Tim,

This question is referring only to additional property that is added during the policy term. 

If - by adding additional property - the status of the named insured changes; liability coverage would be subject to change also.  For example:  I own a business and decide to lease an additional warehouse.  The CGL covers the additional warehouse against liability claims. However, if when I acquire the additional warehouse space, I take on a partner to help with the extra workload - I have 90 days coverage from the time I acquire the partnership and the loss must have happened after the partnership was formed.  

Does this answer your question? - Jan