Green RoofsGreen RoofsLID & Sustainable DesignLID & Sustainable Design

Jessica AbreraJessica Abrera

Intensive vs. ExtensiveIntensive vs. ExtensiveIntensiveIntensive

More time, money, More time, money, and energyand energyLiving and Living and recreational spacerecreational spaceMore aesthetically More aesthetically pleasingpleasing

ExtensiveExtensiveSimpleSimpleBasicBasic““GetGet’’s the job done.s the job done.””

Green Roof LayersGreen Roof Layers

Plant SelectionPlant SelectionDependent Upon:Dependent Upon:

Substrate DepthSubstrate DepthExtreme Extreme TemperaturesTemperaturesHigh Light IntensitiesHigh Light IntensitiesHigh Wind SpeedsHigh Wind SpeedsBuilding Building InfrastructureInfrastructureMaintenanceMaintenance

TypesTypesLow, matLow, mat--formingformingCompact growthCompact growthEvergreen foliageEvergreen foliageTough, twiggy growthTough, twiggy growthDrought tolerantDrought tolerantWaterWater--storingstoring

Building StructureBuilding Structure

Tall buildings have Tall buildings have greater supportgreater supportSmaller oneSmaller one--story story buildings need more buildings need more column support if it column support if it covers a greater areacovers a greater areaErosion control for Erosion control for buildings with a slopebuildings with a slope

LIDLID

Decrease the load of storm Decrease the load of storm water runoff to the wastewater water runoff to the wastewater treatment plantstreatment plantssize of cisterns and stormsize of cisterns and storm--water water management ponds are also management ponds are also reduced reduced The precipitation is absorbed by The precipitation is absorbed by the substrate for the vegetation the substrate for the vegetation and then is released through and then is released through evaportranspiration evaportranspiration Green roofs hold 70Green roofs hold 70--90% of the 90% of the precipitation during the summer, precipitation during the summer, and 25and 25--40% of the precipitation 40% of the precipitation during the winter is retained during the winter is retained Substrate depth is the main Substrate depth is the main determinant of runoff retention determinant of runoff retention

FiltrationFiltrationAirAir

1m^2 plot of grass can 1m^2 plot of grass can remove up to 0.2 remove up to 0.2 kilograms of airborne kilograms of airborne particulates from the air particulates from the air carbon dioxide is carbon dioxide is converted into oxygen converted into oxygen during photosynthesis during photosynthesis 1.5 square meter plot of 1.5 square meter plot of uncut grass generates a uncut grass generates a sufficient amount of sufficient amount of oxygen per year to one oxygen per year to one human with their yearly human with their yearly oxygen intake oxygen intake requirement requirement

WaterWater““naturalnatural”” filters for any filters for any pollutants carried in by pollutants carried in by the rain the rain Bioremediation and Bioremediation and phytoremediation phytoremediation performed by the performed by the bacteria and fungi in the bacteria and fungi in the substrate substrate

Roof Longevity Roof Longevity

roofs can be sustained roofs can be sustained for long periods of time for long periods of time without needing major without needing major repairsrepairsrooftops with green rooftops with green coverage can last more coverage can last more than 20 years than 20 years green roofs protect the green roofs protect the rooftops from damaging rooftops from damaging sunrays sunrays

Heat InsulatorHeat Insulator

conventional roof can reach up to 180conventional roof can reach up to 180ºº F, F, while a green roof will only warm up to while a green roof will only warm up to 8080ºº F F there is a reduction in heat flux because there is a reduction in heat flux because the green roof promotes the green roof promotes evapotranspiration, shades the roof, and evapotranspiration, shades the roof, and increases the insulation and thermal increases the insulation and thermal massmass

Urban Heat Island EffectUrban Heat Island Effect

The Urban Heat Island Effect is the The Urban Heat Island Effect is the temperature difference between an urban area temperature difference between an urban area and a rural, less populated area.and a rural, less populated area.Solar radiation is absorbed by roads and Solar radiation is absorbed by roads and buildings then rebuildings then re--radiated back as heat. radiated back as heat. One meterOne meter--squared area of vegetation can squared area of vegetation can evaporate 0.5 liters of water on a hot summer evaporate 0.5 liters of water on a hot summer day and 700 liters annually.day and 700 liters annually.Dust and particulate matter in the air Dust and particulate matter in the air contributing to smog will decrease contributing to smog will decrease

Sound InsulationSound Insulation

Sound waves generated from machines, traffic, and Sound waves generated from machines, traffic, and airplanes can be absorbed, reflected, or deflected with airplanes can be absorbed, reflected, or deflected with green roofs.green roofs.The vegetation of a green roof can block higher frequencies The vegetation of a green roof can block higher frequencies than the substrate and a substrate layer that is 12 cm thick than the substrate and a substrate layer that is 12 cm thick can reduce sound by 40 decibels and a 20 cm thick can reduce sound by 40 decibels and a 20 cm thick substrate layer can decrease sound by 46substrate layer can decrease sound by 46--50 decibels.50 decibels.

EcosystemEcosystem

mimic endangered mimic endangered ecosystems/habitats ecosystems/habitats rare and uncommon rare and uncommon species of insectsspecies of insectsGreen roofs provide Green roofs provide a safe haven for a safe haven for different species of different species of birds, insects, and birds, insects, and plants and they plants and they promote biodiversity. promote biodiversity.

Therapeutic BenefitsTherapeutic Benefitsproviding providing ““visual reliefvisual relief””improve human health with relaxation and restorationimprove human health with relaxation and restoration

Roof GardenRoof Garden

Growing herbs, fruits, Growing herbs, fruits, flowers, and vegetables flowers, and vegetables on a green roof helps on a green roof helps make produce more make produce more accessible. accessible. Green roofs provide Green roofs provide fresher produce, limit the fresher produce, limit the food miles, or distance food miles, or distance produce is transported, produce is transported, and give more control of and give more control of soil, fertilizer, and soil, fertilizer, and pesticides. pesticides.

Economic BenefitsEconomic Benefits

energy savings from energy savings from insulation insulation reduction in cost for not reduction in cost for not replacing or maintaining replacing or maintaining a conventional roofa conventional roofsavings derived from not savings derived from not treating large amounts of treating large amounts of storm water runoff storm water runoff

reduction or elimination reduction or elimination of roof drains and of roof drains and standard insulationstandard insulationnew job opportunitiesnew job opportunitiesreduction in cost of reduction in cost of meeting the greenhouse meeting the greenhouse gas requirementsgas requirementsdecreased construction decreased construction for storm water related for storm water related infrastructure infrastructure recycling of aggregate recycling of aggregate and compost and compost

CostsCosts

depth and type of the depth and type of the substratesubstratetype of vegetationtype of vegetationthe size of the size of installationinstallationwhether irrigation is whether irrigation is used or notused or notif it is extensive or if it is extensive or intensive intensive

The price range of green roofs is from $8 to $28 per square foot, with $10 to $12 around the average.

MaintenanceMaintenance

Watering, weeding, Watering, weeding, pruning, and repruning, and re--application of organic application of organic fertilizer, and defertilizer, and de--clogging drains and clogging drains and gutters are all a part of gutters are all a part of maintaining a green roof.maintaining a green roof.The first two years of The first two years of maintenance is when the maintenance is when the price is the highest.price is the highest.A green roof must be A green roof must be maintained four to five maintained four to five times a year.times a year.

The EndThe End