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ENERGY INDEPENDENCE Green Roofs

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					ENERGY INDEPENDENCE:
     Green Roofs –
   Implementation and
        Feasibility
       Chris Gardino
           History of Green Roofs
           in ancient
► Originated
  Mesopotamia

► Vikingsod roofs in
  Scandinavia



► Sod   roofs in Africa
        Green Roofs: Generally
► Growing   medium is
  part of the roof

► Layersof a
  contemporary green
  roof




                        Cross Section of a Green Roof
                Decking
► Canbe constructed from wood, metal
 concrete, plastic, gypsum, or composite



► Concretedecking will provide the most
 sound structural support
           Waterproofing Layer
► Very important to make sure
 that there is an effective seal

► There   are four different methods
 of   waterproofing
 -     Built up roof
 -     Modified Bitumen roof
 -     Single Ply membrane
 -     Liquid applied membrane
               Insulation
► Properinsulation will promote the energy
 saving advantages of green roofs



           can either be placed above or
► Insulation
 below the waterproof membrane
   Protection and Storage Layer
► Must be placed above the
  waterproof membrane




► Usuallyconstructed with PVC
  or HDPE sheets
               Drainage Layer
► Drainage layer is critical to
 the health of the plants
 and the roof system

► Drainage  systems are very
 site specific
                Filter Layer
► Root   permeable

► Basicallyseparates the medium from the
  drainage layer to avoid clogging

► Couldbe a filter cloth or some other semi-
  permeable fabric
             Growing Medium
► Green  roof plants need to grow in a medium
 that is porous

► Idealmixture is about 75 to 90 percent
 inorganic material with the remainder
 consisting of compost

► Depth   of medium will vary with the type of
 roof
           Extensive Green Roofs
► Typically less than 6
  inches of soil

► Usually   not open to
  public

► Low   plant diversity

► Minimal cost to
  maintain
           Intensive Green Roofs
► Deeper and more
 organic soils

► Often   open to the
 public

► More    plant diversity

► Higher   maintenance
 costs
    Semi-Intensive Green Roofs
► Between  intensive and
  extensive green roofs
  regarding maintenance
  and support capacity

► Semi-public   purpose
                Plant Selection
► Will   be extremely site specific

► Generally Green Roof plants will be tougher
  and less nutrient reliant than plants found in
  ground gardens

► Elevationwill carry certain dangers not
  found on the ground
                   Annuals
► Annuals are plants that grow, flower and seed in
  one season
► Should not be dominant in green roofs: used more
  as an accent
       Herbaceous Perennials
► Herbaceous  perennials are some of the
  most desirable green roof plants
► Advantages: aesthetically pleasing, lots of
  variety
► Disadvantages: Most have limited drought
  tolerance, will require deeper substrate,
  biomass accumulates as they grow, very
  few are evergreen
Some Well Suited Herbaceous
        Perennials



 Dianthus            Phlox




 Petrorhagia       Campanula
          Hardy Succulents
► Hardy Succulents are the best suited plants
 for green roofs

► Advantages:can survive drought/ wind/
 temperature extremes, store water for
 extended periods, shallow root systems

► Onlyviable option for certain shallow soil
 extensive roofs
Sedums
   ►   Nearly 600 species
       available

   ►   Found in well drained
       areas

   ►   Long life span and self-
       propagating

   ►   Change color with the
       seasons
 Other Hearty Succulents



                  Talinum




Delosperma       Sempervivum
                     Grasses
► Grasses   can add texture and habitat

► Require  deeper medium for root systems and
  larger biomass
                    Herbs
► Herbs   can be very tolerant once established

► Mayrequire deeper substrate for less
 ground cover

► Added   culinary and olfactory perks
            Groundcovers
► Groundcover  plants provide dense soil
 cover, retard weed growth, and prevent soil
 erosion

► Mostof the plants on a green roof should
 be low density ground covers

      for rapid and reliable growth at a
► Allow
 reasonable price
                Accents
► Accentplants may not live over five years
 and will require more care and maintenance



► Many  of the aforementioned annuals make
 for viable options as accent plants
                 Natives
► Nativeplants often function in an ecological
 system which makes their inclusion in green
 roofs somewhat difficult

► Advantages:already adapted to local
 weather conditions, resistance to local pests
 etc.
                 Cost!!!!
► Thecost for implementing a green roof in
 the United States is about $15-$20/sq ft

► Theprice of a conventional roof runs about
 $8-$10/sq ft

► Theprice of a green roof is offset by long
 term cost saving
          Energy Independence
► Heating/cooling   energy

► Green roofs can reduce heat consumption during
  the winter months

► Green roofs will keep air conditioner use down in
  the summer months

     also keep surrounding areas cooler in the
► Will
  summer months
         Urban Heat Island
► Mostsuburbs and city roofs are made in
 shades of gray and black which tend to soak
 up heat and UV



► Thiscontributes to the phenomenon known
 as the ‘urban heat island effect’
Urban Heat Island
Carbon Dioxide and Other Particulate
              Matter

► Greenroofs will naturally absorb excess CO2
 through photosynthesis



► Greenroof plants can also remove harmful
 or unwanted particulate matter (dust)
                 Water Run-Off
► Excess   runoff is costly

► About 75% of
 rainwater in urban
 areas becomes surface
 runoff

► Green roofs can
 mitigate surface water
 runoff
                              ABOUT 1.5% OF THE UNITED STATES IS COVERED
                              IN IMPERVIOUS SURFACES: AN AREA ABOUT THE
                              SIZE OF OHIO
               Other Benefits
► Habitat
► Aesthetics
► Worker Productivity
► Sound Insulation
Green Roofs and the Law: Incentives
          and Mandates
► Mostcontemporary legislation relating to
 green roofs is based upon incentives

► Germanyoffers individuals 15 euros per
 square meter of green roof

            requires that 25 percent of new
► Switzerland
 commercial development be greened
 Domestic Green Roof Incentives
► Chicago is at the
 forefront

► Tax   incentives

► Water   run-off credits

► OpenSpace
 Requirements
                            South Loop Target Store
                CONCLUSION
► Greenroofs provide an opportunity to use
 otherwise wasted space in a way that
 promotes energy independence

            should follow the lead of
► Legislators
 European countries in promoting the
 development of green roofs to offset the
 loss of open spaces through incentives and
 mandates

				
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