Benefits I.Stormwater Mitigation II.Urban Heat Island Effect Mitigation III.Cooling/Heating Load Assistance IV.Extended Roof Lifespan V.Air/Water Purification VI.Sound Deadening VII.Creation of Wildlife Habitat VIII.Psychological Benefits and Aesthetic Improvements IX.Value of Building Increases X.Cost Effective!! – Ecoroofs Cost More, Right?? Marketing Green Roofs - Exercise Hawthorne Condominiums

Photo Courtesy Tom Liptan In Portland, as in most areas, stormwater is now recognized as the number one cause of degraded urban stream health. This is an especially serious issue for our Rainy City because our waterways once supported wild populations of salmon. I. Benefits Stormwater Mitigation: Degraded Runoff The city is developing a “stormwater discount” that may give a significant savings off the water bill. Stormwater fees are projected to increase significantly in the near future and may grow to 35% of our water bill. We may save up to 100% of this portion of the bill.

Plants absorb rainwater for photosynthetic processes Plants reintroduce water into the air through evapotranspiration The soil acts like a sponge, absorbing water, much of which is released to the air through evaporation. These processes typically absorb 30% to 50% of rainwater that falls on ecoroofs in Portland The effect on the storm sewer systems is a lower peak and a flattened curve for stormwater flow This effects temperature, peak flow, and quality of the remaining runoff There is Five to Seven times more residential rooftop than Commercial Rooftop area –And this Provides a great opportunity to reclaim our watersheds! The Rainwater Sponge A 1,500 sq. ft. roof will shed 34,000 gallons of rainwater a year.

Public Benefit to the Urban Climate I. Benefits Urban Heat Island Effect: II. Urban Heat Island Effect

III. Cooling/Heating Load Assistance: Surface temp reduction of 14 – 22 deg.F during summer. ( 4” of soil) Significant wind chill reduction, reducing heat demand by 5% to 25% Greenroofs function as either an insulator or heat sink, depending on moisture level. Either way, they help mitigate temperature extremes. The Biggest Benefit Realized to the Property Owner is Realized in Summer Cooling Costs –HVAC air conditioning units on greenroofs take in cooled air instead of superheated air. Energy Savings is Significant during the Summer months. –Evaporation of moisture in Soil and Plants Cools the Roof Significantly, Helping to Cool the Entire Story Immediately Below It. –Any Energy Savings during peak hours (like with air conditioning use) translates into a need for less energy generating infrastructure. The real savings here is far greater than the savings you see on your electricity bill. Graphic courtesy of Zincoflor Cold Hot Photo Courtesy Tom Liptan

Hawthorne Hostel Ecoroof Installed August 2002 IV. Less Likely to Leak than Asphalt or Shingles, And Lasts 2-3 Times As Long! It All Starts with a Higher Quality Membrane System, Designed to Last at Least 20 Years on a regular roof system. It’s Topped with Soil and Plants, Both of which Protect it from its two Enemies, Cumulative Sunlight Exposure, and Temperature Extremes Sunlight’s UV Rays Eventually Lead to Failure of the Elastomers Temperature Fluctuations or Extremes Lead to Overflexing the roofing materials beyond their capacity. But Ecoroofs function as either heat sinks or insulation, thereby holding a more constant temperature at the membrane level. At the same time, the plants absorb the sun’s rays and also help shade the soil, which, of course, shades and protects the membrane!

V. Sound Reduction: Absorbs both ambient and penetrating sound waves Sound insulation improved by up to 8 dB Reflected sound reduced by up to 3 dB Vegetation absorbs high frequencies Soil absorbs lower frequencies Graphic Courtesy Zincoflor Photo courtesy of American Hydrotech Building in the flight path of an Airport

VI. Air/Water Purification: Vegetation Reduces Dust by Trapping Particles Nitrates and other harmful materials are filtered out of rainwater and air and bound within the soil. Beneficial Effect on Water Turbidity, Chemistry, and Temperature of Runoff Absorbs Carbon Dioxide, Produces Oxygen Residential Greenroof in Germany

VII. Wildlife Benefits: Wildlife Habitat and Greenspace Created up to 100% of Building Footprint Inviting Nature back into the built environment Increasing our Urban Biodiversity Beekeeper’s Roof Provides Nectar for His Native Honeybees

VIII. Livability/Aesthetic Benefits Eliminates Glare Creates an “Amenity” Positive Social Effect, Showcasing Stewardship of the Earth. Positive Psychological Effect Possible to Grow Food on Ecoroofs. Harvest Fresh Herbs for Cooking

IX. Value of Property Increases Once Banks recognize greenroofs as “amenities” they will be willing to loan out more money for projects involving greenroofs. Property Instantly Recognized as “Green” if roof is visible Ecoroofs can Create a Beautiful View, thereby Increasing Property Values, or Rental Rates

You are Learning about Lower-Cost, Locally-Available Materials and Designs Successfully Installed in Our Area. An Example of Low Cost Materials, Used in an Ecoroof Costing $7.50/ ft2. (materials and retrofit) Graphic Courtesy of Steve Cowden, The Oregonian X. Cost Effective, with the right knowledge!

Former Ecoroof Workshop Location Or… Same Cost as a Regular Roof! Because greenroofs Last 2-3 times as long, over the life of the roof, they save the cost of at least one conventional reroofing. If it outlasts the conventional roof by three times, the greenroof can cost the same as a regular roof. This is called “Life Cycle Cost Analysis” Most Homeowners and Developers use Up Front Cost Analysis, However.

List All the Private, and Public Benefits for the Following Project: New Garage – ( 400 ft2 roof, 20 lbs/ft2) Mandated Stormwater Mitigation Required for Further Site Development Homeowners are an Avid Cook, and a Landscape Architect Roof is Visible from Second Floor of House and 2 Neighbors’ Homes as Well Homeowners Plan to Keep the Property for at Least 20 Years (Project is Using Cost Effective and Best Practices, like We’re Learning in Class) Public BenefitsPrivate Benefits