The state on Friday released a 200-page response to a commission of inquiry which examined child sexual abuse in government institutions.
The response detailed a swathe of legislative and child safety reforms to be implemented in three phases ending mid-2029.
The final 191-recommendation report of the inquiry, made public in September, found Ashley Youth Detention Centre posed a "live and current" abuse risk.
It called for the centre to be closed "as soon as possible".
The government two years ago pledged to shut the centre by the end of 2024, but more recently flagged a longer timeline as part of broader youth justice reform.
The government response said a master plan for the proposed new facility north of Hobart would be open for public consultation in the second half of 2024.
"This will inform the development application to council, which is expected to be lodged in 2025, with construction to commence soon after," the response says.
The inquiry lists the closure of the centre as a medium-term recommendation, to be completed by July 2026, something the government says it will achieve.
"Transforming our government institution, our systems, our culture and rebuilding trust will take time, investment and a commitment to deliver," Premier Jeremy Rockliff said.
"But the way forward is clear and it is our highest priority."
In line with the inquiry's recommendations, the response commits to a review of custodial stays at the centre by July to determine whether they align with sentencing orders.
Former national children's commissioner Megan Mitchell AM will evaluate the centre's internal policies by July.
The government plans to implement more than 80 per cent of the inquiry's recommendations with phase one ending July, 2026.
Among other recommendations to be implemented by July, the government will review legislation to ensure apologies can be made without accounting to an admission of liability.
The inquiry held eight weeks of public hearings last year but said it was hampered from delivering some misconduct findings because of complex legislation.
It examined youth justice, education, out-of-home care and health with a particular focus on Ashley and the Launceston General Hospital.
It was told of abuse and neglect at Ashley and a lack of government action despite more than a dozen reviews and reports pointing to issues over decades.
It also detailed missed red flags by government and police in relation to a male nurse at the hospital who worked on a pediatric ward for nearly 20 years before taking his own life in 2019 when charged with child sexual abuse offences.
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