Revising Building Plans

I'm currently building a 3/3 house on the North side of the island.  My Question is once I have my plans and building permit can I make changes to the floor plan and add a balcony with no problem or do I need to revise and resubmit for approval?  I was told now that I have my permit I can make any changes I want. Not sure if this is true if someone can confirm this.

thank you