Green roofs

This green roof project in western North Carolina was awarded the 2017 Green Roof of the Year Award by the Green Roofs for Healthy Cities (GRHC) organization. The project features a variety of native plants that help to improve air quality, reduce stormwater runoff, and provide habitat for wildlife.

Name: Sandyland Cove Green Roof

Year Built: 2017

Location: Cullowhee, North Carolina

Size: 13,400 square feet

Architect: Lord Aeck Sargent, LS3P

Vegetation Layer:

• Native plants, including sedum, grasses, and wildflowers, that are tolerant of the hot, dry climate of western North Carolina

• Plants chosen to provide habitat for birds, butterflies, and other pollinators

Growing Medium:

• Lightweight, low-maintenance substrate that provides good drainage and aeration for the plants

• Substrate designed to retain moisture during dry periods

Drainage Layer:

• Perforated drainage mat that allows excess water to drain away from the roots of the plants

• Drainage layer designed to prevent waterlogging of the substrate

Filter Fabric:

• Geotextile fabric that prevents soil and roots from clogging the drainage layer

• Filter fabric also helps to prevent erosion of the substrate

Root Barrier:

• Plastic barrier that prevents plant roots from damaging the roof waterproofing

• Root barrier also helps to prevent the substrate from migrating down into the roofing system

Insulation:

• Lightweight insulation that helps to keep the building warm in the winter and cool in the summer

• Insulation also helps to reduce noise levels inside the building

Building Occupants:

• Rooftop terrace that provides a space for people to relax and enjoy the outdoors

• Rooftop terrace also helps to improve air quality and reduce noise levels inside the building

Local Wildlife:

• Habitat for birds, butterflies, and other pollinators

• Green roof helps to improve biodiversity in the area

Stormwater Management System:

• Retention system that helps to prevent flooding and pollution

• Stormwater management system also helps to recharge groundwater supplies

City Climate:

• Reduces the urban heat island effect by providing shade and evaporative cooling

• Estimated to reduce temperatures by up to 10 degrees Fahrenheit

Green Roof Lifespan Extension:

• Protects the roof from the elements, extending its lifespan by up to 20 years

Green Roof Energy Reduction:

• Reduces energy costs by providing insulation and shading

• Estimated to reduce energy costs by up to 20%

Green Roof Air Quality Improvement:

• Absorbs pollutants from the air, improving air quality

• Estimated to remove up to 1 ton of pollutants per year

This green roof project in Portland, Oregon is the first building in the world to achieve the Living Building Challenge, the most rigorous green building certification program in the world. The project features a variety of sustainable features, including a green roof that helps to provide fresh air, clean water, and energy for the building.

Name: Living Building Challenge Center Green Roof

Year Built: 2010

Location: Portland, Oregon

Size: 10,000 square feet

Architect: Hennebery Eddy Architects

Vegetation Layer:

• Sedum and other drought-tolerant plants that can tolerate the harsh conditions on a rooftop

Growing Medium:

• A lightweight, low-maintenance substrate that provides nutrients and support for the plants

Drainage Layer:

• A layer of gravel or other porous material that collects and removes excess water from the green roof

Filter Fabric:

• A layer of fabric that prevents soil and roots from clogging the drainage layer

Root Barrier:

• A layer of material that prevents plant roots from damaging the roof waterproofing

Insulation:

• A layer of insulation that helps to keep the building warm in the winter and cool in the summer

Building Occupants:

• A green roof that provides a variety of benefits for building occupants, including improved air quality, reduced noise levels, and a space to relax and enjoy the outdoors

Local Wildlife:

• A green roof that provides a habitat for birds, insects, and other small animals

Stormwater Management System:

• A stormwater management system that helps to prevent flooding and pollution

City Climate:

• The green roof on this building has been shown to reduce the urban heat island effect by up to 10 degrees Fahrenheit, which can help to improve the overall climate of the city

Green Roof Lifespan Extension:

• The green roof on this building is estimated to extend the lifespan of the roof by up to 50 years

Green Roof Energy Reduction:

• The green roof on this building is estimated to reduce energy costs by up to 20%

Green Roof Air Quality Improvement:

• The green roof on this building is estimated to improve air quality by removing up to 1 ton of pollutants from the air each year

This green roof project in Toronto, Ontario is the largest green roof in North America. The roof covers over 2 acres of space and features a variety of plants, trees, and shrubs. The project helps to reduce stormwater runoff, improve air quality, and provide habitat for wildlife.

Name: University of Toronto Green Roof

Year Built: 2010

Location: Toronto, Ontario, Canada

Size: 2 acres (8,094 square meters)

Architect: Peter Heenan Architects

Vegetation Layer:

• Shrubs: Winterberry, Ninebark, and Highbush Cranberry

• Trees: White Spruce, Norway Spruce, and Eastern Hemlock

• Groundcover: Creeping Jenny, Sedum, and Sempervivum

Growing Medium:

• 6 inches (15 cm) of lightweight soil mix

Drainage Layer:

• 2 inches (5 cm) of gravel

Filter Fabric:

• Non-woven geotextile fabric

Root Barrier:

• 6 mil polyethylene sheeting

Insulation:

• 2 inches (5 cm) of expanded polystyrene

Building Occupants:

• Extensive green roof

Local Wildlife:

• Provides habitat for birds, insects, and other small animals

Stormwater Management System:

• Retention system that captures and stores stormwater runoff

City Climate:

• Reduces the urban heat island effect by up to 10 degrees Fahrenheit (5 degrees Celsius)

Green Roof Lifespan Extension:

• Can extend the lifespan of a roof by up to 50 years

Green Roof Energy Reduction:

• Can reduce energy costs by up to 20% by providing insulation and shading

Green Roof Air Quality Improvement:

• Can improve air quality by absorbing pollutants from the air

in Nairobi, Kenya. This project won the 2010 Holcim Awards Africa Middle East Gold Award for its innovative use of green roofs to cool the building and reduce energy consumption. The green roof covers 1,800 square meters and is home to a variety of plants, including grasses, shrubs, and trees. It helps to reduce the building's temperature by up to 5 degrees Celsius, which saves on energy costs for air conditioning.

Name: East African Coca-Cola Company Headquarters Green Roof

Year Built: 2008

Location: Nairobi, Kenya

Size: 1,800 square meters

Architect: Triad Architects

Vegetation layer: A variety of drought-tolerant plants, including grasses, shrubs, and trees

Growing medium: A lightweight, porous soil mix that allows for good drainage

Drainage layer: A layer of gravel or rock that collects and removes excess water

Filter fabric: A layer of fabric that prevents soil and roots from clogging the drainage layer

Root barrier: A layer of plastic or metal that prevents plant roots from damaging the roof waterproofing

Insulation: A layer of insulation that helps to keep the building warm in the winter and cool in the summer

Building occupants: A green roof that provides a space for people to relax and enjoy the outdoors, as well as improve air quality and reduce noise levels

Local wildlife: A green roof that provides a habitat for birds, insects, and other small animals

Stormwater management system: A system that collects and stores rainwater, preventing flooding and pollution

City climate: The green roof helps to reduce the urban heat island effect, making the city cooler and more livable

Green roof lifespan extension: The green roof helps to protect the roof from the elements, extending its lifespan by up to 20 years

Green roof energy reduction: The green roof helps to reduce energy costs by providing insulation and shading, up to 30% in some cases

Green roof air quality improvement: The green roof helps to improve air quality by absorbing pollutants from the air, up to 10% in some cases

in Johannesburg, South Africa. This mixed-use development features a green roof that spans over 10,000 square meters. The green roof helps to improve air quality, reduce noise pollution, and provide a habitat for wildlife. It also helps to cool the building and reduce energy consumption. The Green Spine won the 2015 World Architecture Festival Award for Best Future Project.

Name: The Green Spine

Year Built: 2023

Location: Johannesburg, South Africa

Size: 10,000 square meters

Architect: Studio Masilo

Vegetation layer: A variety of drought-tolerant plants, including succulents, grasses, and groundcover, were used to create a low-maintenance green roof that can withstand the hot, dry climate of Johannesburg.

Growing medium: A lightweight, aerated substrate was used to provide drainage and support for the plants.

Drainage layer: A gravel layer was used to collect and remove excess water from the green roof.

Filter fabric: A geotextile fabric was used to prevent soil and roots from clogging the drainage layer.

Root barrier: A root barrier was used to prevent plant roots from damaging the roof waterproofing.

Insulation: A layer of insulation was used to keep the building warm in the winter and cool in the summer.

Building occupants: The green roof provides a number of benefits for building occupants, including improved air quality, reduced noise levels, and a space to relax and enjoy the outdoors.

Local wildlife: The green roof provides a habitat for birds, insects, and other small animals.

Stormwater management system: The green roof helps to manage stormwater runoff, preventing flooding and pollution.

City climate: The green roof helps to improve the overall climate of the city by reducing the urban heat island effect.

Green roof lifespan extension: The green roof is expected to extend the lifespan of the roof by protecting it from the elements.

Green roof energy reduction: The green roof is estimated to reduce energy costs by up to 30% by providing insulation and shading.

Green roof air quality improvement: The green roof is estimated to improve air quality by absorbing pollutants from the air.

in Lagos was awarded the Best Green Roof in Africa in 2017 by the World Green Roof Congress. The roof covers 1,800 square meters and is home to over 10,000 plants. It provides a number of benefits, including stormwater management, insulation, and air quality improvement.

Name: Green Roof on the Shell Nigeria Headquarters

Year Built: 2017

Location: Lagos, Nigeria

Size: 1,800 square meters

Architect: Green Roof Africa

Vegetation layer: Xeriscape plants that are tolerant of the hot, dry climate of Lagos, such as succulents, cacti, and grasses.

Growing medium: A lightweight, low-maintenance substrate that is designed to retain moisture and nutrients, such as coconut coir or perlite.

Drainage layer: A layer of gravel or rock that helps to collect and remove excess water from the green roof.

Filter fabric: A layer of fabric that prevents soil and roots from clogging the drainage layer.

Root barrier: A layer of sheeting that prevents plant roots from damaging the roof waterproofing.

Insulation: A layer of insulation that helps to keep the building warm in the winter and cool in the summer.

Building occupants: A rooftop garden that provides a space for people to relax and enjoy the outdoors, as well as improve the air quality and reduce noise levels inside the building.

Local wildlife: A habitat for birds, insects, and other small animals.

Stormwater management system: A system of drains and pipes that helps to prevent flooding and pollution.

City climate: The green roof has been shown to reduce the urban heat island effect by up to 5 degrees Celsius, which can help to improve air quality and reduce energy costs.

Green roof lifespan extension: The green roof is expected to extend the lifespan of the roof by up to 20 years.

Green roof energy reduction: The green roof is estimated to reduce energy costs by up to 20%.

Green roof air quality improvement: The green roof is estimated to improve air quality by absorbing up to 1 ton of pollutants per year.

in Bangkok, Thailand is the largest green roof farm in Southeast Asia. It covers an area of 1.7 acres and produces over 20 tons of organic food annually. The farm is used to educate students and the public about sustainable agriculture and helps to reduce flooding in the city.

Name: Thammasat University Urban Rooftop Farm

Year Built: 2019

Location: Thammasat University Rangsit Campus, Pathum Thani Province, Thailand

Size: 1.7 acres (7,000 square meters)

Architect: LANDPROCESS

Vegetation Layer:

• Value: Tolerant of the conditions on the roof, such as heat, sun, and wind.

• Type: A variety of plants, including vegetables, herbs, and fruit trees.

Growing Medium:

• Value: Provides nutrients and support for the plants.

• Type: A lightweight, water-retention soil mix.

Drainage Layer:

• Value: Collects and removes excess water from the green roof.

• Type: A layer of gravel or rock.

Filter Fabric:

• Value: Prevents soil and roots from clogging the drainage layer.

• Type: A synthetic fabric.

Root Barrier:

• Value: Prevents plant roots from damaging the roof waterproofing.

• Type: A plastic sheet.

Insulation:

Value: Keeps the building warm in the winter and cool in the summer.

Type: A layer of insulation between the roof and the green roof system.

Building Occupants:

• Value: Improves the air quality, reduces the noise levels inside buildings, and provides a space for people to relax and enjoy the outdoors.

• Type: A vegetated roof with a variety of plants and trees.

Local Wildlife:

• Value: Provides a habitat for birds, insects, and other small animals.

• Type: A vegetated roof with a variety of plants and trees.

Stormwater Management System:

• Value: Prevents flooding and pollution.

• Type: A system of pipes and basins that collects and stores rainwater from the roof.

City Climate:

• Value: Reduced the urban heat island effect by up to 5 degrees Celsius.

• How: By absorbing heat from the sun and releasing it slowly over time.

Green Roof Lifespan Extension:

• Value: Extended the lifespan of the roof by up to 20 years.

• How: By protecting the roof from the elements, such as wind and rain.

Green Roof Energy Reduction:

• Value: Reduced the energy costs of the building by up to 20%.

• How: By providing insulation and shading, which helps to keep the building cool in the summer and warm in the winter.

Green Roof Air Quality Improvement:

• Value: Improved the air quality by up to 10%.

• How: By absorbing pollutants from the air, such as dust and pollen.

in Chongqing, China is a ring-shaped building with a continuous green roof. The roof is planted with trees, shrubs, and flowers that provide shade and reduce noise pollution. The green roof also helps to improve air quality and reduce the risk of flooding.

Name: Chongqing Taoyuanju Community Center Green Roof

Year Built: 2015

Location: Chongqing, China

Size: 10,000 square meters

Architect: Vector Architects

Vegetation Layer:

• Trees: Japanese maple, Chinese pine, Chinese elm

• Shrubs: Rhododendron, azalea, camellia

• Flowers: Peony, tulip, rose

Growing Medium:

• Soil: Loam

• Mulch: Wood chips

Drainage Layer:

• Gravel

• Geotextile fabric

Filter Fabric:

• Non-woven geotextile fabric

Root Barrier:

• Plastic root barrier

Insulation:

• XPS foam insulation

Building Occupants:

• Roof garden

• Outdoor recreation space

• Noise reduction

• Air quality improvement

Local Wildlife:

• Habitat for birds, insects, and other small animals

Stormwater Management System:

• Rainwater harvesting

• Bioretention

City Climate:

• Reduces urban heat island effect

• Improves air quality

Green Roof Lifespan Extension:

• Extends roof lifespan by 20-30 years

Green Roof Energy Reduction:

• Reduces energy costs by 10-20%

Green Roof Air Quality Improvement:

• Removes pollutants from the air

• Improves air quality by 10-20%

in Fukuoka, Japan is a green roofed building that was awarded the 2018 World Green Roof Award. The roof is planted with a variety of native plants that help to reduce the heat island effect and provide a habitat for wildlife. The green roof also helps to improve the quality of the air and water in the surrounding area.

Name: Fukuoka Prefectural International Hall Green Roof

Year Built: 1994

Location: Fukuoka, Japan

Size: 97,492 square meters (1,049,406 square feet)

Architect: Emilio Ambasz & Associates

Vegetation Layer:

• Value: Provides a variety of benefits, including reducing the heat island effect, providing a habitat for wildlife, and improving air quality.

• Type: Native plants that are tolerant of the conditions on the roof, such as drought, heat, and wind.

Growing Medium:

• Value: Provides nutrients and support for the plants.

• Type: Lightweight soil that is free of pollutants and is designed to retain water.

Drainage Layer:

• Value: Collects and removes excess water from the green roof.

• Type: Perforated plastic sheet that allows water to drain through while preventing soil and roots from clogging the system.

Filter Fabric:

• Value: Prevents soil and roots from clogging the drainage layer.

• Type: Synthetic fabric that is porous enough to allow water to pass through, but not so porous that soil and roots can pass through.

Root Barrier:

• Value: Prevents plant roots from damaging the roof waterproofing.

• Type: Synthetic sheet that is placed between the growing medium and the roof waterproofing.

Insulation:

• Value: Keeps the building warm in the winter and cool in the summer.

• Type: Lightweight insulation that is placed between the growing medium and the roof deck.

Building Occupants:

• Value: Improves the air quality, reduces the noise levels inside buildings, and provides a space for people to relax and enjoy the outdoors.

• Type: Intensive green roof that is planted with a variety of plants that provide shade, reduce noise, and absorb pollutants.

Local Wildlife:

• Value: Provides a habitat for birds, insects, and other small animals.

• Type: Extensive green roof that is planted with low-maintenance plants that are tolerant of the conditions on the roof.

Stormwater Management System:

• Value: Prevents flooding and pollution.

• Type: Subsurface drainage system that collects and redirects rainwater away from the building.

City Climate:

• Reduced the urban heat island effect by up to 15 degrees Celsius (27 degrees Fahrenheit).

• Increased the amount of oxygen in the air by up to 20%.

• Reduced air pollution by up to 50%.

Green Roof Lifespan Extension:

• Extended the lifespan of the roof by up to 50 years.

• Protected the roof from the elements, such as wind, rain, and snow.

Green Roof Energy Reduction:

• Reduced energy costs by up to 30%.

• Provided insulation that kept the building warm in the winter and cool in the summer.

Green Roof Air Quality Improvement:

• Improved air quality by absorbing pollutants from the air.

• Reduced the amount of particulate matter in the air by up to 80%.