The Mashantucket Pequot Museum and Research Center was built on the southern edge of the Great Cedar Swamp on a north-facing slope of the Mashantucket Pequot Reservation in Mashantucket, Connecticut. The facility was designed to interact with its surrounding environment and maintain the ecological integrity of the area by embracing the tree line and topography. Due to the large size of the facility (308,000 sq. ft.), the Tribe wanted a seamless transition between the museum roof and the adjacent swamp, a 500-acre wetland of significant historical and cultural importance to the Mashantucket Pequot community. The green roof is approximately 65,000sq. ft. and covers all of the permanent museum exhibits. The approximate cost of the green roof at the time of construction was $25.00 a sq. ft. and the estimated expense is $1.6 million. 

The green roof terrace is also used for educational and cultural purposes. Many of the plants incorporated into the terrace gardens are culturally important. Several “ethnobotany” gardens have been used to educate students about cultural traditions of native people and how different plants are used for food, medicine, and materials. The near term goal of the museum is to develop a root, herb, and berry garden on the green roof that will supply the museum kitchen with periodic and seasonal foods harvested locally and that will also be reflective of a traditional Native American harvest. The plantings on the terrace continue to change to suit the needs of the museum. Many indigenous plants and introduced ornamentals are currently planted. Some of the original plants used were: low bush blueberry, daylily, liatris, strawberry, bloodroot, wormwood, yarrow, bee balm, spearmint, peppermint, black-eyed susan, wild columbine, tansy, and sage.

The museum roof terrace will be used for a variety of purposes – as a gathering area for museum receptions, events, and (in the near future) a sculpture garden exhibiting the works of Chiricahua Apache artist Allan Houser. The terrace is accessible to the general public who use the space for meetings, lunchtime breaks, reading, playing, and demonstrations of traditional Native American games.

Approximately 12 inches of growing medium cover the museum’s green roof. Stratified layers of substrate were used to facilitate appropriate/suitable drainage and planting objectives for the green roof. A base of gravel was overlaid with coarse/medium sands. Local topsoil saved from the construction site was redeposited to serve as the principal growing medium. 

The green roof membrane is reinforced hot rubberized asphalt. All of the green roof areas have a double layer of insulation with an underlying water retention mat. 

The Tribe’s desire to install a green roof is a demonstration of their reverence for the land and conservation of resources. It was their expectation that it would reduce energy costs but there is no baseline with which to determine the relative energy savings. The excess water/storm water is channeled through ducts into a series of retention basins at the edge of the Cedar swamp and allowed to rapidly filter back into the wetland. 

Terrace maintenance staff recycles and composts grass clippings and uses environmentally appropriate fertilizers. The Museum terrace has drip irrigation on bushes and timed irrigation on each layer based on growing conditions. Drought resistant sod is used and a potentiometer measures water resistance in the growing media to determine irrigation cycles. Maintenance for the Museum’s green roof is minimal. Since completion 8 years ago, they have not experienced any problems. The only maintenance requirements involve landscaping. 

The Mashantucket green roof is an excellent example of how a green roof can serve as a place to preserve cultural traditions while at the same time upholding traditional beliefs in the sanctity of the land.