From my office on the 21st floor of a building in Vancouver, BC two parking garages in the process of being demolished are visible. A third is just out of view a few more blocks away.
One of these structures is being taken down by a team consisting of an excavator with a jackhammer, an excavator with a claw and a man holding a hose. The jackhammer punches holes in the cement, and the claw breaks it up and allows it to fall to the floor below.
A couple of blocks away a different approach has been taken where it seems they are cutting the concrete into chunks and then lowering it down with a crane.
We've all seen the news clips and YouTube videos of demolition via pyrotechnics.
Are there other approaches?
Presumably, demolition by explosion requires a large amount of upfront time, effort and engineering skill as detailed in this answer. All of this culminates in one significant event, the detonation, and then substantial cleanup.
The jackhammer and claw approach seems like it is at the opposite end of the spectrum and requires relatively little skill and lots of labor to proceed at an excruciatingly slow and noisy pace.
Cutting and lowering seems to be in the middle with more expensive machinery to cut and skilled operators required. It also seems to move very slowly but anecdotally seems to have none of the noise associated with jackhammering.
What does the decision tree/matrix look like for picking an approach? Surely cost plays heavily into it but watching these sites move forward day by day I'm curious as to how two very similar sites in the same city (so permitting is presumably similar) chose different approaches and neither chose to use explosives.