Manchester's First Green Roof
now sits on top of City Hall's Connector building.
This UNH Cooperative Extension Initiative combines new technology with plants to deliver many benefits to the building below and to our overall urban environment.
Most rain that hits a conventional commercial roof flows off, carrying with it heat and particles. As the runoff hits the ground below, it picks up more pollutants: gasoline, oil, antifreeze, sand, and heavy metals that end up in local streams and rivers.
As the amount and velocity of rain increases, stormwater runoff can cause flooding, and overload the wastewater treatment plant, which then dumps untreated sewage directly into the Merrimack River.
The green roof absorbs up to 95% of a 1-inch rainfall, allowing it to percolate slowly through the plants and soil. Much of the water evaporates and what runs off is delayed, giving sewer systems time to recover.
Plants on the Green Roof
The planting beds behind this sign contain the same plants growing on the roof, many of which can be found in the gardens around town.
The plants and soils in a green roof serve many functions, which include:
Reducing the energy needed to heat and cool the building below.
Saving money by extending the life of the original roof.
Lessening the risk of flooding and overflowing sewers.
Providing habitat for butterflies and other pollinators.
Filtering air pollutants, improving air quality.
Installing the Green Roof
The GreenGrid System uses 4-inch deep recycled plastic containers filled with a lightweight growing mix and planted with perennial plants that thrive in hot, dry, and windy rooftop conditions.
Installation took two hours. After covering the original asphalt roof with a slip sheet, the installation team lifted the pre-planted containers into place.
Unlike some green-roof systems, the GreenGrid System doesn't require additional roof construction or design.
For more information about Manchester's green roof, including updates on temperature monitoring and pollutants absorbed by plants, go to: www.ManchesterNH.gov/CityGov/dpw/EPD/greenroof.html [does not work]
For specific information on the GreenGrid System used here, go to www.greengridroofs.com
For more information on green roofs, go to http://extension.unh.edu/FHGEC/greenroof.htm [does not work]
No Manchester tax dollars were used for this green-roof project. All funding came from grants and private sponsors:
UNH Cooperative Extension in partnership with the N.H. Division of Forests and Lands and USDA Forest Service
McLane Law Firm
Manchester Development Corporation
Lavallee Brensinger Architects Fund of the N.H. Charitable Foundation, Manchester Region
Weston Solutions, Inc.
N.H. Dept. of Environmental Services
Anonymous Fund of the N.H. Charitable Foundation
SEPP - Enterprise Fund, administered by the City of Manchester Environmental Protection Division
City of Manchester
Greater Manchester Chamber of Commerce
[Photos of various green roof plants]
Erected by City of Manchester.
Topics. This historical marker is listed in these topic lists: Charity & Public Work • Environment • Horticulture & Forestry.
Location. 42° 59.455′ N, 71° 27.813′ W. Marker is in Manchester, New Hampshire, in Hillsborough County. Marker is on Market Street east of Franklin Street, on the left when traveling east.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Brigadier General John Stark (a few steps from this marker); City Hall (a few steps from this marker); Manchester NH War Memorial (approx. 0.2 miles away); Manchester NH Civil War Memorial (approx. 0.2 miles away); Manchester NH World War II Memorial (approx. 0.2 miles away); Manchester NH Iwo Jima/Rene Gagnon Memorial (approx. 0.2 miles away); Manchester NH Victory Park War Memorial (approx. 0.2 miles away); The Mill Girl (approx. 0.2 miles away). Touch for a list and map of all markers in Manchester.
Regarding Manchester's First Green Roof. Marker has limited historical information but highlights the first green roof in Manchester.
Also see . . .
1. About Green Roofs. Website homepage (Submitted on May 23, 2018, by William Fischer, Jr. of Scranton, Pennsylvania.)
2. Green Roofs. This Old House website entry (Submitted on May 23, 2018, by William Fischer, Jr. of Scranton, Pennsylvania.)
3. Green Roofs. Government Service Administration website entry (Submitted on May 23, 2018, by William Fischer, Jr. of Scranton, Pennsylvania.)
Credits. This page was last revised on May 19, 2022. It was originally submitted on May 23, 2018, by William Fischer, Jr. of Scranton, Pennsylvania. This page has been viewed 209 times since then and 79 times this year. Photos: 1, 2. submitted on May 23, 2018, by William Fischer, Jr. of Scranton, Pennsylvania.