The city Department of Planning and Permitting supported the 30-year restriction, calling it the “most critical element” of the new rules that extends a home’s affordability for potentially other buyers and aligns with industry practice in hundreds of localities across the country.

DPP, in testimony before the new ordinance was enacted, also said that some places on the mainland have 60-year or permanent restrictions.

“Some people have argued that the extended period will limit a homeowner’s ability to build equity and move up the housing ladder with a large profit after their period of affordability ends,” the agency said in written testimony. “Nevertheless, the public purpose of the (longer restriction) is to help grow and maintain a stable supply of affordable and workforce housing.”

The nonprofit Hawaiʻi Appleseed Center for Law & Economic Justice also backed longer restrictions.

“There are places that require buyback periods up to 100 years,” Gavin Thornton, the organization’s then-co-executive director, said in 2018 as approvals were being debated for Sky Ala Moana. “We need to ensure that we are providing affordable housing for a long time and that it is being built for those that need it most.”