Rich Listers Shesh Ghale and Jamuna Gurung have sold a five-level standalone office building in the Melbourne CBD that will a require a minimum $2-$3 million investment by the new owner, highlighting the challenge for owners of lower-grade office stock in a declining market.

Mr Ghale and wife Ms Gurung sold the 376-378 Bourke Street building leased to education provider Queensland Institute for about $14.5 million to Collective Capital, an investment group headed by former valuer and asset manager Nicholas Thompson.