The Hawaii Community Development Authority has a golden opportunity to achieve dual goals with its newest project: add affordable rental apartments to Kakaako and demon- strate to private landowners that even small urban parcels can be suitable for "micro unit" buildings that generate reliable income for landlords.

The HCDA last week issued a request for proposals for just such a housing project on a 10,409-square-foot site it owns at 630 Cooke St. in Kakaako Mauka, land currently occupied by a parking lot and a community garden for residents of a nearby senior-citizen community.

The agency seeks a development partner for the planning, design, construction, financing and operation of the residential project.

HCDA envisions a mid-rise building that would include at least 50 studio and one-bedroom units that are no bigger than 300 square feet each and rent for about $1,000 a month.

That’s small, but livable for the single people and couples who comprise a sizeable share of Oahu’s population.

Simple efficiency apartments of this size are not unusual in cities like Seattle and Portland, or even in Hawaii’s tourist districts, such as Waikiki.

Building them in Kakaako makes sense, because what renters lose in square footage they would make up in affordability (smaller is cheaper, after all) and in location, a prime spot in town that ends the maddening suburban commute to work and, with the advent of rail transit, might even eliminate the need to own a car.

In fact, the HCDA’s RFP gives special considerations to bids that reduce the number of parking stalls needed by incorporating the concept of car-sharing into the plan.

This is the future of Oahu: dense, urban living that capitalizes on transit-oriented development along the coming elevated rail-transit route. That this housing proposal, limited in size and scope as it is, caters to renters in the low- to moderate-income group is a relief amid the continuing wave of high-rise luxury development in Kakaako. Those super-luxe buildings are attainable by only Oahu’s wealthiest residents, and by the seemingly endless stream of super-rich investors from offshore.

Micro units like those sought for 630 Cooke St., meanwhile, could appeal to any number of local tenants, including retirees seeking to downsize from larger homes to "age in place" in more manageable dwellings; recent college graduates and young couples who have jobs but don’t earn enough to pay Honolulu’s market rates, so are bunking still with mom and dad; and needy people on the brink of homelessness or already suffering that fate. Development plans that emphasize "supportive housing," which meets the special needs of elderly or disabled residents, also will get special consideration.

At this site, HCDA would retain title to the land, and the development partner would be responsible for managing the property once it is built. Since this is a government project aiming to a certain economic group, income limitations on tenants will apply.

Fifty affordable rentals is nothing to sneeze at, especially in urban Honolulu. Beyond adding to the much-needed supply of affordable housing, though, we hope this HCDA project succeeds because it could inspire others near the rail-transit route. Private landowners who previously considered their individual lots too small for an apartment building might realize that a midrise full of micro units fits just fine. Affordable rentals that meet the tenants’ needs as well as the landlords’ would be a win-win for Honolulu.