Tired of living in the same location but don't want to leave the house you love? That wouldn't be a problem if architect Felipe Campolina had his way. The Brazilian architect has designed a concept for a home tower consisting of portable, stackable   apartment units, which he says opens up new possibilities for ways of living in the city. His design would allow owners to take their home with them when they travel -- whether for a weekend away or for longer periods, he said. The mobile home tower project is at the concept stage, and it could be years before it is built, if ever at all. But if it is realized, it would offer an eco-friendly solution to living in urban areas, Campolina said. "We have enough technology to build with fewer materials and minimize   the impact on nature," he said. His vision would call for units with a green roof and walls and a system for recycling water. The tower, whose first floor would be built nine meters above ground, would also make it possible to save space in thickly populated areas. "It is designed to facilitate   its application in dense urban centers, where space is very limited," he said. Still just a concept, Campolina -- who designed the building for architecture journaleVolo's Skyscraper Competition -- said with enough public interest, it just might become a reality one day. Which of the following is TRUE about the home tower?
All its walls will be painted blue. It will have a waste paper recycling system. It will be made of recycled rubbish. It will do little harm to the environment.