The police station in Lyttelton is the latest old building in Canterbury which will not be repaired, following the February earthquake.
The station was built between 1880 - 1882 and opened in 1882.
Inspector Malcolm Johnston says engineering investigations showed it would be uneconomic to repair the station.
The estimated cost of repairs was at least $1.5 million, significantly more than the cost of a new station.
Inspector Johnston says Friday's earthquakes caused significant additional damage and would have increased the cost.
He says the police may eventually share a facility in the town with the fire service and St John Ambulance.
Lyttelton has lost many old buildings since the quakes began.
Police have been working out of a garage next to the station since February and a portable building was recently added.