A conflict between Honolulu Waldorf School and Niu Valley residents opposed to its expansion plans has escalated, with the school now suing some of its neighbors.

Waldorf filed a lawsuit late last month against the city Zoning Board of Appeals and 20 nearby residents who have appealed the city's approval of the school's plan. The lawsuit is asking, among other things, that the Circuit Court declare that under the board's rules, the residents' appeal to the board should have been denied.

The residents were shocked to learn they were named in the suit, and they and other neighbors are ready to fight back, said their attorney, Eric Seitz. He said residents plan to protest at Waldorf's fair this weekend. Both sides also have scheduled news conferences today.

"As far as we're concerned, now we're going to make it very clear to them we don't even want them in our community any longer," said Seitz, who also is president of the Niu Valley Community Association. "They no longer are going to have freedom to exist in our valley to do what they want to do. They're going to be under siege."

Waldorf school administrative director Connie Starzynski said the lawsuit was a last resort that followed attempts to work with residents, including an unsuccessful offer to seek a resolution through mediation.

Starzynski said construction must begin soon so Waldorf can move its high school, now in Kahala, to the Niu Valley K-8 campus. The school's Kahala lease is to expire in 2011, and the school may have to vacate at the end of 2010, she said.

"We've been really paralyzed from moving ahead with our plans," Starzynski said. "We have diligently gone through all of the necessary steps to address the concerns of our neighbors so that our high school can be smoothly integrated into the neighborhood."

The city Department of Planning and Permitting in January approved Waldorf's request for a conditional use permit to build a two-story, 10,000-square-foot high school building on its Niu Valley campus. The city also imposed traffic, noise level and other conditions on the school, which Starzynski said Waldorf intends to comply with.

But Seitz said a number of residents felt the restrictions didn't go far enough and were concerned that the school would not abide by them. Twenty-one residents petitioned the Zoning Board of Appeals in February.

The matter has been delayed, however, because three of the five members of the appeals board voluntarily recused themselves from the issue during meetings, leaving the board with no quorum to hear the case.

Waldorf said the Niu Valley residents' appeal should have automatically been denied, citing a Zoning Board of Appeals rule that states: "Failure to obtain a majority vote at two separate meetings shall constitute a denial of appeal."

But Seitz said the rule doesn't apply to the situation, in part because the board hasn't reached a quorum. The rule is intended to prevent the board from delaying action when it has the capacity to act, which is different from what's happening with the Waldorf case, he said.

Wil Yamamoto, one of Waldorf's attorneys, said the city is evaluating amending an ordinance to address such quorum issues, but that he was told that would take at least three months. Without a resolution, the school said, it had no choice but to sue.

Niu Valley resident Martin Plotnick, among those named in the lawsuit, said he considers the lawsuit "a form of intimidation."

"We're not a bunch of raving petitioners," Plotnick said. "We're just saying to start living with us, being a good neighbor. And the bottom line is the filing of that suit was clearly not an act of a good neighbor because it did infringe upon our constitutional rights. ... You can't take my due process away from me."

Yamamoto said the lawsuit wasn't intended to intimidate residents. He said the residents were named in the suit so that a Circuit Court decision would be binding on them.

"All we're looking for is the Circuit Court to make a decision on the interpretation of the (board's) rule," he said.

The private school, which has been at 350 Ulua St. for more than 40 years, has 240 students enrolled in preschool through eighth grade. Starzynski said the new high school will have up to 100 students.

"This was not our preference," Starzynski said of the suit. "This is really not a happy time. Our teachers are not happy. Our parents are not happy. We just would really like to resolve this issue."

Reach Lynda Arakawa at larakawa@honoluluadvertiser.com.