Adding a bathroom - do I need a septic permit? (house, rated)

[KFran]

We would like to add a bathroom addition to our 3 bedroom 1 bath house in unincorporated Wake County. We are not adding another bedroom, just a bathroom. Does anyone know if we need a septic permit for this? From what I've read at wakegov, you need one for another bedroom, but it doesnt say anything about another bathroom. We would connect our extra bath into our current septic. Our current septic is probably from the 1950s or 1960s. Anyone have experience with this?

Thanks!