What Is An Ohana Unit?
Generically, an Ohana Unit is any second residence on a property, either attached or detached from the main house, where another person or persons may live. This would be similar to what would be called a "Mother-In-Law" Unit on the mainland. However, just because a building or attached dwelling is called an Ohana by a realtor or property owner does not mean it is a legal Ohana dwelling.
It its technical, legal sense, an "Ohana" is a legal second dwelling unit (attached or detached) on a property, where the property is built legally in either in an Ohana-zoned area or in an area where the unit was legal at the time of construction. The purpose of an Ohana (meaning family) Unit is strictly residental use by family members (related by blood, adoption or marriage).
There are many other restrictions on Ohana Units. For example, Ohana Units are not permitted on zero lot line, cluster housing project, agricultural cluster, country cluster, planned development housing, R-3.5 or duplex lots (formally known as two family detached dwelling lots).
There are many pre-existing Ohana Units that are detached second buildings, however, after October 10, 1992, any new Ohana Units built on qualified lots were required to be attached to the main residential dwelling. Owners building these units are required to sign an affadavit that the units will be used only by family members.
It is important to note that Legal Ohana Units are different from a second dwelling which is legal simply due to lot square footage and zoning requirements. In the true Ohana dwelling situation, the lot size will not meet the zoning requirements for a second single-family structure.
Often, Ohana units are detached from the main dwelling and have a second kitchen, and are "grandfathered" in as legal non-conforming structures. There are many restrictions on rebuilding or remodeling existing legal Oahu Units and you should consult with the Honolulu City and County Department of Permitting and Planning and other experts when modifying an existing Ohana Unit.