CN Tower still world's tallest: Guinness

A wrinkle in semantics means Toronto's CN Tower will retain its place in the Guinness Book of World Records — but not as the world's tallest free-standing structure.

The 553-metre structure will now be known as the world's tallest tower, said Craig Glenday, editor-in-chief of Guinness World Records.

The tower lost the title of the world's tallest free-standing structure in 2007 when the Burj Dubai — a hotel, residential and commercial building in Dubai, United Arab Emirates, still under construction — surpassed the Toronto structure in height.

When it is completed the Burj is expected to be over 818 metres high.

But classification rules, as defined by an organization deemed the authority on such matters, suggest the CN Tower should be categorized as a communications tower, said Glenday.

"I can confirm that the Toronto icon will retain its record, as a tower is defined by Guinness World Records and the Council on Tall Buildings and Urban Habitat as a building in which less than 50 per cent of the construction is usable floor space," he said in a Friday statement.

The Burj, by this definition, is not a tower.

The new record will be made official on Monday, when Guinness officials will present a certificate to the CN Tower at Horizons restaurant, located 346 metres up the building.