One of the three rival concept plans for the West Kowloon arts hub deviates from the design brief laid down by the government and may go slightly over budget. The plans, presented to the board of the West Kowloon Cultural District Authority in a closed-door meeting yesterday, will not be made public until next month when the second stage of consultation starts. Each of the three architect teams had 90 minutes to introduce their work to the board at the meeting. A person familiar with the arts hub development said all three teams had made a remarkable effort in turning the site into a green place, complying with the brief that 23 of the 42 hectares of the arts hub area had to be open space. One of the three teams proposed a different phasing for the project - supposedly a two-phrase development to be completed by 2031 - which may result in a later final completion date, another person said. The design would also cost more than the budget. The government has set aside HK$21.6 billion for the construction of the arts hub, which will be home to 15 performing arts venues, a museum known as M+, residential buildings, and retail and dining facilities. The concept plans are intended to show the land use and layout of the cultural district as a whole, rather than the designs of individual buildings, which will be put up for competition later. The authority has commissioned Britain's Foster and Partners, the Rotterdam-based Office for Metropolitan Architecture - led by Rem Koolhaas - and local firm Rocco Design Architects to draft the master plans. 'Foster is safe and boring; Koolhaas is challenging the rule and unrealistic; Rocco Yim is adaptive and complicated,' planning activist Paul Zimmerman, said after receiving information from people familiar with the project. 'What is now important is to provoke a heated discussion about the merits and demerits of each option so the public can understand why the architects made their proposals and, in certain case, break the rules, which may not be a bad thing,' said Zimmerman, who led Designing Hong Kong, an NGO concerned with urban planning. A person close to the Foster design team said its plan would carry a local flavour, creating friendly streetscapes with shops like the old Yau Tsim Mong district and avoiding huge modern structures. The three plans are undergoing preliminary assessments on technical feasibility and compliance with statutory requirements, the authority said last night. The public consultation exercise will last until November and feature a roving exhibition across the city, guided tours and forums. The exhibition will showcase the three conceptual plans with models and animations. The public will be asked to comment on individual features of each option but not to make a choice out of the three, which is a decision to be made by the authority.