Particle system emitting upside down I am doing a Blender tutorial from Blender Guru on How to Build a City (https://www.youtube.com/watch?v=XCEN0qQOsIA) and I'm around the 30 minute mark where you insert your buildings as a group particle system. Many problems arised once I did so, for starters the buildings were emitting the wrong side of the plane (through the bottom), I fixed this. The buildings were also still overlapping even after I unchecked random, I fixed that as well. Now there's only one problem I can't seem to fix. The particle system of the buildings is emitting the proper way (upwards out of the plane), but they are still upside down (on themselves). Picture down below (first picture shows the top, where the entrance is, the second pic shows the roof with all the addded details on the plane that I'm emitting my particles from):





I've tried messing around with the majority of the particle settings but an't seem tto figure it out, the closest thing I could get was under the rotation tab and messing with the phase, but thiss turns the particles around the plane, not on itself. Any help would be appreciated! Thanks!
Ok I took a look at your file, You had to fix the rotation of two things. 


Change the rotation for the particles to Global Z
Go back to your other layer and rotate the group as shown in the image
You had the pivot point at the top of all your buildings, So Blender assumes this is where the building should start. You need to select each building in edit mode, then select the bottom face, hit Shift + S and choose move cursor to selected. Hit tab to go back to object mode and on the left tool bar change pivot point to 3D cursor. 


You need to do this to every building in the group.

 



Or you can just use the fixed blend file.