LIHU'E, Kaua'i — Owners of small agricultural and open-zoned parcels on Kaua'i who expected someday to build second homes are facing an end-of-the-year deadline when they must put in additional dwelling units or they may lose the opportunity.

Jeff Goodman, who is trying to preserve the right to build two homes on a piece of property he bought years ago for his two sons, worries about not getting the job done in time.

"I've been very diligent. What free time I have, I've spent on this project, and I feel like it's escaping me," Goodman said.

There may be several hundred Kaua'i property owners in similar situations.

"There are people who have been sold properties that are reliant on that ADU (additional dwelling unit), and they may lose their right to build a home," said Rick Shaw, president of the Kaua'i Board of Realtors.

Some members of the County Council appear ready to let that happen.

"We're having a lot of problems with infrastructure right now. I think people have had ample notice when this is going to be ending," said council member Shaylene Iseri-Carvalho.

Kaua'i Planning Department staffer Myles Hironaka said that about 400 agricultural and open lots have received zoning permits for ADUs since 1989. Shaw said there may be another 500 to 700 parcels that could qualify for them.

"Those are astronomical figures," Iseri-Carvalho said.

In the late 1980s, the County Council allowed owners of non-residential parcels to build a second home. It was during the period when residential-zoned parcels under certain circumstances were allowed a second unit. These were marketed as additional space for family members and called " 'ohana units."

The additional dwelling units on residential lands statewide are permitted in perpetuity, but the Kaua'i ordinance that allows them on nonresidential land expires Dec. 31.

The County Council has proposed a 10-year extension of the measure, but it may not have strong support. The issue is before the Kaua'i Planning Commission, which has a public hearing scheduled on the issue July 11, after which it makes its recommendation to the council.

Among those parcels where additional units have not been built, in some cases, residents have held on to small agricultural or open-zoned parcels, expecting to build the second home when children are in need of the housing; or planning to divide off building lots for the ADUs through a condominium process, said Mike Dyer, of Kilauea Real Estate Co.

In other cases, those separate lots may already have been sold, and if people have not built, they now face the possibility of owning property on which no home can be placed — and suffering a drop in real property value.

"Realtors may not have been fully informing people," Iseri-Carvalho said.

Shaw said that it is possible that the deadlines of the ADU process were not fully discussed to buyers when those deadlines were years away, or that property owners have not kept track of the timing.

That's one reason the Board of Realtors — which has not taken a stand either for or against the reauthorization of the ag-open ADU bill — is supporting a wide public discussion.

"Excellent cases can be made for both sides of this subject," Shaw said.

But owners of possible ADU properties who have not gotten their permits or started building are at some risk — it may not be until September or later that the council votes on an extension. And if it rejects an extension at that time, there may not be time for residents to obtain a permit before the end of the year.

"I think the way it's happening is a negative thing for Kaua'i," said real estate salesman Matt Beall. "They're creating a huge rush, and the county permitting offices are already understaffed for their workload."

Kilauea resident Goodman said he bought a property that qualified for a home and an ADU, so that each of his sons could have a place for a home. He hadn't intended to build himself, but is now finding that he may have to, just to preserve the right to have two homes there.

"I've had to spend a lot of money on attorneys, architects, surveyors. It's a significant amount of money. I'm finding myself in a position that if I don't do something, I won't have it available at all," he said.

There is also the question of what a landowner needs to do to protect the right to an ADU unit: Is a zoning permit enough, is a building permit enough, must construction have started, or must it be completed?

"There seems to be no clear administrative rules to outline the process which will determine whether or not a landowner has 'vested' a right to build an ADU on a qualified lot," the Board of Realtors wrote in a letter to the council. It recommends that the council immediately give the public some indication of its preferences. The Realtors' own preference is an extension of five to 10 years, with some restrictions.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.