Between the rise in the number of condo conversions and the increase in expiring HUD contracts on affordable units, the state faces a growing deficit in affordable housing stock that it can't ignore.

That gives the state a narrow window to find solutions to address the shortage through policies that preserve existing affordable stock, encourage public-private partnerships and reflect sensible planning. Anything short of that could result in a flood of displaced renters.

According to The Hawai'i Real Estate Commission, 5,000 affordable rental units were converted to condos in the past three years, a sharp increase from the previous decade. And with costs for new construction skyrocketing, developers turning to conversions is a trend that's likely to continue.

At the same time, affordable units, guaranteed by HUD loans, are expiring. More than 1,900 affordable units could be lost statewide by 2016.

Linda Smith, Gov. Linda Lingle's senior policy adviser, said the state is focused on supply, and rightly so. Lingle has proposed adding $50 million to the Rental Housing Trust Fund over the next two years. But the Legislature must permanently fund the Rental Housing Trust Fund at 65 percent of the conveyance tax to assure the state can meet demand.

The state estimates a need for 17,000 affordable rental units. Dan Davidson, executive director of the Hawai'i Housing Finance and Development Corp., says with current resources the state can expect to add 300 affordable rental units each year; a new HHFDC plan seeks to add 3,500 units over five years.

That's a start. But preventing any loss of affordable housing is critical. The state must do more than tread water.