Today, many buildings collect rainwater and then use it in various ways, such as giving water to plants. Do you think such buildings will become more common in the future?

I think many buildings will collect rainwater in the future.I have two reasons why I think so.
To begin with, collecting rainwater makes buildings little cost to use water.Buildings can spend more money instead of water cost.
In addition, collected rainwater may help us when a disaster happen. For example, collected rainwater can boil food and be used for taking a bath.
For these reasons, I think It will become more common that buildings collect rainwater in the future.

4 I think such buildings will become more common in the future. First, by making use of rainwater, a building owner can reduce the cost of water used from the water supply. For example, rainwater can be used for washing cars and for growing plants in gardens. Second, collecting rainwater can be useful in times of disaster. Due to damage to water pipes, supplies of water are sometimes limited. In such cases, rainwater will help until normal conditions return. Therefore, I think buildings that collect rainwater will become more common in the future. (*上記はあくまでも解答例です。)