof, or green roof, is a layered system installed on top of a roof that includes vegetation growing in a lightweight soil medium. It provides environmental benefits like decreased stormwater runoff and reduced energy usage. There are two types - extensive roofs have shallow soil depths under 6 inches while intensive roofs have deeper soil and support a greater variety of plants but require more maintenance. Initial installation costs of vegetated roofs are higher than traditional roofs but they provide long-term savings and last longer through better insulation and protection from temperature fluctuations.
Analysis of Upgradation of a Convectional Building into Green BuildingIJSRD
The phenomenon of global warming or climate change has led to many environmental issues including higher atmospheric temperatures, intensive precipitation, and increased Greenhouse gaseous emission and of course increased indoor discomfort condition. Researchers worldwide collectively agreed that one way of reducing the impact of global warming is by implementing Green Roof Technology which integrates vegetation, growing medium and water proofing membrane on top of the roof surface. This study emphasized to first analysis a convectional Building than upgrade it to a Green Building by the use of some Eco- Friendly materials. In addition to this by the use of some smart electrification work we can also conserve an ample amount of energy in a Convectional Building. Than by the use of different agencies which would provide checklist for Green Building we can rate a Convectional Building which is been upgraded into a Green Building..The objectives of this research were is Reduction in the indoor temperature of the room contributes reduction in energy consumption in the building. By the use of smart electrification an ample amount of energy can also be conserved. By the use of eco- friendly materials and waste products an ample amount of money can also be saved. Although by the up gradation of convectional building the initial cost will be high because of the use of some special material such as solar panel, rain water harvesting system but their application will return 10 times of what we invested
While work is ongoing to further define the benefits of what has been termed Above-Sheathing Ventilation (ASV), the significance of this information is likely to create a very strong impetus for change in how tile roofs are installed.
Planning Green roofs and Green Walls Structural designOláh András Béla
The document discusses the history and design of green roofs. It provides two historical examples - the Hanging Gardens of Babylon, which was one of the first green roofs built using layers of reeds and brick, and the Scandinavian sod roof, which utilized multiple layers of birch bark and sod. Modern green roof technology began in the 1960s in Germany when waterproof membranes became available. There are several structural layers involved - a filter membrane, drainage layer, root barrier, waterproof membrane, and insulation. The design can vary depending on whether it is an intensive or extensive green roof.
Selecting Plants for Extensive Green RoofsFarrah85p
This document discusses plant selection considerations for extensive green roofs in the United States. It defines extensive green roofs as having shallow media depths of less than 6 inches and requiring minimal maintenance. When selecting plants, key factors to consider include climate, media composition/depth, drought tolerance, and aesthetic goals. The document provides a table of over 80 plant species that have been scientifically tested or are recommended by growers as suitable options for extensive green roofs across different regions of the US.
This document summarizes Garland Sustainable Roofing Solutions' portfolio of high-performance and sustainable roofing products. It discusses five key ways roofing can be sustainable: through recycled materials, recyclable materials, extended service life, efficient resource use, and renewable energy. The portfolio includes products that provide sustainability through these categories, such as vegetative roofs, reflective coatings, and solar panels. The document emphasizes longevity, reflectivity, vegetative roofs, and photovoltaic systems as particularly important sustainable solutions.
The document discusses roof gardens/green roofs, including their benefits, different types, construction considerations, and plant selection factors. Roof gardens can provide temperature control, stormwater management, and wildlife habitat, while reducing the urban heat island effect. Gardens are constructed in layers over the waterproof roof with varying soil depths and plant types. Design must consider the roof's structural capacity and drainage. Choosing hardy plants suited to the sun/wind exposure is important for low maintenance.
Planning Green Roofs and Green Walls Ecological and climatic effectsOláh András Béla
The document discusses the ecological and climatic effects of green roofs. It notes that green roofs are not suitable everywhere and their effectiveness depends on local climate conditions. Green roofs can help mitigate urban heat islands and reduce temperature extremes. They also slow rainfall absorption to reduce stormwater loads. However, green roofs may increase mosquito habitats near buildings. Overall, properly planned green roofs can provide environmental benefits but also have disadvantages to consider regarding local ecology and public health.
A brief overview about the green building strategy known as green roofing. This presentation was originally prepared for St. Louis regional educators who attended the 2014 Sustainability Institute for P12 Educators.
The document discusses green roofs and their implementation in Erbil City. It provides background on green roofs, their history and types. The document finds that Erbil has a low percentage of green areas at 6.5% compared to an international standard of 30%. It recommends implementing extensive and semi-intensive green roofs on individual building projects in Erbil to increase green space. On a city scale, the document suggests leaders support green roof laws and increase public awareness of their environmental benefits.
- Green roofs originated in Germany in the 1960s and 1970s as a way to replace natural spaces lost to rapid urbanization. They provided benefits like stormwater retention and temperature regulation.
- German research in the 1970s and standards established in the 1980s helped establish green roofs as an industry. By the 1990s there were an estimated 160 million square feet of green roofs in Germany, 95% of which were extensive lightweight sedum roofs.
- Proper installation requires following manufacturer specifications and industry standards. Key components include a waterproof membrane, filter fabric, drainage layer, growth medium, and plants. Safety, positive drainage, and compliance with local building codes are also important considerations.
This document discusses green roofs and their benefits. It begins by defining green roofs as roofs covered in vegetation rather than just a waterproof membrane. There are two main types of green roofs - extensive and intensive. Extensive green roofs are lighter and require less maintenance while intensive green roofs can support a wider variety of plants. Green roofs provide multiple benefits such as absorbing rainwater, providing insulation, creating wildlife habitats, and reducing the urban heat island effect. They can also improve air quality, increase energy efficiency, and extend the lifespan of roofs. The document examines these benefits in further detail.
David O Dowd's document discusses green roofs. It defines green roofs as roofs covered with organic material like moss or turf. There are benefits to using green roofs such as reducing heating/cooling costs, absorbing rainfall, and reducing CO2 emissions. The three main types of green roofs are intensive, semi-intensive, and extensive. Extensive green roofs, which use shallow soil and low-maintenance plants, are most applicable for homes. The document outlines the construction process for an extensive green roof and provides examples like Gary Neville's passive house with a full green roof.
The document discusses the benefits and components of green roofs. Green roofs can reduce urban heat, lower energy costs, improve air and water quality, and provide habitat. They are composed of a waterproof membrane, drainage layer, insulation, filter fabric, growing medium and plants. Extensive green roofs are lighter weight and have shallow growing media while intensive roofs support deeper media and larger plants. Proper planning is needed to coordinate a green roof installation with other construction trades and address scheduling, access, and potential damage from other work.
Green roofs, also known as eco-roofs or roof gardens, are gardens that are installed on top of buildings. There are two main types - extensive green roofs use sedum plants and only require 4 inches of soil, while intensive roofs can support a wider variety of plants and deeper soil. Green roofs provide multiple benefits such as reducing energy usage, absorbing stormwater, filtering air pollution, and creating wildlife habitats. They are made up of layers including a waterproof membrane, root barrier, drainage mat, and lightweight soil mix of aggregate and organic material to support plants. Green roofs are best installed on flat or low-sloped roofs but stabilization may be needed on steeper slopes.
This presentation gives a basic information about green roofing technology with easy English in a simple way. It has been used for conducting data about a study on "Assessing the awareness about green roofing technology and the effect of lecture on it. It is with minimum words and maximum content.
Role of plants in climate responsive buildingSurbhi Sharma
This document discusses the role of plants in climate responsive design and landscaping. It describes how macroclimate and microclimate affect plant selection and placement. Plants can be categorized as trees, shrubs, vines, ground covers, and turf grasses. Their placement is important for controlling solar radiation, wind, and humidity. Evergreens provide benefits in hot dry climates while deciduous plants are suitable for northern and southern exposures. Plant selection also depends on temperate, cool, hot-humid, or hot-arid climates. Overall, landscape design with native plants can help moderate temperatures and direct airflow to optimize building performance.
This document is to give an insight on green roofing system, comparing it to the traditional and modern roofing system and also enumerating some key advantages of the new or green system to the environment.
This document provides an overview and planning guide for Garden Roof® assemblies produced by Hydrotech. It discusses the benefits of green roofs, including reducing the urban heat island effect and stormwater runoff. It also outlines Hydrotech's approach to garden roof assemblies, which incorporates a monolithic membrane roof and proven green roof technologies. The document describes extensive, intensive, and lawn garden roof assembly types and lists their key components, such as growing media, drainage layers, and suitable plant types. Installation and maintenance considerations are also addressed.
This document discusses green roofs and their benefits. It provides examples of four different types of green roof designs: 1) Wave House with various plant varieties in a sine wave design; 2) Mill Valley Cabins with succulent sedum in bands; 3) Ecospace sustainable garden studios with flat or mono-pitched mossy roofs requiring little maintenance; 4) Mobius Villa eco dwelling in China with a figure 8 design featuring a living green roof and solar panels. Green roofs provide benefits like reducing air pollution, managing stormwater, insulating buildings, and extending the life of roof materials.
The document discusses roof gardens and green roofs. It notes that roof gardens are intended to be used as gardens with thick soil layers and vegetation requiring maintenance, while green roofs use thin lightweight substrates and low-maintenance vegetation like moss and herbs. Both provide benefits like insulation, drainage of excess water, and protection of roof membranes. Geocomposite drain sheets provide optimal drainage and protection of roof membranes in roof gardens. Discharge capacities of roofing systems are outlined according to standards.
This document discusses types of roof gardens and considerations for creating one. It describes shallow, medium, and deep roof garden systems categorized by growth media depth and plant types. Key factors discussed include load capacity of the roof, drainage, maintenance access, choosing suitable plants for the sun/wind conditions, soil depth requirements, water availability, and other features like composting and seating areas. Load calculations and cross sections are provided.
This document provides a feasibility study for installing a green roof on Queen's University campus. It discusses the various types and benefits of green roofs, including energy savings, stormwater retention, and improving air quality and reducing the urban heat island effect. A case study is presented analyzing the financial feasibility of a hypothetical green roof that would cost $70,000 to install. The case study found the project would have a negative net present value but would reach a break-even point after 21 years. The study concludes that while this specific case may not be financially worthwhile, green roofs can provide environmental benefits and under different assumptions could potentially be a sound financial investment for Queen's University.
The document provides an overview of Green Roof Technology's publication "Green Instance", which highlights living infrastructure projects and technologies.
It begins by introducing the 'Sun-Root' living roof system, a new green roof technology that combines solar photovoltaic panels and modern green roofing. It then discusses Celebrity Cruises' award-winning "Lawn Club" onboard lawns and the David Kemp Hall green roof at Swarthmore College.
The document emphasizes the importance of integrating living systems into built environments in a way that seamlessly combines form and function. It highlights projects that best mimic natural ecosystems while serving their intended purposes efficiently.
Evergreen Roof Gardens is a green roofing company based in Sussex that specializes in green, brown, biodiverse, wildflower and meadow roofs. They can help with all aspects of green roofing projects from information to installation and maintenance. Green roofs lessen the impacts of climate change by absorbing carbon dioxide, increasing building insulation, and reducing stormwater runoff. Sedum roofs provide hardy, flowering plants that require little maintenance and have benefits such as thermal insulation, reduced carbon footprint, and aesthetic appeal. Brown and biodiverse roofs establish local ecosystems more cost effectively over time. Wildflower and meadow roofs bring long-lasting color and habitat for wildlife.
The document provides information on proper tree planting and establishment. It discusses the best times to plant, different types of planting stock like bare root, containerized, and balled and burlapped trees. It outlines proper handling, planting procedures, staking, watering, and mulching of newly planted trees. The key is to select the right tree species for the site, plant at the proper depth, maintain moisture levels, and remove stakes and guys after establishment.
This document discusses strategies for reducing urban heat islands through the use of trees and vegetation. It provides details on how trees and plants lower temperatures by providing shade and through evapotranspiration. The document outlines the many benefits of urban forestry initiatives, such as reduced energy usage, improved air quality, carbon storage, and economic benefits. It also discusses factors to consider for planting and maintenance, and provides resources for plant selection and evaluating costs and benefits.
Trees can be injured or killed by construction through root damage, soil compaction, physical damage to trunks and branches, and changes to soil grade. It is important for arborists to be involved in the planning stages of construction projects to preserve trees. Steps can be taken during construction like installing protective fencing and limiting access, compaction, and grade changes to preserve trees. Some treatment options after construction include pruning, cabling, irrigation, mulching, and aeration, but trees may still decline or die from damage. Regular monitoring is needed. The goal is to understand tree biology and take steps to minimize impacts during all stages of construction.
This document provides guidance for developing a green roof policy in Dublin. It defines different types of green roofs, including intensive, semi-intensive, and extensive green roofs. Extensive green roofs are the lightest type, using a shallow substrate layer and low-maintenance plants. The document examines benefits of green roofs like stormwater management, biodiversity and climate change adaptation. It reviews green roof policies in other cities and makes recommendations for Dublin, including developing incentives and awareness programs, and establishing an interdepartmental task force and green roof research.
The document discusses the benefits of building geodesic dome structures compared to traditional "A" frame homes. It states that domes are more sustainable, energy efficient, eco-friendly, and cost effective due to their strong structure which uses less material. Domes also have benefits such as being weather resistant, aesthetically pleasing, acoustic, and having high insulation values.
A brief overview about the green building strategy known as green roofing. This presentation was originally prepared for St. Louis regional educators who attended the 2014 Sustainability Institute for P12 Educators.
The document discusses green roofs and their implementation in Erbil City. It provides background on green roofs, their history and types. The document finds that Erbil has a low percentage of green areas at 6.5% compared to an international standard of 30%. It recommends implementing extensive and semi-intensive green roofs on individual building projects in Erbil to increase green space. On a city scale, the document suggests leaders support green roof laws and increase public awareness of their environmental benefits.
- Green roofs originated in Germany in the 1960s and 1970s as a way to replace natural spaces lost to rapid urbanization. They provided benefits like stormwater retention and temperature regulation.
- German research in the 1970s and standards established in the 1980s helped establish green roofs as an industry. By the 1990s there were an estimated 160 million square feet of green roofs in Germany, 95% of which were extensive lightweight sedum roofs.
- Proper installation requires following manufacturer specifications and industry standards. Key components include a waterproof membrane, filter fabric, drainage layer, growth medium, and plants. Safety, positive drainage, and compliance with local building codes are also important considerations.
This document discusses green roofs and their benefits. It begins by defining green roofs as roofs covered in vegetation rather than just a waterproof membrane. There are two main types of green roofs - extensive and intensive. Extensive green roofs are lighter and require less maintenance while intensive green roofs can support a wider variety of plants. Green roofs provide multiple benefits such as absorbing rainwater, providing insulation, creating wildlife habitats, and reducing the urban heat island effect. They can also improve air quality, increase energy efficiency, and extend the lifespan of roofs. The document examines these benefits in further detail.
David O Dowd's document discusses green roofs. It defines green roofs as roofs covered with organic material like moss or turf. There are benefits to using green roofs such as reducing heating/cooling costs, absorbing rainfall, and reducing CO2 emissions. The three main types of green roofs are intensive, semi-intensive, and extensive. Extensive green roofs, which use shallow soil and low-maintenance plants, are most applicable for homes. The document outlines the construction process for an extensive green roof and provides examples like Gary Neville's passive house with a full green roof.
The document discusses the benefits and components of green roofs. Green roofs can reduce urban heat, lower energy costs, improve air and water quality, and provide habitat. They are composed of a waterproof membrane, drainage layer, insulation, filter fabric, growing medium and plants. Extensive green roofs are lighter weight and have shallow growing media while intensive roofs support deeper media and larger plants. Proper planning is needed to coordinate a green roof installation with other construction trades and address scheduling, access, and potential damage from other work.
Green roofs, also known as eco-roofs or roof gardens, are gardens that are installed on top of buildings. There are two main types - extensive green roofs use sedum plants and only require 4 inches of soil, while intensive roofs can support a wider variety of plants and deeper soil. Green roofs provide multiple benefits such as reducing energy usage, absorbing stormwater, filtering air pollution, and creating wildlife habitats. They are made up of layers including a waterproof membrane, root barrier, drainage mat, and lightweight soil mix of aggregate and organic material to support plants. Green roofs are best installed on flat or low-sloped roofs but stabilization may be needed on steeper slopes.
This presentation gives a basic information about green roofing technology with easy English in a simple way. It has been used for conducting data about a study on "Assessing the awareness about green roofing technology and the effect of lecture on it. It is with minimum words and maximum content.
Role of plants in climate responsive buildingSurbhi Sharma
This document discusses the role of plants in climate responsive design and landscaping. It describes how macroclimate and microclimate affect plant selection and placement. Plants can be categorized as trees, shrubs, vines, ground covers, and turf grasses. Their placement is important for controlling solar radiation, wind, and humidity. Evergreens provide benefits in hot dry climates while deciduous plants are suitable for northern and southern exposures. Plant selection also depends on temperate, cool, hot-humid, or hot-arid climates. Overall, landscape design with native plants can help moderate temperatures and direct airflow to optimize building performance.
This document is to give an insight on green roofing system, comparing it to the traditional and modern roofing system and also enumerating some key advantages of the new or green system to the environment.
This document provides an overview and planning guide for Garden Roof® assemblies produced by Hydrotech. It discusses the benefits of green roofs, including reducing the urban heat island effect and stormwater runoff. It also outlines Hydrotech's approach to garden roof assemblies, which incorporates a monolithic membrane roof and proven green roof technologies. The document describes extensive, intensive, and lawn garden roof assembly types and lists their key components, such as growing media, drainage layers, and suitable plant types. Installation and maintenance considerations are also addressed.
This document discusses green roofs and their benefits. It provides examples of four different types of green roof designs: 1) Wave House with various plant varieties in a sine wave design; 2) Mill Valley Cabins with succulent sedum in bands; 3) Ecospace sustainable garden studios with flat or mono-pitched mossy roofs requiring little maintenance; 4) Mobius Villa eco dwelling in China with a figure 8 design featuring a living green roof and solar panels. Green roofs provide benefits like reducing air pollution, managing stormwater, insulating buildings, and extending the life of roof materials.
The document discusses roof gardens and green roofs. It notes that roof gardens are intended to be used as gardens with thick soil layers and vegetation requiring maintenance, while green roofs use thin lightweight substrates and low-maintenance vegetation like moss and herbs. Both provide benefits like insulation, drainage of excess water, and protection of roof membranes. Geocomposite drain sheets provide optimal drainage and protection of roof membranes in roof gardens. Discharge capacities of roofing systems are outlined according to standards.
This document discusses types of roof gardens and considerations for creating one. It describes shallow, medium, and deep roof garden systems categorized by growth media depth and plant types. Key factors discussed include load capacity of the roof, drainage, maintenance access, choosing suitable plants for the sun/wind conditions, soil depth requirements, water availability, and other features like composting and seating areas. Load calculations and cross sections are provided.
This document provides a feasibility study for installing a green roof on Queen's University campus. It discusses the various types and benefits of green roofs, including energy savings, stormwater retention, and improving air quality and reducing the urban heat island effect. A case study is presented analyzing the financial feasibility of a hypothetical green roof that would cost $70,000 to install. The case study found the project would have a negative net present value but would reach a break-even point after 21 years. The study concludes that while this specific case may not be financially worthwhile, green roofs can provide environmental benefits and under different assumptions could potentially be a sound financial investment for Queen's University.
The document provides an overview of Green Roof Technology's publication "Green Instance", which highlights living infrastructure projects and technologies.
It begins by introducing the 'Sun-Root' living roof system, a new green roof technology that combines solar photovoltaic panels and modern green roofing. It then discusses Celebrity Cruises' award-winning "Lawn Club" onboard lawns and the David Kemp Hall green roof at Swarthmore College.
The document emphasizes the importance of integrating living systems into built environments in a way that seamlessly combines form and function. It highlights projects that best mimic natural ecosystems while serving their intended purposes efficiently.
Evergreen Roof Gardens is a green roofing company based in Sussex that specializes in green, brown, biodiverse, wildflower and meadow roofs. They can help with all aspects of green roofing projects from information to installation and maintenance. Green roofs lessen the impacts of climate change by absorbing carbon dioxide, increasing building insulation, and reducing stormwater runoff. Sedum roofs provide hardy, flowering plants that require little maintenance and have benefits such as thermal insulation, reduced carbon footprint, and aesthetic appeal. Brown and biodiverse roofs establish local ecosystems more cost effectively over time. Wildflower and meadow roofs bring long-lasting color and habitat for wildlife.
The document provides information on proper tree planting and establishment. It discusses the best times to plant, different types of planting stock like bare root, containerized, and balled and burlapped trees. It outlines proper handling, planting procedures, staking, watering, and mulching of newly planted trees. The key is to select the right tree species for the site, plant at the proper depth, maintain moisture levels, and remove stakes and guys after establishment.
This document discusses strategies for reducing urban heat islands through the use of trees and vegetation. It provides details on how trees and plants lower temperatures by providing shade and through evapotranspiration. The document outlines the many benefits of urban forestry initiatives, such as reduced energy usage, improved air quality, carbon storage, and economic benefits. It also discusses factors to consider for planting and maintenance, and provides resources for plant selection and evaluating costs and benefits.
Trees can be injured or killed by construction through root damage, soil compaction, physical damage to trunks and branches, and changes to soil grade. It is important for arborists to be involved in the planning stages of construction projects to preserve trees. Steps can be taken during construction like installing protective fencing and limiting access, compaction, and grade changes to preserve trees. Some treatment options after construction include pruning, cabling, irrigation, mulching, and aeration, but trees may still decline or die from damage. Regular monitoring is needed. The goal is to understand tree biology and take steps to minimize impacts during all stages of construction.
This document provides guidance for developing a green roof policy in Dublin. It defines different types of green roofs, including intensive, semi-intensive, and extensive green roofs. Extensive green roofs are the lightest type, using a shallow substrate layer and low-maintenance plants. The document examines benefits of green roofs like stormwater management, biodiversity and climate change adaptation. It reviews green roof policies in other cities and makes recommendations for Dublin, including developing incentives and awareness programs, and establishing an interdepartmental task force and green roof research.
The document discusses the benefits of building geodesic dome structures compared to traditional "A" frame homes. It states that domes are more sustainable, energy efficient, eco-friendly, and cost effective due to their strong structure which uses less material. Domes also have benefits such as being weather resistant, aesthetically pleasing, acoustic, and having high insulation values.
Green roofs, also known as living roofs, allow plants to grow on building roofs. They provide environmental benefits like reducing stormwater runoff and the urban heat island effect. While initially costly, green roofs last longer than traditional roofs and provide savings over time. When planning a green roof, homeowners should consider their roof's slope, climate conditions, and structural ability to support additional weight. Green roofs have multiple layers, including a waterproof membrane, drainage layer, lightweight growing media, and drought-tolerant plants. Proper planning and installation are needed to ensure a successful green roof.
In this time of rising temperatures, abundant rain and socioeconomic imbalance, this seminar will suggest that green roofs are a powerful green building Best Management Practices (BMPs).
This presentation will outline the application, feasibility, benefits and challenges of green roofs in commercial application and put several widely debated questions into perspective: modular trays v. contiguous installations, upfront cost v. long-term investment, green roof v. other options, public access v. limited access, etc. Using local, national and international examples, she will explore green roof issues re: longevity, energy savings, stormwater management, maintenance, incentives and LEED points.
The three learning objectives are a) to understand green roof ROI for commercial buildings, b) to compare stormwater strategies of green roofs v underground cisterns and porous pavers and c) to compare green roofs to a solar roof or a white reflective roof.
Green roofs are a means to lowering the overall ambient temperature, reducing longterm costs on our buildings, sequestering CO2 and producing O2, improving the quality of life in our cities and boosting our green economy. Come learn more about green roofs at this seminar on May 7th.
The increase of peak and energy demand during the cooling and warming seasons is becoming a critical
issue, as well as air pollution and the intensification of the urban heat island effect. Green roof has been identified as a solution to mitigate the above-mentioned issues and implement principles of sustainable development in building features. There are many operational and environmental benefits of green roofs such as enhancement of buildings’ energy efficiency, improvement of storm water management, decrease of urban heat island effects, decline of air and noise pollutions, and increase of urban wild life habitats.
This paper discusses the current literature and evidence for the benefits of green roofs while highlighting the influences of green roofs on buildings’ energy efficiency. Researches conducted on the potential benefits of green roofs have proved that they can enhance energy performance of buildings in summer and winter as well as improving indoor air temperature.
This document provides an introductory guide to green walls in the UK. It discusses the benefits of green walls, which include improving air quality, increasing biodiversity, reducing the urban heat island effect, and providing aesthetic and well-being benefits to humans. It also outlines the basic types of green wall systems, including climbing façades that use plants to naturally grow over walls, and modular living walls that use hydroponic or soil-based systems to vertically cover structures in a more controlled manner.
The document discusses the history and benefits of green roofs. It describes how green roofs were used as far back as ancient Babylon but became more advanced in the 1970s. While Europe has embraced green roofs, the US is just starting to adopt the practice. The document outlines economic, social, and environmental benefits of green roofs, such as job creation, energy savings, improved air quality, stormwater management, and increased wildlife habitat. It concludes that while initial costs are high, green roofs provide measurable long-term benefits to building owners, communities, and the environment.
This document provides an overview of green building seminar report that discusses key elements of green buildings including siting, energy efficiency, passive solar design, renewable energy, and material efficiency. It describes various methods and materials used in green construction for sites, structures, floors, roofs, insulation, and more. Indoor environmental quality guidelines are also covered, focusing on durability, reusability, and reducing indoor pollutants. The conclusion emphasizes that green building design is important for environmental protection and benefits owners through reduced costs.
This document summarizes a research study that evaluated the stormwater and thermal performance of an extensive green roof system in Malaysia. The study found that the green roof reduced peak stormwater discharge by up to 26% compared to a concrete tile roof. It also increased stormwater pH levels and improved water quality. However, the green roof's ability to reduce discharge decreased for intense rainfall events. Indoor temperatures near the green roof were also up to 5% lower after installation. The study aims to provide data to help develop green roof design guidelines for Malaysia's tropical climate.
Question 4 (5 pts) Timber elements will be used as floor joist in the.pdfaroramobiles1
Question 4 (5 pts) Timber elements will be used as floor joist in the construction of a skywalk in
Phoenix Arizona. Kiln-dried lumber will be used as a construction material. a) Which service
design factor must you take into design consideration? b) How will it affect the flexural
properties of the timber joist once in service? c) Explain why by describing the microstructural
properties responsible for that specific mechanical behavior? d) If the same structure was built,
using the same material, along the New Jersey shore line; would you change your design
parameters? Explain why
Solution
Wood drying (also seasoning lumber or wood seasoning) reduces the moisture content of wood
before its use. When the drying is done in a kiln, the product is known as kiln-dried timber or
lumber, whereas air drying is the more traditional method.
A. Use of near-minimum values for conversion factors making further reduction for unforeseen
conditions to indicate near-minimum factor of safety of 1-1/4 to 1-1/2; factors in strength and use
can be combined into one frequency distribution that shows range of true factor of safety; most
probable values of factor of safety in timber design are in range of 2 to 2-1/2.
B.When wood fiber is exposed to significant heat, its flexural strength decreases. It has long been
known that prolonged heating at temperatures over 66°C (150°F) can cause a permanent loss in
strength.
Moisture content (MC) has an important influence on the physical and mechanical properties of
wood. This has to be taken into account when using timber for structural purposes; in particular,
a correct estimation of the modulus of elasticity (E) is not only important for the key role that
this parameter plays in design calculations, but also because it is a property that can be measured
non-destructively and used to predict the quality of the material and, thus, to strength grade it.An
increment of 27.7 % in bending strength from green to dry state was also calculated.
C.According to the literature, drying has a distinct effect on wood microstructure, properties and
impregnation.Bailey (1913) studied the penetration of gases and preservatives in dried wood. In
addition to the impor-tant pathways of penetration such as parenchyma cells and pits, he
discusses the existence of “narrow micro- scopical slits”, i.e. micro checks in the wood cell wall
caused by drying.
The industrial progressive and conventional batch kiln drying procedures used had only minor
effects on the microstructure of Scots pine wood. The high tempera- ture kiln drying (at 115 °C)
can partly damage the aper-tures of some bordered pits, provoke nano (10–20 nm) and micro
checks (1–2 µm).There is no critical reduction of the impact bending strength, hardness and
MOE of the dried untreated wood regardless the drying method. The progressive and
conventional batch kiln drying reduce significantly MOR while the high temperature drying has
no apparent effect. Impregnation with Tanalith E and co.
Green roofs, external and internal walls - Hulfarin Keren & Nbewany SallyTagit Klimor
This document provides an introduction and literature review on green roofs and walls. It begins with background on the need for more sustainable building practices given issues like the urban heat island effect. It then defines green roofs and walls, describing their benefits such as improved thermal regulation of buildings, reduced air and water pollution, and decreased energy demands. The document reviews literature on green roof retrofitting around the world and their performance in different climates. It presents case studies and a discussion of the topic, ultimately concluding that green roofs and walls can help address sustainability challenges in cities if their long term environmental and economic benefits are considered.
This document discusses green roofs, which are roofs that are fitted with vegetation. It outlines several environmental problems such as air pollution and flooding. It then defines green roofs and describes the main types: extensive, intensive, and semi-intensive. Benefits of green roofs include reducing air pollution by absorbing minerals and producing oxygen, attenuating storm water runoff, providing insulation to reduce energy costs, and creating a cooler environment. The document also gives an example of a green roof on an apartment building in Parnell Street and envisions greater use and research on green roofs in the future.
This document provides information on green roofs and their ability to reduce urban heat islands. It acknowledges that roofs make up 20-25% of land cover in major US cities, presenting opportunities for green roof installation. Green roofs work by shading roof surfaces and through evapotranspiration of vegetation, which cools the air. They come in extensive and intensive varieties. Benefits include reduced energy costs, stormwater management and increased roof lifespan, while costs have come down in recent decades. The document provides details on design considerations and gives an overview of green roof initiatives and resources for further research.
46_Badiu-Bratucu_2 TYPES OF INFRASTRUCTURE USED FOR GROWING PLANTS INEDUARD C BADIU
This document discusses types of infrastructure used for growing plants in greenhouses located on building roofs. It describes how greenhouses on roofs can help reduce pollution and carbon dioxide levels while providing a quiet oasis. There are several types of roof structures that can support different kinds of plants, from shallow beds for grass to deeper structures for trees and shrubs. When designing greenhouses for roofs, considerations include withstanding high winds, reducing weight, and complying with regulations regarding the building structure and permits. Common materials used for greenhouse roofs are glass, plastic sheeting, polycarbonate panels, and fiberglass, with benefits and drawbacks to each.
Construction of an Elevated Garden - The Basics of Growing Green RoofsFarrah85p
This document provides an overview of green roofs, including their history and benefits. It discusses the different types of green roofs - extensive, intensive, and semi-intensive - and the key components of a green roof system, including a drainage layer, water retention product, root barrier, and growing medium. The document also summarizes a case study of a green roof installed at the National Research Council of Canada that demonstrated benefits like reducing urban heat and stormwater runoff.
Green roofs provide numerous advantages including:
1) Visual amenities like additional recreational space and more attractive appearances.
2) Economic benefits such as prolonged roof membrane lifespan up to 20 years, potential food production savings, and reduced heating/cooling costs.
3) Environmental advantages including increased biodiversity as habitats, improved stormwater management, better air quality from captured particles, lowered urban heat islands, reduced noise pollution, and decreased fire risk.
This document provides an overview of skyrise greenery and sustainable high-rise gardens. It discusses the evolution of skyrise greening from an emphasis on aesthetics to recognizing its environmental and wellness benefits. It describes different forms of skyrise greenery like vertical greenery, roof gardens, and green roofs. The document outlines considerations for skyrise greenery projects including structural, safety, maintenance and planting factors. Examples of skyrise greenery initiatives in Singapore are also highlighted.
Similar to Rasmussen Final+Paper+Green+Roofing (20)
4. GREEN ROOFING 4
Green Roofing
The rise of environmentally-focused and sustainable solutions has brought planners back
to an ancient solution to better commune with nature while creating a more pleasant and efficient
urban environment. Green roofing has been firmly entrenched in European cities and is gaining
popularity in businesses, cities and even personal homes here in the United States
(Environmental Protection Agency, 2013). They are more pleasant to look at, reduce water
runoff, and reduce heat accumulation. This paper will discuss how the green roof works, how it
is constructed, what it costs, long-term issues and feasibility.
Description of a Green Roof
A green roof is a roof that is deliberately constructed to support vegetation. A green
roofing is not a new science, dating back to 4000 B.C. when sacred places were constructed with
vegetated roofs, like sod, over elevated surfaces. (Weiler & Scholz-Barth, 2009). The goal of a
green roof is to reduce pollution through mitigating stormwater runoff by up to 80 percent
(Environmental Science in Forestry, n.d.), reduce the urban heat island effect, filter pollutants,
reduce carbon dioxide, and to maximize urban land utilization. Additionally, the added beauty of
a well-kept green roof is much more attractive than a tar or membrane covered one. Carson
reminded us in “Silent Spring”, that we should strive to live along-side of nature rather than to
control it (Carson, 1962).
Construction
There have been several approaches to green roof construction. All of which necessitate
professional design and structural analysis. Initial costs generally start around $10 per square
5. GREEN ROOFING 5
foot for a simple extensive roof, and $25 per square foot with intensive roofs (Environmental
Protection Agency, 2013). This is significantly more than the typical $1.25 per square foot of a
normal built-up roof. This initial cost can turn away many prospective builders.
The basic construction typically includes a layer of waterproofing, drainage mats, root
barriers, engineered planting material, and plants. These plants vary with the location, depth of
the planting material, and overall use intent of the roof (Environmental Science in Forestry, n.d.).
There are two basic types of green roofs, extensive and intensive (Dvorak, 2015). The
lower maintenance extensive roofs are categorized as having a shallow growing medium and
generally are suited for succulent plant types (Dvorak, 2015), these are sometimes called a living
green roof. Intensive roofs also have a biodiverse variation of plants instead of the succulents,
any plants in this type of roof must be hardy and drought-resistant. Both types of roof will have
the following basic components: vegetation, growing medium, drainage layer, root barrier, and a
waterproofing membrane (Environmental Protection Agency, 2013).
1. Extensive Roof. Extensive roofs have about six to eight inches of growing
medium and will assist in stormwater management (Weiler & Scholz-Barth, 2009). The
resulting excess runoff can be stored in cisterns for use to water the roofs in extended
drought periods (Birch & Wachter, S., 2008, p. 177). The thinner profile of a living
green roof generally runs between 12 to 15 pounds per square foot (Environmental
Protection Agency, 2013).
Each extensive roof will have specific design requirements that necessitates a
structural analysis. Because the weight is comparable to a stone ballast roof with the
waterproof protective membrane, there is usually no structural upgrade (Weiler &
Scholz-Barth, 2009). Generally, there is not many additional costs resulting from needed
6. GREEN ROOFING 6
increased structural support for new buildings. This can make a case for the planner to
provide a greater visual amenity as well as improved environmental quality.
The extensive roof can be used instead of a more conventional stormwater
management method as the rain filters through the heat tolerant plants and erosion control
mediums on top of the soil, through the planting media to be taken in by the roots of the
plant. There is a drainage mat that holds in the water under the soil and excess water
funnels onto the waterproofing material under the drainage mat and into overflow pipes
that connect to drain water systems. Under the waterproofing material there is an
additional layer of insulation over the roof deck. (Environmental Science in Forestry,
n.d.). One obvious benefit of this is that water evaporates from the planting medium and
plants which helps to regulate the surface temperature of the roof. Below is a picture
depicting a common extensive green roof and its different layers.
2. Intensive Roof. The intensive type of roof may include rooftop gardens and a
greater variety of plants. These require more maintenance and usually have a deeper
growing medium (Dvorak, 2015). These are also referred to as landscape over structure
and can be used as an accessible green garden or open space (Weiler & Scholz-Barth,
2009). The depth of the growing medium is eight inches up to several feet deep. The
(Dvorak,2015)
Extensive Green Roof
7. GREEN ROOFING 7
weight of this type of roof can run 50lbs or more (Environmental Protection Agency,
2013). This type of system requires more complex planning to ensure that the roof
structure can support the additional weight. An irrigation system may be necessary
during drought times or dryer periods of the year depending on vegetation requirements.
Layers
As mentioned before, the basic layers of construction starting at the top include:
vegetation, drainage, root barrier, waterproofing membrane, and growing medium. There are
also others that are used like a cover board, thermal insulation, vapor barriers, and other
structural supports.
1. Vegetation. Vegetation types will vary depending on the climate, design and use,
available sunlight, irrigation requirements and anticipated rainfall. The EPA
recommends maintenance that consists of weeding every month when the roof is
installed. According to this federal guideline, this weeding may be necessary every
month or at least quarterly for the first two years and every year thereafter
(Weiler & Scholz-Barth, 2009)
Intensive Green Roof
8. GREEN ROOFING 8
(Environmental Protection Agency, 2013). Additional requirements for green roof
maintenance include fertilizing, replanting, and depending on the plants, irrigation.
a. Extensive green roof. Vegetation for extensive green rooftops is generally a
succulent or drought and wind resistant plants (Werthmann, 2007) and tend to
be shallow rooting perennials (Environmental Protection Agency, 2013).
These plants generally need to have a high water content to be more fire
resistant.
b. Intensive green roof. The deeper growing media allows bushes, shrubs, and
trees. These usually require additional irrigation to be added into the design
(Environmental Protection Agency, 2013).
2. Growing Medium. The growing medium may be soil or may be a specifically
engineered medium that consists of up to 80% inorganic material and 20% organic
topsoil. This will normally be designed to last as long as the roof and will be the lightest
weight that can support the intended plant life (Environmental Protection Agency, 2013).
The porosity, or space made up by air, of the medium is important to take into
consideration (Weiler & Scholz-Barth, 2009). The size of particles within the medium
will dictate this porosity. Sand and gravel are larger and have larger spaces, while
colloids like clay have smaller spaces. The larger the space, the quicker the water will
run through it. One note about colloids, is that they are harder to get wet, but once wet,
they will retain water longer than sands or gravel (Weiler & Scholz-Barth, 2009).
There is often a filter membrane installed over the growing medium that consists
of a geotextile to keep the growing material from washing away and cause clogging of
the drainage systems. (Environmental Protection Agency, 2013)
9. GREEN ROOFING 9
3. Drainage Layer. This layer allows excess water drain from the growing
medium and prevents overloading the green roof (Environmental Protection Agency,
2013). This also allows a layer of air to get into the growing medium to create a healthier
soil. These can be egg crate like material that allows for water storage. Intensive and
extensive may both also have a cistern to collect water for future irrigation purposes
(Weiler & Scholz-Barth, 2009).
4. Root Barrier. The root barrier layer provides a separation and protection for the
waterproofing membrane and other lower layers from leaks caused by aggressive root
systems (Environmental Protection Agency, 2013).
a. IRMAs. Under the root barrier, there are often inverted roof membrane
assemblies (IRMAs), which are located above the waterproofing membrane
that are designed to protect the membrane and provide additional insulation.
These can be made of stones or concrete pavers. These are often used when
retrofitting an existing stone ballast roof (Environmental Protection Agency,
2013).
5. Waterproofing Membrane. A layer of impermeable material to prevent water
damage to the structure of the building. The waterproof membranes used in green roofs
are generally more durable and thicker than the ones used in conventional roofing
(Environmental Protection Agency, 2013). Some green roofs may skimp on the root
barrier and use this instead.
6. Cover Board. This is not always used but is a semi-rigid board that protects the
waterproofing membrane and creates separation and additional support (Environmental
Protection Agency, 2013).
10. GREEN ROOFING 10
7. Thermal Insulation. This is another layer that is not always used, but is installed
either above or below the waterproofing membrane and provide additional insulation to
the required insulation of the building. Note: green roofing is not an accepted substitute
for traditional insulation (Weiler & Scholz-Barth, 2009).
8. Vapor Barrier. This layer is the same as the vapor barriers on the walls of a
house or in a basement. It simply is either a foil or plastic sheet to prevent moisture to
pass through. This is not always used, but is a good idea.
9. Structural Supports. Additional structural supports are often necessary to
support the additional weight of the green roof. This is especially the case in intensive
roofing systems or if a roof is retrofitted with a green roof (Weiler & Scholz-Barth,
2009).
Hydrologic Cycle
The hydrologic cycle is a description of how water is constantly exchanged between the
atmosphere and the ground as precipitation and evapotranspiration. This is important to
understand as it connects how the green roof helps with the heat island effect and the stormwater
drainage problems.
(COTF.edu, 2004)
Hydrologic Cycle
11. GREEN ROOFING 11
There are five primary components of the hydrologic cycle. They are:
1. Precipitation. Defined as “Process of water in the atmosphere returning to the
Earth’s surface in liquid or solid form (Cech, 2010, p. 27)” (rain or snow fall). It moves
as dictated by the surface characteristics on which the precipitation falls and on the
duration and intensity of the storm,
2. Runoff. Defined as “Amount of water that flows along the land surface after a
storm event or from melting snow in the spring (Cech, 2010, p. 32)”. Water can run as
either overland flow or interflow toward a lake, river, or stream. Overland flow indicates
that the water travels above ground (surface). This type of flow occurs when there are
intense, short-duration rains or when there is an impervious surface like a rooftop, or
concrete. Interflow is water that infiltrates the soil and moves laterally just below the
surface (subsurface) of the ground in the soil toward its target body of water. This type
of flow occurs when there is a steady light rain and the ground surface is at least partially
pervious to water (Cech, 2010, pp. 77-78).
3. Surface and groundwater storage. Groundwater is defined as “Water contained
in interconnected pores of geologic material below the land surface (Cech, 2010, p.
105)”. In other words, it is water beneath the surface of the earth which saturates the
pores and fractures of sand, and rock formations into aquifers. Surface water is the
rivers, lakes, oceans above the soil.
4. Evaporation/transpiration. Defined as the loss of water to the atmosphere when
liquid water is turned into vapor. Evaporation happens off of the ground and
transpiration happens when plants release water through their leaves during
photosynthesis (COTF.edu, 2004).
(COTF.edu, 2004)
12. GREEN ROOFING 12
5. Condensation. Condensation turns water vapor into liquid. This condenses into
clouds and become precipitation (COTF.edu, 2004).
Stormwater
Stormwater is basically the water that is not intercepted by plants or soil (Weiler &
Scholz-Barth, 2009). Stormwater management is an old concept. As long as there have been
dwellings, humans have run into the issue of stormwater runoff. The current standard of roofing
and street construction that almost every city in a developed country has consists of an
impervious layer that sheds one hundred percent of the water and shunts it into some sort of
gutter or sewer system and it is removed from the immediate area. The result is that planners
have designed an unhealthy system that shunts the hydrological cycle and causes serious impacts
on both volume and water quality in watersheds.
Another problem is that these surfaces are impermeable and designed to shed all of the
water. It goes into the storm drain and stormwater management systems. The increasing amount
of roofs, parking lots and other paved areas causes an ever increasing amount of water that is
overwhelming the structure of most cities sewage or stormwater systems (Werthmann, 2007).
There are cities that report losing enough stormwater annually to provide over 3.6 million
people with enough water to cover their annual home needs (see Table 2) (Weiler & Scholz-
Barth, 2009). To combat this, many planners are striving to find green and sustainable ways to
reintroduce nature into cities to correct these problems.
13. GREEN ROOFING 13
Computing Water Discharge
As mentioned before, stormwater discharge has become a prevalent issue for many cities.
The goal of stormwater management is to maximize water infiltration into the soils and ensure
that surface and subsurface runoff is controlled to minimize erosion damage and flow volume.
By maximizing soil infiltration, it maximizes use for plants.
There are many factors of water movement that need to be taken into consideration. The
movement of the water through the soil medium, the gradient of the slope and the peak runoff
rate are all important factors to consider when designing a green roof to assist in stormwater
retention and mitigation.
The natural movement of water through the soil is an important place to start. The
standard way that hydrologists calculate how water discharge moves through a medium is to use
Darcy’s Law. Darcy’s Law explains, using mathematical equations, how water discharge moves
through a bed of sand. The equation is (Cech, 2010, pp. 123-124):
(Environmental Science in Forestry, n.d.)
Green Roof as Part of
Stormwater Management Plan
14. GREEN ROOFING 14
𝑞 = 𝐾𝑖
Where 𝑞 = specific discharge per unit area
𝐾 = hydraulic conductivity of the medium
𝑖 = hydraulic gradient
It figures out that the specific discharge per unit area equals the hydraulic conductivity of
the medium multiplied by the hydraulic gradient (Cech, 2010, pp123-124). The hydraulic
conductivity can be described as the actual measurement of rate of flow through a porus material
like soil (Cech, 2010, p. 122).
Once this specific discharge is determined, it is then divided by the porosity of the
aquifer. The result is the actual discharge, which will be a higher number than the specific
discharge because the water can only move through porous space and not the entire cross section
of the aquifer (Cech, 2010, pp126). The size of the particles in the aquifer determine the volume
of water: smaller grains equals less water volume; larger grains equals more volume. In the case
of most green roofs, the soil material is a specially engineered material that is light in weight and
porous (Werthmann, 2007).
Determining Flow
Determining what the gradient is important to stormwater management as well as
determining the specific discharge as it feeds into the overall flow calculations. The ground
plane (slope) of the roof or gradient will dictate the pull of gravity on the water. The more
gradual or smaller the slope and more permeable the soil is will increase the stormwater
retention. Conversely, the steeper the slope, the quicker the stormwater will move out of the
roof, decreasing the amount of retained water.
15. GREEN ROOFING 15
The hydraulic gradient formula looks like this (Cech, 2010, p. 122):
𝑖 = 𝑑ℎ/𝑑𝑙
Where 𝑖 = ℎ𝑦𝑑𝑟𝑎𝑢𝑙𝑖𝑐 𝑔𝑟𝑎𝑑𝑖𝑒𝑛𝑡
𝑑ℎ = 𝑐ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝑡𝑤𝑜 𝑝𝑜𝑖𝑛𝑡𝑠 𝑎𝑡 𝑡ℎ𝑒 𝑡𝑜𝑝 𝑜𝑓 𝑡ℎ𝑒 𝑔𝑟𝑎𝑑𝑒
𝑑𝑙 = 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝑡ℎ𝑒 𝑡𝑤𝑜 𝑝𝑜𝑖𝑛𝑡𝑠
This is important as the rate that the water infiltrates growing mediums or becomes runoff
is dictated by the gravity, slope, and permeability of the surface.
Peak Runoff Rate
Once the discharge rate of the soil and the gradient slope are understood, the maximum
amount of water that the soil medium is designed to handle must be understood to determine if it
is the correct blend in the soil mixture. Determining what the peak runoff rate (PRR) is
important to understand as it represents the maximum cubic feet per second that must be
managed (Weiler & Scholz-Barth, 2009). This number is based off of the theory that the PRR of
the area equals the intensity of rainfall multiplied by the coefficient that represents the variables
(see Table 1), characteristics and size of the drainage area (Weiler & Scholz-Barth, 2009). This
measurement can be adjusted to compute the peak runoff rate (in cubic feet per second) with the
rational method, this formula is used (Weiler & Scholz-Barth, 2009):
𝑄 = 𝐶𝐼𝐴
Where 𝑄 = 𝑝𝑒𝑎𝑘 𝑟𝑢𝑛𝑜𝑓𝑓 𝑟𝑎𝑡𝑒 ( 𝑐𝑢𝑏𝑖𝑐 𝑓𝑒𝑒𝑡 𝑝𝑒𝑟 𝑠𝑒𝑐𝑜𝑛𝑑)
𝐶 = 𝑟𝑢𝑛𝑜𝑓𝑓 𝑐𝑜𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑡
Where 0 is completely pervious and allows no runoff and 1 is completely impervious. (The
more natural the soil, the smaller the coefficient.)
16. GREEN ROOFING 16
𝐼 = 𝑟𝑎𝑖𝑛𝑓𝑎𝑙𝑙 𝑖𝑛𝑡𝑒𝑛𝑠𝑖𝑡𝑦 (𝑖𝑛𝑐ℎ𝑒𝑠 𝑝𝑒𝑟 ℎ𝑜𝑢𝑟)
This indicates the intended storm frequency and how long the water will be concentrated in the
drainage medium
𝐴 = 𝐴𝑟𝑒𝑎 𝑖𝑛 𝑎𝑐𝑟𝑒𝑠 𝑜𝑓 𝑑𝑟𝑎𝑖𝑛𝑎𝑔𝑒 𝑎𝑟𝑒𝑎
What is immediately apparent by looking at C, the runoff coefficient, is that when the
other variables are held equal, peak flows are less when the surfaces consist of natural soils that
allow infiltration.
Now that it has been established how to build a green roof, the hydrologic cycle, and the
way that they can be included into the stormwater management plan, the discussion will move to
how it fits into ecology of an urban environment.
Ecology
Ecology from an urban standpoint has issues that can be addressed by the implementation
of green roofs. The impervious surfaces have created an imbalance in stormwater retention and
do not allow the natural processes to cool off solar energy. The result is that large cities have
created an environment that does not retain water, is not biodiverse, and average temperatures
continually increase due to a “heat island effect” caused by large portions of an urban area being
covered with impervious materials.
By installing green roofs on only 5 percent of a city’s rooftops, it can reduce overall air
temperatures between two and four degrees Fahrenheit (Birch & Wachter, S., 2008, p. 81). The
temperature of a green roof depends on the composition, moisture content of the growing
medium, solar exposure. The green roof stays cooler because of the shading and
evapotranspiration (Environmental Protection Agency, 2013). The secondary effects of this will
17. GREEN ROOFING 17
include dropping the need for electricity to air condition buildings and increasing urban water
reserves. There has been a broad acceptance of these benefits and many initiatives have been
adopted by cities across America and in Canada.
Green Roof Initiatives
Many cities and communities have recognized the benefits of green roofing. For
instance, Chicago recognized these effects and in 2000, it embraced a greening initiative and has
implemented ordinances to install green roofs to reduce its stormwater runoff (Birch & Wachter,
S., 2008, p. 92).
Seattle is also a leader with their “Seattle Green Factor”. This initiative requires 30%
vegetation coverage for any new developments within their neighborhood or commercial
districts. This initiative focuses on decreasing the negative environmental impacts that have
resulted through the increased development. The remediation envisions a high-quality urban
landscape that provides increased biodiversity and other environmental benefits that are
mentioned here. This is a turning point initiative as it recognizes the fact that the urban landscape
is an important part of a functioning of the city, and not just there for aesthetic value (Birch &
Wachter, S., 2008).
Other cities that have implemented stormwater ordinances that include green roofs are
Portland, and Philadelphia. These cities allow tax breaks for some of their programs. These
programs save millions of dollars in stormwater management and storm drain system upgrades to
keep up with the runoff from the always increasing impervious surface area that comes when
buildings or streets are built (Weiler & Scholz-Barth, 2009).
18. GREEN ROOFING 18
There are many advantages from the additional vegetation. It will serve as a dust
collector and air cleaner. The vegetation will decrease noise pollution and increase habitat for
animals, birds, and insects. People have been fleeing the city to get to a pleasant place to live
and raise their families. This is the one of the main causes of urban sprawl (Birch & Wachter, S.,
2008). Greener spaces will increase the desire for people to live and work in the city. All of
these points will lead to a better ecology for the urban environment. When many cities
accomplish these goals, it will start reducing the global heat island effects through evaporative
cooling and water retention. While green roofs alone will not save the world, they can make a
significant contribution to reducing climate change.
Costs
As mentioned in the construction section, there are different types of green roofs.
Depending on the components, growing medium, membrane quality, drainage system, types and
quantity of plants, and use, the costs will vary greatly. An extensive roof will start around $5-
$10 per square foot and an intensive roof cost can start around $25-$40 per square foot
(Environmental Protection Agency, 2013). These costs can go up exponentially as different
options are included. The benefits of green roofing is that it will last up to 20 years more than a
conventional roof.
The annualized replacement costs for an extensive roof in the Los Angeles area is
reported to average between $1.03-1.66 per square foot (Environmental Protection Agency,
2013). The annualized costs for a conventional roof ran between $0.51-$1.74 per square foot
(Environmental Protection Agency, 2013). Annualized maintenance costs for either type of roof
ran about $0.75-$1.74 per square foot (Environmental Protection Agency, 2013). An important
19. GREEN ROOFING 19
note is that the intensive roof’s maintenance cost will be stable throughout its lifetime, while an
extensive roof‘s maintenance cost will drop once the roof is mature. These long-term benefits
will provide savings on a roof that is more enjoyable and longer lasting.
Savings
Specific savings vary depending on many variables including size of roof, use of the roof,
insulation, and other environmental considerations. There have been many success stories. For
instance, Chicago reports that their city hall saves about $3,600 annually in energy savings and
9,270 kWh from cooling savings and about 740 million Btu of saved heating (Environmental
Protection Agency, 2013).
Along with these direct and immediate savings, it reduces the need for constant upgrades
to sewage systems. Another benefit is that green roofs are more durable, often lasting about 20
years longer than a similar conventional roof (Werthmann, 2007).
Many cities are offering tax-breaks or remitting taxes altogether. This often will cover
the difference between the conventional roof and the green roof’s initial installation costs (Weiler
& Scholz-Barth, 2009). This will increase the savings benefits immediately.
Benefits
There are many benefits to green roofing. They include:
Reducing surface temperatures that allow the buildings to stay cooler
o Accomplished through evapotranspiraion and shading. Other factors that
influence this include: rooftop composition, geographic location, moisture
content, and solar exposure (Environmental Protection Agency, 2013)
20. GREEN ROOFING 20
o Lower temperatures low the formation of ground-level ozone-care must be
taken to ensure that volatile organic compound (VOC) producing plants
are avoided as these additional VOCs will add to ozone production
Creating green spaces to improve quality of life, citizen health, desirability of
urban living and working, increasing property values.
Introducing more mitigation factors for cleaner air, dust and particulate matter
(PM) filtering, and carbon dioxide reduction
o The EPA reports that a 1,000 square foot green roof can filter 40lbs of PM
annually- about the amount of CO2 emitted from 15 passenger cars
annually (Environmental Protection Agency, 2013)
Reducing energy needs by requiring air conditioners to run less
Lower long-term costs and increased durability; lowering annual costs as a roof
matures (Environmental Protection Agency, 2013)
Increased habitat for birds, animals, and insects (increased biodiversity)
Reduced stormwater runoff. Portland reported a 70% reduction over 15 months
(Environmental Protection Agency, 2013)
o Reduced costs of updating for increased flow resulting from increased
impervious construction and roofing
o Reduced erosion
o Reduced non-point source pollution
o Increased groundwater retention; the deeper and more extensive the green
roof, the more it collects
21. GREEN ROOFING 21
o Reduces peak runoff rates by up to 95% into stormwater systems during
intense storms (Environmental Protection Agency, 2013)
Will reduce noise
Can be used as a food producing source
Liabilities
There are a few negative aspects of green roofing that include:
Increased up front expenses
Required maintenance
Fire hazard if not kept up
Additional considerations that need to be calculated prior to installation or
building
o Each site needs to be evaluated separately
o Many disciplines of professionals need to be consulted prior to building.
These professionals will need to determine the infrastructural needs to
support the building and site program. They include:
Building architects
Landscape architects
Structural engineers
Civil engineers to calculate water retention capacity
Mechanical engineers to determine:
mass of the growing media and/or vegetation mass at
various moisture levels
22. GREEN ROOFING 22
how to incorporate the insulating values of the green roof
into the sizing of heating, cooling, and air-conditioning
systems.
Liability Mitigation
The liabilities are far outweighed by the benefits. The upfront costs can be offset by
municipal tax breaks or other incentives. Even if they are not, the long-term benefits and longer
life of the green roof offset this and surpass it as a long-term investment. The benefit to the
municipal stormwater makes this an effort worth investing in for cities.
The maintenance issues of having to water it regularly or weed the roof are something
that has to be a conscious decision to live with and plan for.
The fire hazards can be mitigated by using water heavy plants like succulents and
additional irrigation. Prior planning of grasses or other vegetation will take this into
consideration and can be alleviated by proper plant choice.
The technical considerations and professional requirements are something that are
included into the long-term costs. Cutting corners at the initial building phase will cause huge
issues later.
Conclusion
The green roofing initiative has been proven across Europe and in many cities across
North America. It has proven to lower the urban heat index, increase air quality, mitigate
stormwater runoff, and increase energy efficiencies while increasing urban beauty, providing
some biodiversity, lowering city noise, and improving the health of the citizens. Green roofs are
23. GREEN ROOFING 23
a sustainable environmental initiative that can assist in returning nature to cities in a way that
benefits consumers and businesses alike. The long-term financial benefits in the form of reduced
stormwater management systems will make this a feasible initiative for many cities.
24. GREEN ROOFING 24
References
Birch, E., & Wachter, S. (2008). City in the Twenty-First Century : Growing Greener Cities :
Urban Sustainability in the Twenty-first Century. University of Pennsylvania Press.
Retrieved February 18, 2015, from
http://site.ebrary.com/lib/apus/reader.action?docID=10641556
Carson, R. (1962). Silent Spring (40th Anniversary Edition ed.). New York, NY: Houghton
Mifflin Harcourt Publishing Company. Retrieved February 14, 2015
Cech. (2010). Principles of Water Resources/History, Development, Management, and Policy
(3rd ed.). Hoboken, NJ: John Wiley & Sons, Inc. doi: ISBN: 978-0-470-13631-7.
COTF.edu. (2004). Water Cycle. Retrieved February 20, 2015, from
http://www.cotf.edu/ete/modules/msese/earthsysflr/water.html
Dvorak, B. (2015). Green Roofs. Retrieved February 20, 2015, from Soil Science Society of
America: https://www.soils.org/discover-soils/soils-in-the-city/green-roofs
Environmental Protection Agency. (2013). Green Roof. Retrieved February 15, 2015, from Heat
Island Effect: http://www.epa.gov/heatisland/mitigation/greenroofs.htm
Environmental Science in Forestry. (n.d.). ESF Green Roof: Sustainability in Action. Retrieved
February 15, 2015, from http://www.esf.edu/sustainability/action/greenroof.htm
Weiler, S., & Scholz-Barth, K. (2009). Green Roof Systems: A Guide to the Planning, Design and
Construction of Landscapes Over Structure. John Wiley & Sons. Retrieved February 15,
2015, from
http://library.books24x7.com.ezproxy1.apus.edu/assetviewer.aspx?bookid=29517&chunk
id=999218983
25. GREEN ROOFING 25
Werthmann, C. (2007). Green Roof- A Case Study. Washington, D.C.: Princeton Architectural
Press. doi:SB419.5.W47 2007eb
26. GREEN ROOFING 26
Tables
Table 1
Runoff Coefficient
Runoff Coefficient (Weiler & Scholz-Barth, 2009)
Ground Cover or Land Use Runoff Coefficient (C)
Forests "0.05-0.25"
Lawns "0.10-0.35"
Cultivatedland "0.08-0.41"
Meadow "0.10-0.50"
Parks,cemeteries "0.10-0.30"
Unimprovedareas "0.10-0.30"
Pasture "0.12-0.62"
Pasture withmoderate grazing "0.10-0.30"
Bare earth "0.20-0.90"
Steepgrassedarea(2:1 slope) "0.50-0.70"
Residential areas "0.30-0.75"
Flatresidential areas,30%impervious "0.30-0.50"
Flatresidential areas,70% impervious "0.50-0.80"
Businessareas "0.50-0.95"
Flatcommercial/industrial area,90%impervious "0.50-0.90"
Asphaltorconcrete streets "0.70-0.95"
Brick streets "0.70-0.85"
Roofs "0.75-0.95"
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as a subscriptionbenefitof Books24x7, http://www.books24x7.com/,andisgovernedby
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27. GREEN ROOFING 27
Table 2
Annual Runoff Water Loss
Table 2
Annual Runoff Water Loss (Weiler & Scholz-Barth, 2009)
MetropolitanArea
Water Loss (billion
gallons/year)
Atlanta,Georgia "56.9-132.8"
Boston,Massachusetts "43.9-102.5"
Philadelphia,Pennsylvania "25.3-59"
Washington,D.C. "23.8-55.6"
Nashville,Tennessee "17.3-40.5"
Charlotte,NorthCarolina "13.5-31.5"
Pittsburgh,Pennsylvania "13.5-31.5"
Houston,Texas "12.8-29.8"
Greensville,SouthCarolina "12.7-29.5"
Seattle,Washington "10.5-24.6"
Chicago,Illinois "10.2-23.7"
Raleigh-Durham/ChapelHill,NorthCarolina "9.4-21.9"
Orlando,Florida "9.2-21.5"
Minneapolis/St.Paul,Minnesota "9.0-21.1"
Detroit,Michigan "7.8-18.2"
Tampa, Florida "7.3-17"
Greensboro,NorthCarolina "6.7-15.7"
Dallas,Texas "6.2-14.4"
[2]
AmericanRivers,NRDC,SmartGrowthAmerica."PavingOurWayto Water Shortages:
How Sprawl Aggravatesthe Effectsof Drought."2002. p 2.
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