In this example i made system that takes input geometry as it exists in world space as whole (i just manualy separated planks and walls in two streams tho this is also done by naming groups previously so its also automatic)
Every wall is then splited into bricks, no matter the orientation and size of original wall and same goes for planks.
Each plank has its own constraint structure and then all planks have separate constraint setup to hold them all together.
Model in this example is not particulary made for destruction (it does have interpenetrating objects) and thats why it has some instability (some constraints break on in the beginning)
665 initial pieces of geometry,
14744 generated fragments (rigid bodys), bricks and wood splinters alltogether.
Simulation is fairly fast, it goes from 5 to 8 mins depending on solver settings (on Asus ROG laptop !)
Rendered with Redshift (about 2 mins per frame on Nvidia 960m, full GI brute force, sun lit + env, all shaders with glossy reflections)
Have fun with scene file !
SCENE FILE: https://arsa3d.wordpress.com/rd/
Barn model: courtesy of Stefan Devic
Some help with VEX: Dragan Najdenov