basicly want to know if i can increase the radius around a base so others cant build within a very short distance of each other.  i dont want ppl building right across roads from each other . if this can be done could some one plz find where i would find the setting for this or if it is a plugin that does it .

There is a plugin called "Cupboard range" which stops building within cupboard radius but does not say how large that radius is,