It's just slanted bricks.
A brick that actually goes like a ramp, versus a wedge mesh they use that doesn't work like a ramp. It's a block but looks like a mesh so you can't climb it.
Oh, were you referring to the picture of Killhouse I had there for a few seconds? :P
If so, no. They're actually slanted, you could walk up them.
I set up kind of "braces" to keep it in alignment, and then had a brick so that I could hit play, have it drop (unanchored) with collision (but have it not turn in any other direction because it's blocked by the anchored braces) and have it actually fall into the other brick (and stopped from bouncing away or getting into a bad position with more braces )which was anchored without collision, then anchor and set collision on both. I also did that for the horizontal beams, which actually go directly through the other parts.
Ninja edit: and if you're referring to Facechild's house, yes, they have a mesh on them, they react like cubes.