A spokesman for RNZ said it was decided to take office space in the same building after a review of property options in the city.
"Several alternative options were shortlisted before a final decision was made."
The shift from its current office on Cashel St will happen this calendar year as its old lease is set to expire.
Approximately 15 RNZ staff will move to the new building.
The spokesman would not say if they will be operating on separate floors.
"There is no suggestion that links can be drawn between RNZ and TVNZ being in the same building. It is completely coincidental but that location happens to be the best option for RNZ."
A press secretary for Broadcasting Minister Kris Faafoi said he was unaware of the government-owned companies' plans to move.
It follows confirmation last year that the Government plans to create a new public media organisation to replace RNZ and TVNZ within three years.
A business case into the plan is under way but if approved, the new entity could be in operation as soon as 2023.
