IELTS Reading Lab

Paragraph A. As cities grow, finding space for parks and gardens becomes increasingly difficult. Buildings, roads and car parks take up much of the available land. In response, some urban planners have begun looking upwards rather than outwards. Rooftop gardens, which turn unused roof areas into green spaces, are becoming more popular in cities around the world. They can contain flowers, trees, vegetables or even small areas where people can relax.

Paragraph B. One important benefit of rooftop gardens is their potential to reduce urban heat. Concrete and asphalt absorb energy from the sun and release it slowly, making built-up areas warmer than nearby rural locations. This phenomenon is often called the urban heat island effect. Plants provide shade, while the release of water vapour from leaves can help cool the surrounding air. Green roofs may also insulate buildings, reducing the amount of energy required for heating and cooling.

Paragraph C. Rooftop gardens can also support the environment in other ways. Their growing medium absorbs some rainwater, slowing the movement of water into city drainage systems. This can reduce the risk of local flooding during heavy rainfall, although the amount of water retained depends on the roof's design and the weather. In addition, gardens may create habitats for insects and birds. Even relatively small green spaces can provide food or shelter for some urban wildlife.

Paragraph D. Food production is another possible advantage. Some buildings have gardens where residents grow herbs, tomatoes and other vegetables. These projects can bring neighbours together and help people understand where their food comes from. However, rooftop farms cannot usually replace conventional agriculture. The amount of food they produce is limited by the available space, sunlight, water and the types of plants that can grow successfully.

Paragraph E. Despite these advantages, rooftop gardens are not suitable for every building. Soil, water and mature plants can add considerable weight, so engineers may need to check the building's structural strength before installation. Waterproofing, drainage and safe access must also be considered. Installation and maintenance can be expensive, particularly when a roof requires significant improvements. For these reasons, successful projects usually involve architects, engineers, building owners and gardeners working together from the beginning.

Paragraph F. In the future, rooftop gardens may become a more familiar feature of urban planning. Some local governments encourage green roofs through grants or building policies, while businesses may install them to improve environmental performance. Nevertheless, experts point out that rooftop gardens should complement, rather than replace, parks and other public green spaces. Their greatest value may come from combining several benefits: cooler buildings, better rainwater management, opportunities to grow food and more nature within crowded cities.