The controversial Sirius building on the edge of the Rocks is a step closer to demolition after the NSW government again declined to grant the brutalist former social-housing block heritage status and protection from redevelopment.

NSW Environment Minister Gabrielle Upton announced on Wednesday that she had declined to grant the heritage status, moving a proposal to demolish and redevelop it into a $120-million apartment redevelopment to completion.

"My role is to decide whether the building has aesthetic value and, if so, whether that value is such as to satisfy [heritage value] at a state level," Ms Upton wrote in a decision published on Wednesday. "While the Sirius building is distinctive, in my view, it is not a landmark worthy of state heritage protection."

The announcement comes after a previous decision by Ms Upton's predecessor not to list the building was overturned in the Land and Environment Court in July, after the state government was found to have "side-stepped" its obligation to consider the building's heritage value and misapplied the law.