No historian could pinpoint when the Hawai'i culture of kupuna care was born, but the collective concern for elders as well as the disabled has been enshrined in state law, in various forms, for decades.

For example, 25 years ago Act 54 was signed, assuring that licensed care homes of a limited size would be allowed to operate in residential areas. State law allows counties to restrict other activities through zoning laws, but care-home operations have special protection.

That's why some communities, like Manoa, find themselves in conflict today. State law dictates that the counties must not prohibit any licensed residence for the mentally ill, elderly or disabled — if no more than eight unrelated people live there.

These homes fill a pressing social need. Nearly one-fifth of the population in Hawai'i was 60 years old or older at the time of the 2000 Census, a proportion projected to rise to 26 percent by 2020.

Which means: Many baby-boomers have been worried about the care of their aging parents already, and it won't be long before they will be needing care themselves.

And, unless there's a drastic increase in the number of institutional nursing-home facilities, it's the residential care homes that provide most of the capacity for caregiving.

At the same time, the law and zoning ordinances seem ill-equipped to soften the impact of caregiving in the neighborhood setting.

Some problems can be settled more informally than others. Parking can be an issue, with the occasional stops of supply trucks and the arrival of visiting family members. But in some communities, neighbors have worked out compromises to make the situation livable for everyone.

Other problems are knottier, and require governmental intervention. For example, there's no way to limit the number of smaller care homes in a neighborhood. That allows several care homes to cluster and create the semblance of a larger nursing-home facility.

This must be fixed, with a provision added to the state law enabling the counties to limit the impact of homes operating in close proximity.

Incentives to encourage more smaller-capacity homes that have less potential for disruption to the community should also be explored.

And restrictions on the times trucks could make deliveries could be added to the regulations imposed through the state's licensing process.

For the larger care homes that require a conditional use permit, adequate consideration must be given to the needs of the community for a restful home environment.

Additionally, the state needs to support programs that enable "aging in place" so that elders can remain in their own homes for as long as possible, with additional community-based support.

In Hawai'i neighborhoods — especially within the Honolulu urban core — population density compounds the challenge of balancing everyone's needs.

But all of Hawai'i's people deserve the option of living within a residential setting, regardless of age or infirmity. State and local government must find ways to preserve that option without causing needless tension among neighbors.