A Honolulu County Councilwoman is urging her colleagues to override Mayor Kirk Caldwell’s veto of a bill to lower by $70 a year the property taxes of homeowners who live in their houses.

Caldwell vetoed the bill on Friday, citing a loss of revenue that could impair the city’s ability to fulfill its financial obligations.

On Tuesday, the Council scheduled a meeting for May 14 to consider overriding the veto. Councilwoman Heidi Ttsuneyoshi, who authored Bill 3, is urging the override. The bill passed the Council 9-0 on April 17. A “supermajority” of six votes is needed to override a veto. The Council has until June 2 to act.

The bill raises the standard home exemption, eligible on properties where the owner is also the occupant, to $100,000 from the current $80,000.

If the homeowner tax class rate stays at $3.50 per $1,000 of assessed value, the homeowner with a house assessed at $880,000 would pay the tax on $780,000 of value, resulting in a tax bill of $2,730 rather than $2,800.

Homeowners who are 65 and older, who now receive higher exemptions, would see a similar break.

Tsuneyoshi said while $70 may not seem like a substantial amount of money, it would represent a change in mindset. The exemption last increased in 2006. And while the rate for owner-occupants has remained at $3.50 per $1,000 of valuation for a number of years, steep rise in sales prices has led to higher assessed values and, as a result, higher property tax bills.

Caldwell, in his memo to the Council vetoing the bill, said the change would cost the city an estimated $10.3 million in property tax revenues “and may impair the city’s ability to fulfill its (employees’ retirement system) and other financial obligations.”

Additionally, “the increased exemptions are broad and do not target residents who would most benefit from a real property tax exemption,” Caldwell wrote.

He urged Council members to re-establish a property tax advisory commission that would look at the entire property tax structure. “The commission may find that the exemption should only apply to seniors on fixed incomes, or that a combination of the real property tax exemption with the existing circuit breaker would most benefit those below certain income levels,” he said.

A property tax circuit breaker, such as the City and County of Honolulu’s Real Property Tax Credit for Homeowners, is a program that provides tax relief such as exemptions or credits targeted at low-income, elderly or disabled property owners.

Tsuneyoshi told the Honolulu Star-Advertiser Tuesday she supports the idea of a tax advisory commission, but doesn’t see it as something that needs to be done before an increased exemption kicks in.

Given that its impact would be minimal, the exemption should be allowed, she said.

Since Caldwell became mayor in 2013, the city revenue base has increased by more than $1 billion, Tsuneyoshi said. “So it’s really not a matter of not having any money, it’s just being able to prioritize our money and understanding that residents deserve to get just a very, very little break on their residential property taxes.”