Prevent fire damage to buildings, but allow on players?

Hello. Guys, how to disable fire damage on buildings, but allow fire damage on players?
Just helicopters and minicopters, breaking, burn buildings.
Also here can be attributed fire from explosive bullets.

Anyone answer?
Up.
Guys,  help Me. Very necessary. 
I have the same problem!Very relevant! Also, the plugin consumes a huge amount of server resources, how to fix it?
Comment out the 976 line.