switching origin of dupligroup on empty from world center to some other pivot

I have a model of a city based on replicated buildings.
Every building is in it’s own group and then it is dupligrouped on the empty.
City is based on empty objects with different buildings.

When I use a dupligroup method on empty, the real object must be on the center of the world to be placed accordingly. I have a lot of buildings (around 70 and will be more) and when I place them all in the center, editing them is real pain.

Is there any way to switch from world center to pivot of the object and dupligroup on the empty?
Or make another empty to be a group pivot for it, and then dupligoup it?
Or any other solution similar to this one?
(so that I have all the buildings on one layer next to each other for easy editing)

Set cursor where you want origin point of the group, select one of your group object, go object tab > groups, right side is black down arrow > set offset from cursor.

WOW that is so cool, and it works for whole group selection too :smiley:

Realy Big Thanks