Good morning. Today we'll continue our discussion on urban planning, focusing on the concept of 'green roofs.' Green roofs are rooftops covered with vegetation, and they offer multiple benefits. First, they reduce stormwater runoff by absorbing rainwater, which helps prevent flooding in cities. Second, they improve air quality by filtering pollutants. However, their installation cost is relatively high, ranging from $15 to $25 per square foot. Despite this, many cities, including Toronto and Singapore, have implemented policies to encourage their use. Now, let's consider a case study. In Toronto, a pilot project on a community center showed that the green roof reduced the building's energy consumption by 10% in summer. But, interestingly, the energy savings in winter were minimal, only about 2%, because the insulation effect was less significant. So, while green roofs are beneficial, their economic viability depends on climate and building design.
❓ Theo bài giảng, thách thức kinh tế chính trong việc triển khai mái nhà xanh là gì?