The Chinese University admitted yesterday it planned to cut down at least 100 trees to build two new small residential colleges. But pro-vice-chancellor Ching Pak-chung said double that number of new trees would be planted and rare or special trees would be preserved. Two tennis courts will also be demolished to make way for the colleges, being built to cope with a new four-year degree structure to start in six years. The Morningside and S.H. Ho colleges will be fully residential with communal dining, and space for 300 and 600 students respectively. They will be built side by side on 13,200 square metres at the north of University Avenue in the campus, next to the Chung Chi College, one of the university's four existing units. Professor Ching also countered criticism that the land is being taken away from Chung Chi College. He said the site, consisting of a slope, the tennis courts and the university's estates and maintenance office, was part of the central campus, not Chung Chi College. The estate's office would be moved and the building refurbished to become part of the S.H. Ho College. Six new tennis courts would be built nearby instead to compensate for the loss of the two courts. Professor Ching said the government would not allocate extra land for the colleges so the university had to find the space on campus. The trees will be cut down to build four residential blocks of four to 10 storeys, but Professor Ching said that as well as planting more trees, the university would alter the design of buildings if necessary to protect rare or special species. 'We plan to spend more in order to make the colleges greener - there will be less parking space but more trees.' Environmentally friendly building materials would also be used, together with solar panels to generate backup power. No timetable and designs were confirmed for the construction, but Professor Ching hoped the colleges would be ready before 2012. Student union external vice-president Li Yiu-kee said the university never consulted students and the union on the plan, and he criticised its move to cut down trees for the construction. 'You can't compensate by planting more later - they are alive after all,' he said.