This is a list of Security buildings in The Last Stand: Dead Zone.
Zombies tend to be attracted by concentrations of survivors, and compounds are no exception. Many survivors will not join a compound that they feel is unsafe, and those already part of it will be unhappy about the lack of safety, negatively affecting their morale. Security buildings like barricades will assuage their concerns, as well as make the compound easier to defend when the inevitable happens.
The current maximum Security rating, with all security buildings built and fully upgraded, is 273.