There are houses where you never find any loot in them. It's the green house with a little stair up to the elevated entrance, a similar red one,also with a stair leading up, and others.
example: http://cloud-3.steampowered.com/ugc/795186902396838963/A67716405E6B2431ABE79B67AC7B7A5825F60820/
The loot spawn is bugged and gliched below the houses's floor on the ground.
I found this out when I dropped a first aid kit in one of them, and suddenly it was gone. When i searched for it, my view gliched and I could see through the floor. There was my first aid kit! down on the grass ground beneath the house!
And also there was a can of beans and something else! The loot that should have spawned in the house just falls beneath it!
most of the houses that never seem to spawn any loot are houses which interior is higher above the ground, where you have to climb a small stair to get in.
Afterall, it means there is a shitton of loot on the server that noone ever picks up, this could easily add to the fps!
Please Devs check this out!