"Discover How The Chicago Green Roof Initiative 
Transformed Green Roofing Into An Energy Saving
Environmentally Friendly, Cost Cutting Masterpiece!"

How This Works (For You)

Cool roofs for commercial and industrial buildings fall into one of three categories: roofs made from inherently cool roofing materials, roofs made of materials that have been coated, or green planted roofs.

One of the ways to make an existing or new roof reflective is by applying a specifically designed white roof coatings (not simply white paint) on the roof's surface.

The coating must be Energy Star rated. Reflectivity and emissivity ratings for all reflective roof products can be found in the CRRC (Cool Roofs Rating Council) website.

Energy Efficient, Green Roofs

A traditional vegetative green roof consists of an insulation layer, a waterproof membrane, and a drainage layer usually made of lightweight gravel, clay, or plastic.

A geotextile or filter mat that allows water to soak through but prevents erosion of fine soil particles; a growing medium; plants; and, sometimes, a wind blanket.

Green roofs are classified as either intensive or extensive; some green roof designs incorporate both intensive and extensive elements.

Intensive green roofs require at least one foot of soil and appear as a traditional garden with trees, shrubs and other attractive landscapes. They are multi-layer constructions with elaborate irrigation and drainage systems.

These roofs are often designed for recreational purposes and accommodate foot traffic. Intensive green roofs add considerable load to a structure and require intensive maintenance, so they are more common with large businesses or government buildings rather than free-standing homes.

Your New Green Roof Will Beat The Heat... Literally!

Extensive roofs usually require less maintenance. The soil is shallower (less than 6 inches) and home to smaller, lighter plants such as mosses or wildflowers.

Both types of green roofs offer a variety of benefits including:

• Improved air quality as the plants absorb and convert carbon dioxide to oxygen
• Long lifespan - some green roofs in Europe have lasted more than 40 years
• Excellent insulation
• Cooled surrounding environment
  
  
  

The Urban Heat Island Effect

For hundreds of millions to perhaps billions of people living in and near cities, urban heat islands are a growing concern.

An urban heat island occurs where the combination of heat-absorbing infrastructure such as dark asphalt parking lots and road pavement and expanses of black rooftops.

They are then coupled with sparse vegetation, raises air temperature by several degrees Celsius higher than the temperature in the surrounding countryside.

Green building programs advocate the use of cool roofing to mitigate the urban heat island effect and the resulting poorer air quality (in the form of smog) the effect causes.

Clean, Cool, Green Roofs

By reflecting sunlight, light-colored roofs minimize the temperature rise and reduce smog formation.

In some densely populated areas, a quarter of the land cover may be roof surface alone.

To best combat the urban heat island effect, a combined strategy that maximizes the amount of vegetation by planting trees along streets and in open spaces. Also, by building green roofs, offers more potential cooling than any individual strategy.

Abating the urban heat island effect even has worthwhile effects in cooler climates. An LBNL study showed that, if strategies to mitigate this effect, including cool roofs, were widely adopted, the Greater Toronto metropolitan area could save more than $11 million annually on energy costs

Green Roofing... More Than Vegetative Roofing!

Your Green Roof Will:

• Reduce heating (by adding mass and thermal resistance value)
  
  
• Reduce cooling (by evaporative cooling) loads on a building by fifty to ninety percent
  
  
• especially if it is glassed in so as to act as a terrarium and passive solar heat reservoir — a concentration of green roofs in an urban area can even reduce the city's average temperatures during the summer 
  
  
• Filter pollutants and carbon dioxide out of the air which helps lower disease rates such as asthma
  
  
• Filter pollutants and heavy metals out of rainwater
  
  
• Help to insulate a building for sound; the soil helps to block lower frequencies and the plants block higher frequencies
  
  
• Installed correctly, many living roofs can contribute high energy savings!