Behind the Green Roof
1 | Xavier’s green roof sits on top of the Hoff Dining Hall and creates an outdoor courtyard for Bishop Fenwick Place, the new residence hall.
2 | The roof is actually structured more like a large pot, with the grass, trees and shrubs
growing in a multilayered container. Sandwiched in between the vegetation on the top and the actual roof at the bottom are a layer of soil, a filtration cloth, a layer of drainage stone and a water barrier.
3 | The soil and grass retain water, decreasing the amount of stormwater runoff. However, due to the additional weight created by the collected water, the building under the roof has to be structurally enhanced.
4 | In addition to saving water, the roof is also a sound barrier, decreasing the intensity of outside noise by 40-50 decibels. In comparison, standard foam earplugs reduce outside noise by 30-40 decibels.
5 | If that weren’t enough, the roof acts as an insulation device, keeping the space underneath cooler in the summer and warmer in the winter. Thus, the building saves more energy than other buildings on campus and prolongs the lifespan of heating and ventilation systems.