Building several hundred affordable rental apartments on state land in the Liliha- Palama area is now likely 15 months or more away from getting started, pushing back construction from what had been an anticipated start late last year.

The new estimated timetable for the public-private project initiated by the Hawaii Public Housing Authority for its 6-acre office campus at 1002 N. School St. was included in an environmental impact statement preparation notice published by the state Wednesday.

The notice indicated that HPHA and its nonprofit partner have yet to determine how many homes will be developed and at what rental rates. The nonprofit developer, California-based Retirement Housing Foundation, also has yet to sign a development agreement.

“We are at the very early stages of the development and still in the community engagement process,” Sarah Beamer, a housing planner with HPHA, said in an email Wednesday. “The redevelopment is a great opportunity to revitalize and modernize the site and the surrounding neighborhood, and create more affordable elderly rental housing, as well as a stronger and safer community.”

The planning and permitting work that still needs to be done reflects the complicated nature of large-scale affordable-housing development in Hawaii, where high construction and land costs have helped create an acute shortage of low-income housing.

A 2014 report from the Hawaii Appleseed Center for Law and Economic Justice projected that by 2016 the state would need close to 20,000 new homes for low-income residents. Nowhere near that number was produced.

HPHA in 2015 had about 12,000 households on its waiting list, and a five-year goal to develop 10,000 new public housing units.

To help achieve its goal, the agency sought competitive proposals from private developers in January 2015 to redevelop its headquarters site, which includes 14 temporary one-story office buildings and was viewed by the agency’s board as an inefficient use of state land.

The plan calls for up to 1,000 rental homes with a mix of affordable and market-priced units along with replacement office space for the agency, 10,000 square feet of retail space, 34,000 square feet of community/multipurpose space and parking. The city’s height limit for the site allows six- or seven-story buildings, though exemptions can be made for affordable-housing projects.

Hakim Ouansafi, the agency’s executive director, asked developers to be creative with low-cost, nontraditional concepts such as micro-units, used shipping containers and prefabricated modular apartments.

“We’re not interested in the 400-square-foot type of housing, but we’re trying to secure a very creative design,” he said in announcing the opportunity more than two years ago. He also expressed a goal for construction to start by late 2016.

HPHA’s board selected Retirement Housing for the project in June 2015.

To help shape a master plan, HPHA and its partner held several community meetings and workshops last year and in January.

Beamer said that initially the goal was to build as many as 2,000 rentals, but community input led Retirement Housing to limit the plan to 1,000 homes.

To date, no decision has been made regarding who the homes would serve — families, seniors or a combination of the two. Rental rates and income limits for tenants also have not been determined.

The environmental notice said HPHA and Retirement Housing are considering three mixes: 600 family units and 400 senior units; 400 family units and 600 senior units; or 800 senior units. There could be other alternatives.

“We are open to all alternatives, based on what the community wants, and what the EIS states we are able to provide,” Beamer said.

Another community meeting to present an update on design plans is tentatively slated for Oct. 18 at the agency’s offices.