If you are creating a new development in Housebuilder Pro, the address will be a required field. This means that it should be impossible to create a development without an address. However if the address does need amending, this is straight-forward to do as an Administrator.
Simply go to your Admin menu in the top-right and click into "Developments" (Admin > Developments). Once there, select your chosen development. Now that you are viewing the details of this development, you can change the address simply by clicking into the text boxes, deleting what is already there and entering your new details.