The voxels are always the same size. They just become disconnected. That makes them look smaller.

It is voxel based. I dont know how exactly this works, but I guess it breaks up surfaces into tiny voxels if needed. And then it pulls more processing power from your system to render the scene.
But that is only my guess. Because without the burned down houses I can play that level. Not with the best performance, but it is not a hefty slideshow ^^

Wow. Ok. Yeah. I guess fire is quite demanding.

Yea, three houses burned down entirely and I have a hefty slideshow.

Really? Only three time share cabins? That's one weak computer.

@Ctoycat:
I have to admit, that I can only burn up to three houses down in that lavel. After this the level becomes unplayable X D
GPU is a 1080. Nothing more. Sooo, yea, isnt much.

my computer: laggy to begin with
DOES THIS: ba-dum-CRASH