Sydney's city and northern skyline are to alter once more with the construction of an office, residential and possible hotel towers on top of the new Sydney Metro stations.

The new sites are part of the NSW government's $20 billion Sydney Metro scheme, which will deliver a new train network across the metropolitan area.

In Pitt Street in the CBD, plans are understood to include two buildings: one a 47-storey mixed-use (potential hotel), and a 65-storey residential.

At Victoria Cross Station in Miller Street, North Sydney, there is one building, up to 40 storeys, with commercial offices and integrated retail on the ground level.