I am involved in a project where a large concrete structure is being expanded. The rebar for the existing structure is being tied together with the rebar in the addition. There is no changes to the main electrical service. The new addition will have new electrical wiring for lighting and miscellaneous loads. The existing structure already has a UFER ground as part of the GES. Is it required that the new addition have another UFER ground that is run back to the main service? With the rebar all tied together between the structures isn't the new addition bonded to the existing UFER ground?