(BIVN) – A new bill was signed into law this week, allowing Hawaiʻi island homeowners to build up to three accessory dwelling units, or ADUs, on their properties.

Mayor Mitch Roth signed County Council Bill 123 on Tuesday, “helping address the county’s housing shortage and enabling local families to stay in Hawai‘i”, a news release announced.

The bill was co-drafted by Council Chair Heather Kimball, Councilwoman Ashley Kierkiewicz, Planning Director Zendo Kern, and Deputy Director Jeff Darrow.

“Hawaiʻi County is leading the way with Bill 123. ADUs offer a flexible and affordable housing solution for our residents,” said Council Chair Heather Kimball. “Building ADUs for parents, children or long-term renters can help families stay together here on the island and can help homeowners generate extra income needed to get by. By encouraging development of existing properties in urban areas close to school, work, and commercial areas, ADUs also promote more sustainable land use practices outside the urban core.”

The bill will replace previous restrictions on ʻohana dwelling units, and provide more flexibility for homeowners to add ADUs, which will have a size limit of 1,250 square feet. The new law is said to part of a County effort to tackle the housing crisis “while promoting long-term stability and sustainability.”

“Bill 123 is a significant step toward expanding housing opportunities on Hawaiʻi Island,” said Councilmember Ashley Kierkiewicz. “By allowing more ADUs in urban areas, we’re encouraging smart growth within our communities. This practical solution not only increases housing availability, but also empowers residents to actively contribute to addressing our island’s housing shortage.”

Key amendments include:

• Allowing ADUs, whether detached or attached, to be built alongside single-family homes in Residential (RS), Duplex (RD), Residential-Agricultural District (RA), Agricultural (A), and Family Agricultural (FA) districts.
• Limiting each property to a maximum of three ADUs.
• Ensuring compliance with infrastructure and safety standards, including requirements for sewage disposal and water supply.
• Restricting the use of ADUs for transient accommodations, with limited exceptions.

“The ability to build additional dwellings on existing properties is essential in addressing our housing shortage, but it’s also about preserving our communities and ensuring that future generations — our keiki — can continue to live and thrive here in Hawai‘i,” said Mayor Mitch Roth. “This bill expands our housing inventory in a way that is both sustainable and community-centered.”