Posted 23 May 2017 - 09:51 PM
The best way, the only way that even now really looks good, is large scale model work, high speed cameras, and skilled pyrotechnicians. Really good pyro reduces the size of model that's required for good results.
One trick is to make an approximate model of the real building, paint it black or occasionally green, and blow it up while shooting it from a matched angle with the real thing. A bit of compositing later and you're in business.
Compositing stock footage may be feasible depending on the type of building, the desired style of destruction, and other factors.
Fully CG pyro is still, even now, often unsatisfactory.