雅思听力

🎧 Listening Transcript

Good morning, everyone. Today we're continuing our series on urban planning. Let's consider the concept of 'green roofs'. A green roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems. While the initial cost of installing a green roof is higher than a traditional roof, studies show that it can reduce energy costs by up to 25% in summer by providing natural insulation. Moreover, green roofs can extend the lifespan of the roof membrane by protecting it from UV rays and temperature fluctuations. However, one significant challenge is the structural weight, as the saturated soil can be very heavy, requiring additional building support.