The state has disclosed a timetable for a project to turn a run-down juvenile detention center into an updated troubled-youth facility that would also include 180 rental apartments for low-income residents. It also updated the total cost estimate for the project.

The Department of Accounting and General Services projected that construction of the planned high-rise project on the 1.5-acre property at the corner of Piikoi and Alder streets could begin in late 2019 if the state Legislature approves a modest portion of the estimated $88.4 million price tag.

The cost of the project previously was estimated at just under $80 million, as reported in a March 9 story published in the Honolulu Star-Advertiser.

DAGS provided the estimates in a draft environmental assessment published last week. Earlier this month the state Judiciary, which controls the property and is partnering with the Hawaii Housing Finance and Development Corp. on the project, said it had no development timeline.

DAGS said the new juvenile detention and rehabilitation facility would be built in two or more phases, with an initial phase subject to funding approval by the Legislature this year. Gov. David Ige included $15 million for the project in his proposed state budget for the 2016-17 fiscal year; $1.5 million was previously approved in this year’s budget for design work.

If lawmakers provide the requested money, the state could begin soliciting proposals from private developers sometime between July and August, with a selection made in January. Another two years would be needed for the developer to execute a development agreement, prepare detailed plans, secure permits and obtain financing largely through the Hawaii Housing Finance and Development Corp., which expects to provide the bulk of the project’s financing through tax credits and its own funds.

If construction starts in late 2019 as projected, the affordable housing and an initial phase of the juvenile facility could be finished in August 2021, the DAGS report said.