BLUEPRINTS for the world's tallest building have been created by architects working for the MTR. The 97-storey Kowloon Landmark Tower would be a dramatic silver spike soaring more than half a kilometre into the air above the Kowloon airport railway station. At 574 metres, it would be comfortably taller than the present record holder, Kuala Lumpur's 452-metre Petronas Towers, and 14 metres clear of the proposed 560-metre Grollo Tower in Melbourne. The tallest building in Hong Kong now is the 374-metre Central Plaza. The Mass Transit Railway Corporation said the commissioning of blueprints was 'strictly a technical exercise'. Any decision on construction would be in the hands of a property development consortium which had yet to be selected. The MTR's town planning adviser, Chris McCarthy, said the building was 'still way over the horizon'. He added that the design was commissioned to determine whether the building would fit in with the rest of the site. The tower would be the last of seven phases of development for the site. Mr McCarthy said the first step - choosing developers - would take place in two or three years. American architects Skidmore, Owings and Merrill of Chicago - the designers of Chicago's Sears Tower - were hired to make the blueprints. 'For all its size and complexity, Landmark Tower will be remarkably cost-effective,' they said. The Town Planning Board approved outline plans for the site, including a tower up to 376 metres, four years ago. Mr McCarthy said any higher structure would therefore require new approval. But a paper presented this week at the Fifth International Conference on Tall Buildings in Hong Kong said there was an underground 'valley' under the site which caused problems with foundations. But engineers had found a way to avoid the valley and lay the foundations in solid rock. The building's total floor area of 230,000 square metres would be equal to 31 football pitches. The first 27 floors would be a 600-room luxury hotel, with a pool on the 27th floor. Above would be office space, with floors 92 and 93 set aside for two restaurants and an observation deck served by the world's fastest lifts. Dedicated firefighters' lifts could reach any floor in a minute. Other safety features would include pressurised stairwells to prevent smoke entry. The architects said their tower would be 'a truly unique world-class landmark for Hong Kong and China'. 'The silvery glass planes create a facade that constantly changes with the sunlight and direction of view,' they said. It would be heavily illuminated at night.