"A demolition that is planned as part of a covert operation to fit a narrative of events that attributes the total destruction of the building to a different cause (such as a jetliner crash and consequent fires) has a very different set of requirements than a demolition that is planned to legally remove a building in an urban setting. An examination of the technologies of energetic materials and wireless detonation available to insiders who had the means to coordinate the attack of 9/11/2001 suggests plausible scenarios by which the Twin Towers and Building 7 might have been subjected to controlled demolitions on 9/11/2001." - Source: http://www.911review.com/means/demolition/covert.html
The demolition expert in the video above does not think the Twin Towers were controlled demolitions due to their unconventional nature, but again this goes back to this being a covert operation, visit this link for more info. And despite claims to the contrary, he is quite sure WTC 7 was a demolition. Perhaps the more conventional nature of WTC 7's demolition can be explained by evidence that indicates 10:45 a.m. was the originally planned demolition time.