The NSW government is moving ahead with its controversial plan to sell the Sirius building, launching an expression of interest (EOI) for the site at The Rocks, Sydney.

The government last year refused to give the brutalist social housing building heritage listing, against advice of the Heritage Council, paving way for the building to be sold for apartment redevelopment.

Property NSW chief executive Brett Newman said a two-stage competitive tender process would now be undertaken.

“The government is confident the draft site-specific State Significant Precinct State Environmental Planning Policy, in development by the Department of Planning and Environment, will ensure any future development on the site will consider the significant heritage of The Rocks precinct, including its design, balancing the best outcome for local residents and the wider community,” Mr Newman said.

“The new planning controls, which include the requirement of quality design outcomes, will materially enhance amenity in the area, and will ensure the maximum height of any building would be restricted to the height of the Sydney Harbour Bridge deck.

“We want to ensure the best value for the state is achieved for the asset while preserving the character of the area.

“Importantly, funds realised through the sale of the site will be reinvested by the government in new social housing across the state.”

However, Save Our Sirius chair Shaun Carter has warned potential buyers that the site is under a green ban and that development would be frustrated.

“If you intend to buy the site and demolish the building, you will have trouble from the green ban and Save Our Sirius,” Mr Carter said.

“We strongly advise anyone interested in buying Sirius to work with us and the building’s original architect Tao Gofers, to preserve Sirius for state heritage listing. If you don’t, you run the real risk of trouble from the Green Ban, from Save Our Sirius, and from the people, cultural and heritage organisations that have been asking this government to find a better solution for Sirius.”

The organisation is calling for the building to be used for key worker accommodation.

The EOI is being conducted by Savills, with submissions taken until 28 June 2018.