ADU Rules in Honolulu, HI — 2026 Guide
Check if your Honolulu property qualifies for an ADU in 20 seconds
Honolulu ADU Rules at a Glance
Honolulu is considered ADU-friendly. Here are the key regulations.
- Honolulu allows ADUs up to 800 sqft on residential lots of 3,500+ sqft.
- No parking requirement for ADUs on lots near transit stations.
- Owner-occupancy required on the primary dwelling.
- High construction costs ($300–$500/sqft) make feasibility analysis critical.
What ReadyPermit Checks for Honolulu Properties
Enter any Honolulu address and get an instant ADU feasibility analysis covering:
Zoning Compliance
Verify your Honolulu lot is zoned for ADU construction under current HI and local rules.
Setbacks & Coverage
Check required setbacks, lot coverage limits, and height restrictions for your specific parcel.
ADU Size Limits
Calculate the maximum ADU square footage allowed based on your lot size and primary dwelling.
Permit Requirements
Understand what permits and approvals Honolulu requires before you can break ground.
Flood & Hazard Zones
Identify if your property falls in a flood zone, fire zone, or other hazard overlay.
Lot & Parcel Data
Pull parcel boundaries, lot dimensions, and existing structures from county records.
Check Your Honolulu Property Free
Enter your address below. In under 20 seconds you will know if your Honolulu lot qualifies for an ADU — no phone calls, no waiting.
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