Benson High School, pictured in 2010, is on the list of future PPS reconstruction projects.

Portland Public Schools officials are crunching numbers to figure out how much PPS property owners will have to pay to rebuild three additional high schools, and the initial estimate could add hundreds of dollars to voters' annual tax bills come November 2016.

Didn't PPS just pass a $482 million construction bond, you ask? Yes, it did—in November 2012. But PPS officials are considering asking voters to approve a second bond before the 2012 bond sunsets. The 2012 bond charges homeowners $1.10 per $1,000 in assessed value for eight years.

C.J. Sylvester, who is set to leave soon as PPS's chief of school modernization, told a committee of school board members last week that the new measure could bring the cost of the district's bonding closer to $3 per $1,000 in assessed value than $2 while both bonds are in place. Under state law, there's no cap on the amount of money voters can approve for capital projects.

For a homeowner with a house assessed at $150,000, that could bring the cost of PPS's reconstruction from $165 to nearly $450 per year for four years.

Jon Isaacs, a spokesman for PPS, says it's too early to say for sure what the dollar amount might be. PPS plans to poll residents on the topic, but hasn't done so, he says.

And PPS board members have asked Sylvester to give them a more detailed analysis of the estimated cost of rebuilding Lincoln, Madison and Benson high schools—the next round of schools slated for modernization.

Corrections: An earlier version of this story said Sylvester gave a specific dollar figure. She did not, she says. It also said she was retiring. She is leaving the district, not retiring.