 An extension towards Orewa in the north is being debated for the long-term future.It was originally expected to cost around NZ$500 million, although the success of the scheme has now sparked potentially more extensive schemes for between NZ$700 million and NZ$1.2 billion to at least Silverdale, with up to five tunnels and seven bridges, including a motorway flyover between Constellation and Albany stations.Plans in 2008 included additional stations at Rosedale and Redvale.