So many things happen inside of buildings and we spend so much time inside of buildings, but we learn to fight with guns out in the open. But fighting in a building, checking your house for a possible hostile, intercepting the bad guy before he gets to your kids in a way that lets you end the fight before he starts it, fighting your way out of a problem--all of this is different than fighting in the open. It needs some different skill-sets.
Also, this is pretty much a pure skills class. Because of the facility we'll be in we can do some actual FOF, but there will be no live fire. So you won't have to bring in a bunch of ammo. Airsoft only. And a focus on skills and time spent on developing skills.
Well worth the time and expense to get this kind of knowledge.