A long-delayed plan to develop about 800 affordable rental homes on state land in Kakaako has been cut in half to make room for a public elementary school that could become a prototype for compact urban school design on Oahu.

State Department of Education representatives along with the tentative developer of the high-rise project known as 690 Pohukaina publicly revealed revised conceptual plans Wednesday during a board meeting of a state agency that solicited competitive proposals to deliver affordable housing on the site more than three years ago.

The proposed change, however, has raised concerns among state officials over whether the modified plan conforms enough with the original request for competing private development bids so as not to make the request void or vulnerable to a challenge.

The Hawaii Community Development Authority, a state agency regulating development in Kakaako, solicited development proposals in 2012 for 2 acres of state land bordered by Pohukaina Street, Mother Waldron Park, Keawe Street and a low-income rental housing tower called Halekauwila Place.

HCDA’s board tentatively picked a plan by an affiliate of Ohio-based Forest City Enterprises Inc. over a competing plan from Australia-based Lend Lease.

Forest City proposed 804 rental apartments in two towers along with 35,000 square feet of civic space for state offices and library facilities, 4,400 square feet of community space and 30,000 square feet of commercial space for a restaurant, a small market, offices and other uses.

Now Forest City is proposing one tower with about 400 mostly moderately priced rental apartments next to a four-story elementary school. The change came after DOE pressed the developer and HCDA to provide school space in the project.

DOE had expressed concerns for several years about existing school capacity being insufficient to accommodate people moving into new residential towers rising in Kakaako, and for more than a decade had envisioned a school on the 690 Pohukaina site that long ago was home to Pohukaina School.

A few years ago, two elementary schools serving Kakaako — Royal School and Queen Kaahumanu Elementary — were at capacity and couldn’t accommodate more students.

Dann Carlson, DOE assistant superintendent of school facilities and support services, told HCDA board members that the school envisioned at 690 Pohukaina would serve about 750 students and help accommodate population growth in Kakaako, where dense high-rise development is growing.

“The DOE’s position is that this is a good fit,” he said. “We see it as kind of a win-win. We are committed to this and committed to trying to make this happen.”

The envisioned school, according to DOE consultant Dean Uchida of the planning firm SSFM International, could become a model for DOE schools near rail stations on Oahu where dense residential neighborhoods may rise.

Carlson said it will cost an estimated $40 million to build the envisioned Kakaako school, of which $6 million was appropriated by the Legislature last year. He said DOE intends to seek the balance from lawmakers.

Under the plan, Forest City would use the state money to build the school for DOE as part of its revised project.

Jon Wallenstrom, president of Forest City’s Hawaii affiliate, said building a school next to high-rise housing is a smart idea that the company has done outside Hawaii. “It’s a great thing to do,” he told the board. “It creates wonderful communities.”

Issues arose over whether substituting a school for civic, commercial and community space that HCDA had requested would be a material change to HCDA’s bid process, and about how the school would be funded.

Carlson said the school would occupy about 100,000 square feet of space and could be viewed as civic space that doesn’t represent a material change in the bid request.

HCDA also originally recommended that 690 Pohukaina contain 800 homes, including 300 affordable units and 500 market-priced units.

Forest City’s original plan called for 390 apartments for tenants earning no more than 120 percent of Honolulu’s median income, 390 units for tenants earning up to 140 percent of the median income and 24 luxury penthouse units.

Wallenstrom said in an interview that the revised plan would have about 400 units, most of which would be at affordable rents, though he declined to share more specifics.

Carlson suggested that HCDA’s board can either decide to proceed with the revised plan, which is what DOE would like, or start over with a new request for proposals that would further delay a project that was previously expected to have been partially opened this year.

HCDA’s board concluded the public portion of its meeting and then met privately to hear advice from lawyers with the attorney general’s office on whether the modified plans conform with the scope of the original proposal request. A decision on whether to move forward with Forest City or solicit new bids for developing the site is expected at a later date.

If the agency opts to pursue the revised plan, it would require that HCDA staff and the developer reach a formal development agreement with financial terms and final plans. Approval from the state Board of Land and Natural Resources also would be necessary because the project site is owned by the Department of Land and Natural Resources.

HCDA recently projected that it could take two years for construction to start on 690 Pohukaina because of the school issue.