The Atherton Family Foundation has sold the land under a Kakaako affordable-housing rental tower to a state agency as part of a deal to improve the property through a private-public partnership.

The Hawaii Housing Finance and Development Corp., a state agency, said it paid $17.6 million for the leased-fee interest under Kamakee Vista, a building with 226 apartments that the agency built in 1991.

HHFDC had a land lease with the local nonprofit foundation that ran through 2056 but wanted to include the property in a portfolio of six affordable-housing complexes sold to Komohale LP, a partnership between local developer Stanford Carr Development LLC and Los Angeles-based Standard Communities, under 75-year land leases.

Carr and Standard, which lease the state land for $1 a year, paid $130 million for the portfolio earlier this year and are required to renovate the properties within three years at a cost of $85 million and may raise rents only modestly while keeping rates within state limits for affordable housing.

HHFDC sought competitive bids for the deal with the intention of having the portfolio renovated faster, more efficiently and at no cost to taxpayers.