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East Honolulu, HI Accessory Structures: ADU Rules (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

ADU rules in East Honolulu, HI, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Code Section
ROH 21-5.720 (Ord. 15-41)
Jurisdiction
City and County of Honolulu (LUO, ROH Ch. 21)
Permitted districts
Residential (R-3.5 to R-20) and Country
Minimum lot size
3,500 sq ft
Max ADU size
400 sq ft (lots 3,500-4,999); 800 sq ft (lots 5,000+)
Number allowed
1 ADU per lot
Parking
1 extra off-street space; waived within 1/2 mile of rail station
Infrastructure
Written agency confirmation of water, sewer, roadway capacity required
Covenant
Recorded with Bureau of Conveyances / Land Court; long-term rental only

Summary

East Honolulu (City and County of Honolulu) permits one accessory dwelling unit on residential and country lots of 3,500 square feet or more under the Land Use Ordinance, capping the ADU at 400 square feet on lots up to 4,999 square feet and 800 square feet on lots of 5,000 square feet or more, with one extra off-street parking space and a recorded covenant.

Covenant for Accessory Dwelling Units: The owner or owners of the lot must record covenants running with the land with the Bureau of Conveyances or the Land Court of the State of Hawaii, or both, as is appropriate. The covenant must be recorded on a form approved by or provided by the Director and may contain such terms as the Director deems necessary to ensure its enforceability. The failure of an owner or of an owner's heir, successor or assign to abide by such covenant will be deemed a violation of Chapter 21 and will be grounds for enforcement by the Director pursuant to Section 21-2.150. The covenant must state: ... "Neither the owner or owners, nor the heirs, successors or assigns of the owner or owners will submit the lot or any portion thereof to a condominium property regime under the provisions of the HRS to separate the ownership of an accessory dwelling unit from the ownership of its principal dwelling unit."

Source: Revised Ordinances of HonoluluView official code

Full Breakdown

East Honolulu has no separate city government; it is part of the City and County of Honolulu, whose Land Use Ordinance (LUO), Revised Ordinances of Honolulu (ROH) Chapter 21, governs accessory dwelling units (ADUs) island-wide on Oahu. 5, R-10, R-20) and country zoning districts. An ADU is a second dwelling unit with its own kitchen, bedroom, and bathroom, attached to or detached from the principal dwelling. An ADU is allowed only on a zoning lot of 3,500 square feet or more with a single existing or proposed principal dwelling unit, subject to adequate infrastructure and all other LUO requirements, and only one ADU is allowed per lot.

The maximum floor area is 400 square feet on lots from 3,500 to 4,999 square feet, and 800 square feet on lots of 5,000 square feet or more. One additional off-street parking space must be provided for the ADU on top of the parking required for the principal dwelling, except for ADUs within one-half mile of a rail transit station, and the ADU space may be a compact stall. Before a building permit issues, the applicant must obtain written confirmation from the responsible agencies that wastewater treatment and disposal, water supply, and access roadways are adequate.

The owner must record a covenant running with the land with the State Bureau of Conveyances or Land Court (or both) on a form approved by the Director; the covenant bars renting the ADU for less than long-term use and bars separating ADU ownership from the principal dwelling under a condominium property regime. The comprehensive LUO rewrite adopted as Ordinance 25-2 (in effect September 30, 2025) raises the small-lot maximum to 500 square feet and carries forward the single-ADU, infrastructure, and covenant requirements.

Violations & Fines

An ADU built or used in violation of Chapter 21, including failure of the owner or the owner's heir, successor, or assign to abide by the recorded covenant, is a violation of the Land Use Ordinance and is grounds for enforcement by the Director of the Department of Planning and Permitting under ROH Section 21-2.150, which authorizes notices of violation, orders to correct, and civil fines for continued noncompliance.

Frequently Asked Questions

Does East Honolulu have its own ADU ordinance?
No. East Honolulu is part of the City and County of Honolulu and has no separate city code. ADUs are governed island-wide by the Land Use Ordinance, Revised Ordinances of Honolulu Chapter 21, Section 21-5.720, added by Ordinance 15-41 in 2015.
How large can an ADU be in East Honolulu?
Under ROH Section 21-5.720, an ADU is limited to 400 square feet on lots between 3,500 and 4,999 square feet, and 800 square feet on lots of 5,000 square feet or more. Only one ADU is allowed per zoning lot. The 2025 LUO update raises the small-lot cap to 500 square feet.
What lot size do I need for an ADU in East Honolulu?
The lot must be at least 3,500 square feet and zoned residential or country, with adequate infrastructure. Before a building permit issues, you must obtain written confirmation from the responsible agencies that wastewater, water supply, and access roadways can accommodate the ADU.
Do I have to record anything to build an ADU?
Yes. The owner must record a covenant running with the land with the State Bureau of Conveyances or the Land Court of Hawaii on a form approved by the Director. The covenant requires the ADU to be used only for long-term rental and bars separating ownership of the ADU from the principal dwelling under a condominium property regime.

Sources & Official References

Other rules in East Honolulu

All East Honolulu rules

How East Honolulu compares: Easiest Cities to Build an ADU·Compare East Honolulu to another location·View the Hawaii accessory structures overview

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