Buildings & Shooting

As I'm going through and re-ordering the rules, I've decided to pull some of the 'advanced' rules (Woods, Buildings, etc.) out into their own sections. In an effort to make the 'base' rules simpler and easier to follow. While doing that, I've had some interesting ideas on how buildings should be treated in regards to their own evasion/armor/toughness. For when you're trying to shoot the building itself, instead of the just the guys inside it.

Hitting A Building

All Buildings would be Evasion 1, plus whatever cover modifiers apply. The base of the building itself would function the same as a model's base in a standard LoS test. Which will make larger buildings automatically harder to 'hide' than smaller ones. Giving an Evasion range of 1-4.

The 'base' of a building would be its bottom edge.

If you're trying to put a round (or a grenade) through an window/door/hole, then the base evasion of that opening will be 6, minus 1 for each full inch of their longest dimension (including frames). The entire opening itself is treated as a 'base' for the normal LoS test.

The idea being that you may be trying to target an opening so that your high-explosive weapon can get past the wall and have a chance of hurting either the building itself, or everyone inside. Such as a grenade launcher that's trying to clear out a building full of grunts. Why shoot the grunt when you can lob a grenade right past him and hit everyone in that part of the building?

Building Armor Values

When you take cover inside a building, you hope that it's as solid as it looks. But you never know. That 'stone' wall might actually be plastic. Or, conversely, that flimsy 'wooden' structure might have been built to a much higher spec than most.

So the general idea is that buildings would be divided into 'light', 'medium', and 'heavy' classes. With a 4th class for 'bunkers'. You'd then roll the first time someone tries to shoot at the building, or anyone inside it, to see what the actual armor level is.

Light Buildings: D3 + 1 (Between 2 and 4)
Medium Buidings: D3 + 3 (Between 4 and 6)
Heavy Buildings: D3 + 5 (Between 6 and 8)
Bunkers: D3 + 7 (Between 8 and 10)

Building Toughness

We'd use the same building classes for toughness. Which would be rolled for the first time a weapon penetrates a building's 'armor'.

Light Buildings: D2 + 1 (Either 2 or 3)
Medium Buidings: D2 + 2 (Either 3 or 4)
Heavy Buildings: D2 + 3 (Either 4 or 5)
Bunkers: D2 + 4 (Either 5 or 6)

If you destroy a building, it becomes a ruin. The model can stay in place (with some sort of marker), but each occupant would have to roll some sort of Evasion test to get out, or be removed as a casualty. As a ruin, the building would follow the normal LoS rules, except that the visibility level of the LoS result would be raised by one (as for all ruins/obstacles). Making it impossible to hide behind, as hidden models would instead be merely concealed.

Once a building is a ruin, that's it. It can't be destroyed further.

Thoughts?