We typically use 3/4" furring strips applied vertically (for horizontal siding) to provide an air space behind the siding.

The walls around the chimney are usually just furring strips or even plaster right over the brick.

On the exterior, we added a rain screen made of 1x3 furring strips over top of our water resistive barrier (#30 felt paper). 

I recently met with Jon Shahoian of Lapham Property Managemebt last week and got some good insights into what's currently happening in these markets (FYI: rent control requirements/restrictions in Oakland will get increasingly onerous fur investors).Feel free to message me if you'd like to discuss further.

if using as a shim, there are easier ways to fur the wall out.Concrete board is porous and will absorb water. 

Think ,insulating, attaching furring to the interior for drywall, limited design parameterers, running ductwork, and mechanicals, asthetics, etc.

The shed fur can get sucked up into the furnace filter.

The front door is secured but there is a dog STUCK on the side the chain appears to be stuck on the bottom of his body and grown over with fur.

We'll fur out the wall next to the 6" post on this end to make it look right.

I believe the best way to rectify that is to run furring strips (might need to use 2x2s) and then either drywall or ceiling tile.