Honolulu officials are considering ways to boost city income and expand the pool of rental housing by raising the property taxes on homes that have been left vacant by their owners.

There are 34,253 empty housing units in Honolulu County, or about a 10th of the total housing stock, according to the 2020 U.S. Census.

City officials are preparing a request for proposals for a study that would examine why so many houses are vacant, whether and how to implement a special tax on them and and how much it would cost officials to enforce it.

“A lot of cities, from San Francisco to Buffalo, are looking at different variations of vacancy taxes,” said Anthony Flint, a senior fellow at the Lincoln Institute of Land Policy. The idea, he said, is to encourage property owners to keep homes and vacant developable land in active use.

Similar efforts elsewhere have had mixed results.

Even advocates of the concept, including Will Caron of the Hawaiʻi Appleseed Center for Law & Economic Justice, say that any such measure here would need to be “carefully calibrated” to be effective at boosting housing stock, and also fair and equitable to owners.