It is a common misconception that the Quake engine, and by extension its derivatives like Darkplaces, do not allow destructible architecture or objects, simply because Quake lacks them. That, however, was not an engine limitation, but a deliberate choice made by the level designers, who decided not to implement a feature that the engine is perfectly capable of performing.
Ego Enforcer features breakable architecture and objects, which I implemented in QuakeC (so the original executable is not modified), making use of all the unused bits in the spawnflags variable. All I had to do was recycle the code that generates gibs when an enemy is blown up. I applied it to the function that manages func_buttons, adding a routine that reads the value of spawnflags and uses it to calculate which type, of how many, models representing fragments must be generated and thrown around.
Now that I created the appropriate models (representing fragments of metal, wood, stone, glass, and ceramic) and the routine for the desired behavior, all I have to do whenever I want to create something that can be blown up is to set the correct value of spawnflags to a func_button (and explicitly specify its origin), which will behave as destructible architecture in game.
