The Port Authority approved a multibillion-dollar plan Thursday to replace the dilapidated 65-year-old West Side bus terminal, with a goal of deciding on a final design by next fall.

Thursday’s vote authorized the Port Authority to hold an international design competition and choose a winner by September 2016. The project is expected to cost from $7 billion to $10 billion and take several years to complete.

The board endorsed a site one block west of the current terminal at 8th Avenue and 42nd Street. Entrants in the design competition will be allowed to come up with alternative sites, officials said Thursday.

The Port Authority will also hire an outside consultant to study ridership projections over the next few decades and review the terminal project in the context of other transit projects in the region.

Officials plan to sell air rights at the current terminal and the resulting condos, commercial sales and rent would pay for about two-thirds of the cost for the new building, NBC reported.