OURchitecture

Jun 27, 2010

Where can we fit ADU's in Honolulu?

Other states that have adopted Accessory Dwelling Units (ADU's) require adequate utility infrastructure to support the added dwellings.

In Honolulu, similar requirements have already been studied and mapped for Ohana dwelling units. The Dept of Planning & Permitting established Ohana Zones. To determine if a property is Ohana Eligible, go to the City's GIS website and enter the property address or tax map key number.

For the island of Oahu, which encompasses the entire City & County of Honolulu, the Ohana Zones are hatched green lines.
The Ohana Zones were established several years ago and may not have updated since. For example, in portions of lower Manoa, the Sewer Capacity has been exhausted and there is no additional capacity for new Ohana units. But the City has not yet updated the Ohana Zone to exclude this area.

You can see that the Ohana Zones follow the underlying zoning of the land. For example, Commercial, Institutional and High Density Residential zoned areas are excluded from the Ohana Zone. A large portion of the lower density residential zones colored yellow are also included in the Ohana Zone (green hatched area) however, due to lack of sewer, water or road widths, not all of lower density residential areas were deemed suitable for Ohana Units, and were thus excluded from the Ohana Zone.

Based on the Honolulu Dept of Planning and Permitting, there are an estimated 17,098 Ohana Eligible properties and approx 2,000 existing Ohana units. Therefore an estimated 15,098 units are readily identifiable properties that could potentially accommodate an ADU unit.