Urban areas are getting crowded and space comes at premium. If you are planning to shift to a big city like London, Paris or New York open spaces are either too expensive or not present at all. This has led to the architects planning pools for swimming exercise on roof tops. This is a challenge for architects.
Water is a natural corrosive and also has weight which has to be considered while installing swimming pool on roof tops. Otherwise it could end up in a disaster. State of the art technology is used to make the shell of the pool. This is the most important structure as a pool on roof top requires a strong base as well.
The engineering come to fore in giving more depth with less water volume. Weight is a concern at the top. The advantage of a roof top swimming pool is that the cleaning is less-frequent, and purification is easy. Gravity saves a lot of effort here. Just an outlet pipe is used to drain the water periodically.
The pool is best made in a single shell, so that failure due to leakage is minimized. The installation does cost but is worth it. You would want a pool even when you do not have the luxury of backyard space. I would want to experiment with this new technology in my flat at London. It is worth the cost I think.