In May 2009 Toronto became the first city in North America to require green roofs on all major new developments. Though in the works for three years, the new green roof being constructed at the Eglinton West subway station will be the first green roof on top of a subway. Constructed by Gardens in the Sky Inc, the green roof is visible from the Allen road expressway, which is a heavily-used north-south artery from the 401 highway. The green roof will be a 9,000 square foot garden constructed from sedum plants in removable trays. In addition to improving the aesthetic value of the area, the green roof will encourage bird and insect life and reduce heat in this heavily-used traffic corridor, according to Terry McGlade, president of Gardens in the Sky, Inc. The roof will cost about $25-$30 more per square foot than a traditional roof.