Honolulu Committee Advances Citywide ADU Expansion Ordinance

Honolulu Committee Advances Citywide ADU Expansion Ordinance

In early February 2026, the Honolulu Land Use and Transportation Committee advanced an ordinance to expand accessory dwelling unit (ADU) construction citywide. The measure, which now moves to the full City Council for consideration, includes amendments addressing unit-size minimums and expanded zoning flexibility.

What the Ordinance Proposes

The key amendments in the advancing ordinance include:

• Expanded zoning eligibility — ADUs would be allowed alongside single-family homes in Residential (RS), Duplex (RD), and Residential Mixed-Use zones
• Detached and attached ADUs — Both configurations would be permitted, giving homeowners more design flexibility
• Updated size standards — Amendments address minimum unit sizes to ensure livable, functional spaces
• Broader geographic reach — The ordinance aims to make ADU construction available across more of Honolulu, not just select neighborhoods

Context: Why This Matters

Honolulu's existing ADU program has produced approximately 1,320 units since its inception — far below the targets needed to meaningfully address the housing shortage. The state needs an estimated 64,000 additional housing units, and ADUs are widely seen as one of the fastest, most cost-effective ways to add supply without large-scale development.

The barriers have been well-documented: restrictive zoning, complex permitting processes, high construction costs, and until recently, limited financing options. This ordinance directly addresses the zoning barrier by opening more areas to ADU construction.

Combined with Fannie Mae Changes

The timing is notable. With Fannie Mae expanding ADU financing rules effective March 31, 2026, homeowners will soon have both the zoning permission and the financing pathways to build ADUs more easily. The combination of local zoning reform and federal financing changes could accelerate ADU construction significantly.

What Homeowners Should Consider

If you own property in Honolulu and have been considering an ADU, the regulatory environment is moving in your favor:

1. Check your zoning — The expanded ordinance may newly qualify your property for ADU construction
2. Understand the economics — Rental income from ADUs in Honolulu can range from $1,500 to $3,000+ per month depending on size and location
3. Plan ahead — Even with streamlined permitting, ADU projects require careful planning around design, construction, and property management
4. Analyze the investment — Factor in construction costs ($200–$400 per sq ft in Hawai'i), financing terms, and projected rental income to understand your return

The Bigger Picture

ADU expansion represents a shift in how Honolulu approaches housing supply. Rather than relying solely on large-scale developments, the city is empowering individual homeowners to become part of the solution. For homeowners with the right property and financial position, this creates a genuine wealth-building opportunity.

The ordinance still needs full Council approval, so the final details may evolve. We'll continue tracking this legislation and reporting on developments as they happen.

Sources: Honolulu Land Use and Transportation Committee proceedings (February 2026); Hawai'i Living News; Building Industry Association of Hawai'i.