Green Roof

In May 2012 the City of Roanoke installed a green vegetated roof on the Noel C. Taylor Municipal Building.

Purpose
The 6,700-square-foot green roof has 2,900 square feet of plants with 13 varieties of water-conserving sedum plants.

The roof system also has a rainwater harvesting system, which includes 6500-gallon tanks for watering the roof via automated irrigation system.
A building in downtown Roanoke with a green roof
This system provides plants with adequate water as needed, with a solar powered weather station that calculates the evaportranspiration value, a calculation indicating watering needs.
Cost
The plants cost approximately $58,000, and the total cost of all materials, including plants and materials associated with installation, mulch, and rainwater harvesting system was approximately $123,000. We used City employees to install the roof, which mitigated labor costs. Anticipate the green roof will increase the life of the existing roof membrane from 20 years to 60 years.

Benefits
  • Reduces the amount of storm water runoff by 44 per cent per one inch of rain
  • Reduces heating and cooling loads by increasing insulation
  • Reduces noise transmission
  • Creates an attractive roof that helps sustain a habitat for butterflies, insects, and songbirds
  • Triples the life of the roof