Which still doesn't answer the question. That's like me saying: "It's bigger than the rest of the buildings in Calgary".
Okay fine I'll try to be a bit more helpful, instead of just trashing Alston.
From Wikipedia, and it is a lot of speculation (Shad likely has a better source):
The EnCana Office Complex (also referred to as "EnCentre") is a planned highrise complex being built in downtown Calgary, Alberta by EnCana Corporation[1], North America's second largest natural gas producer. Early schematic design concepts suggest that the project may consist of a complex of towers (perhaps two or more) over two blocks. The tallest of these towers could be 60-stories tall, which would make it taller than the current tallest tower in Western Canada, the Petro-Canada Centre (also in Calgary). Conflicting reports now suggest that it will be one single tower around 70 stories tall and possibly over 1000 feet(305m)making it the tallest building in Canada. Other sources suggest a two tower complex spanning the entire surface of two blocks, with a second tower of 40 to 50 storeys connected at 6th storey level over 6th Avenue[2].