Hundreds of people who own affordable high-rise homes in Kakaako could soon have an opportunity to help produce new affordable housing for local residents.

A state agency that regulates development in the area is proposing a novel idea aimed at pumping up a near-empty fund that primarily has been used to build low-income rental housing in Kakaako in past decades. The plan has the potential to generate up to $90 million initially, and perhaps close to $200 million within just a few years after that.

However, far less could actually result, given the dynamics of what’s being proposed.

The Hawaii Community Development Authority recently suggested to its board that the agency’s rules be amended to allow owners of certain condominiums in Kakaako to prepay an obligation they have to repay a portion of what essentially was a discount on the homes they bought at below-market prices that was subsidized by developers of market-priced housing in the area.

This debt, known as shared equity, isn’t due until the original buyers of a subsidized condo sell their home.

HCDA wants to give these owners an option to pay back the shared-equity debt before any future resale.

The agency’s total value of existing shared equity is roughly $90 million. And because many more new subsidized affordable condos are slated to be produced over the next few years, the value of shared equity is expected to jump to at least $170 million and perhaps closer to $200 million.

For example, 150 affordable condo units in the nearly finished ‘A‘ali‘i tower at Ward Village will contain about $20 million in shared equity for HCDA, or about $130,000 per unit.

Ward Village developer Howard Hughes Corp. also is seeking to build a 697-unit affordable tower called Ulana Ward Village that would provide roughly $50 million in shared equity for the agency, or about $72,000 per unit.

Another major Kakaako landowner, Kamehameha Schools, plans to produce a few additional condo towers that are expected to trigger requirements to provide below-­market units with shared-equity obligations.

Under HCDA rules, developers of high-density projects in Kakaako must make 20% of residential units affordable to households with below-moderate to high- moderate incomes. Shared equity also applies to homes built under a relatively new HCDA workforce housing rule in which two towers at 801 South St. were built several years ago.

HCDA essentially wants to tap into the stored value of all this existing and coming shared-equity debt.

“We could do a lot of (affordable) housing projects,” Deepak Neupane, HCDA executive director, said in an interview.

Historically, the agency has received a trickle of shared equity from resales of affordable condos that mainly began to rise during a real estate boom in the 1980s and have continued since.

HCDA puts shared-equity payments, along with fees that some developers pay in lieu of producing below-­market housing, into a special fund the agency uses to finance affordable-housing projects.

This fund has helped produce projects that include the 243-unit Honua­kaha condo and rental apartment complex at 545 Queen St., the 75-unit Na Lei Hulu Kupuna apartment building at 610 Cooke St. and a few others.

The last project funded in part by shared-equity payments was Halekauwila Place, a 204-unit rental tower for low-income households. A private developer built the project on state land in 2014 and received a $17 million HCDA loan.

Today, there is only about $4.5 million in HCDA’s affordable-­housing fund.

Yet a big question exists as to how many homeowners who owe shared equity to HCDA would opt to pay it before selling their home.

Neupane told the agency’s board at a meeting earlier this month that he expects 25% will pay early.

The agency’s proposed rule change would allow owners of subsidized condos to prepay as little as 25% of the entire obligation as a way to make it easier for more buyers to contribute. Prepayment would not be a requirement.

Neupane figures that many homeowners will want to prepay the debt simply to be rid of the obligation.

Prepaying also could represent a form of public serv­ice for homeowners helping others, especially those with lower incomes, obtain affordable housing.

One disincentive, however, is that waiting to pay back shared equity until required likely will be less costly to homeowners because the value of a dollar decreases with inflation.

HCDA calculates shared equity as the lesser of a fixed amount based on the initial condo sale price or a formula tied to a future resale price. Neupane said that over the last 30 years, the initial fixed amount has always been less, even though home prices have appreciated dramatically during this time.

The agency’s board anticipates making a decision on whether to approve the rule change and plan at its meeting Wednesday.