A picture of what the world will look like if all the building had a green roof on top of  them.            

My experiment definitely has some characteristics that are relevant to real life. My experiment demonstrates which plant grows the fastest in a green roof. Although it does not show how a green roof works, it does however prove many good qualities of a green roof.

 

I also discovered the may benefits of green roofs that have a tremendous effect on us and the earth in which we live.

 

Benefit 1: Green roofs reduce stormwater runoff

During any heavy or continuous rain, runoff can overwhelm stormwater infrastructure and can very well damage rivers and fish habitat.

	Green roof vegetation retain rainwater and, together with plants, return                                   a portion of this water to the atmosphere through evaporation and transpiration.
	Stormwater that does leave the roof is delayed and reduced in volume.
	Stormwater that runs off a green roof is cleaner than runoff from a conventional roof.
	Retention and delay of runoff eases stress on stormwater infrastructure and sewers.
	The stormwater improvements have reduced the need to expand on renovate related                   infrastructure, thus reducing costs.

Rainfall and runoff comparison in the 2005 dry and wet seasons ( from the September 2006 CMHC Report).

 

Benefit 2: Green roofs are energy efficient

Green roofs reduce the heat flux through the roof, and less energy for cooling or heating can lead to significant cost savings. Shading the outer surface of the building envelope has been shown to be more effective than internal insulation.

In summer, the green roof protects the building from direct solar heat.

In winter, the green roof minimizes heat loss through added insulation on the roof.

Energy conservation translates into fewer greenhouse gas emissions.

 

Benefit 3: Green roofs improve air quality

Plant leaves trap dust particles from the air, and evaporation/transpiration cools ambient temperatures.

	Less ground level ozone + less heat = less smog.
	Reduced Urban Heat Island profile.
	Less need for health care services result in societal cost savings.

 

Temperatures in the urban core can be 3^o-5^o C warmer than rural and suburban areas. (Source: Lawrence Berkeley National Laboratory)

 

Benefit 4:Green roofs can serve as habitat

As undisturbed areas, rooftops can serve as refuge for creatures that struggle for survival. Ground-nesting birds, such as Killdeer, use green roofs for nesting and raising their young.

	Vegetated rooftop habitats can serve as stepping stones, to create corridors connecting                    other patches (roofscape or at grade) across an urban sea to natural habitats beyond                            the city.
	Natural habitats can serve as templates for green roofs designed for biodiversity.
	Low maintenance green roofs can be designed to serve as refuge for species such as                         ground-nesting birds.

A goose nest on a roof on Granville Island, Vancouver.

 

Benefit 5: Green roofs last longer

Green roofs cover the waterproofing membrane, protecting it from UV rays and extreme daily temperature fluctuations. This protection extends the lifespan of the waterproofing twice as long as conventional roofing, meaning that membranes under green roofs last twice as long as those on traditional roofs.

	Reduced material waste from re-roofing.
	Less frequent re-roofing, less costs over time.

Median daily temperature fluctuation experienced by the roof membrane of the three sections at the Green Roof Research Facility, by season September 2006 CMHC Report).

 

Benefit 6: Life cycle costs are competitive

The initial installation cost of a green roof is more than a traditional roof; however, the life cycle cost is competitive. You will eventually save so much more money than you pay. It will most definitely be worth it.

 

Benefit 7: Green roofs provide 'extra' space

Green roofs make the most of unused space within the increasing density of our cities. Rooftops can be developed into social and recreational spaces and used for urban agriculture.

	Amenity space for day care, meetings, and recreation.
	Improved artistic views for neighbors in adjacent buildings.
	Improved worker productivity and creativity.
	Potential to enhance urban food security through rooftop gardening and food production.

Benefit 8: Job created

 The multiplier effect takes place.

	Supply and manufacture of roofing membranes and root repellent layers, drainage layers,                    landscaping cloth, curbs, irrigation systems and other specialty products.
	Supply and manufacture of substrate, light-weight soils and amendments, plants.
	Design and engineering professionals, contractors and landscapers; and companies supplying               maintenance contracts.

 
 

Other Benefits

Green roofs offer so many benefits, it's hard to imagine listing them all. Here are a few more:

	By improving energy efficiency and addressing the "Urban Heat Island Effect", we can better                    prepared and adapted to climate change.
	Hospital patients with natural views require less medication and attention and may be discharged         sooner.
	Opportunities to recycle aggregate and compost.
	Potential for faster approval process for new projects (e.g. Chicago).
	Potential for reduced stormwater/ wastewater charges from municipality or utility.
	Potential to reduce the size of stormwater management ponds or cisterns, resulting in cost savings.
	Potential for grants related to energy efficiency and/ or green roofs.

 

 I believe that green roofs will be the wave of the future, the next big thing. They have so many helpful environmental contributions; help the community and the world.

 

 

 

 

NEXT STEPS

 

 After completing this science fair experiment, I have a few questions like, “what other plants are suitable for a green roof” and “what will the next step be for scientists and architects with the green roof idea.” I also would like to know how green roofs control of storm water runoff. To find out what other plants are suitable for a green roof, I could repeat the experiment I just completed only using different plants. My second questions will be hard for me to do an experiment about because I don’t know how scientists and architects will approach the green roof idea. I don’t know what they are going to do next, however they could already be improving the current green roofs and advancing them. Also, to find out how green roofs decrease storm water runoff, I could make four control roofs with black EPDM membrane surfaces only and four commercial Green Roof Blocks and place them outside. Then after each rain event, I will record the rainfall date and determined from the two rain gauges located on a table at the field site. This would probably prove whether green roofs reduce storm water runoff.