The future of Vashon High School — from the condition of its classrooms to the quality of its athletic facilities — will soon be in the hands of Vashon voters.

After a process that by some accounts took four years, the Vashon Island school board decided Thursday night to put a $75.5 million bond proposal before voters, a measure that, if approved, would lead to a far-reaching overhaul of the high school’s aging facilities.

In a 4 to 0 vote, with one member abstaining, the board decided to go with what’s been called the full package — a proposal that includes the construction of a new 40,000-square-foot classroom building and a second gym, as well as improvements to the track, the field, the grandstand, several existing buildings and other infrastructure.

The school district will hold a special election on the bond measure on March 10.

At the school board’s meeting at McMurray Middle School Thursday, the five-member board — which has moved forward on the decision incrementally and with considerable public input — listened to several Islanders weigh in on the proposal before taking its final vote.

It was a crowd particularly sympathetic to the condition of the school. Many, from teachers to coaches to parents, stood before a podium and told the board they supported the full package rather than alternatives that had been floated in an effort to trim costs.

“I fully support the bond measure,” parent Charlie Pieterick told the board. “It addresses the whole child. It addresses the whole school. It addresses the whole community.”

Harriet Van Buren, a senior citizen, said she knew the board had heard from some retirees in the community that “my age bracket won’t support it. And that’s simply not true.”

Brian Brenno, a glass-blower on Vashon, described himself as the kind of person who might oppose the measure. “I’m totally cash poor and land rich. I don’t have a 401(k). And I’m totally for it. There’s a need here. … It’s time. Overdue,” he said to applause.

The school board’s near-unanimous vote came after a meeting two weeks ago when the five members appeared deadlocked over the size of the final measure. Ironically, that deadlock was cleared by a development stemming from the region’s faltering economy: Because of falling prices and a more competitive bidding climate, the company that estimates costs reworked its analysis and determined that the project costs would escalate over time by 4 percent rather than 6 percent, school board members reported.

That brought the price for the full package down from $79.45 million to $75.5 million — a number that was more acceptable to the two board members, Kathy Jones and Laura Wishik, who had sought ways to trim costs.

But even with a newly priced proposal before them, Wishik told the crowd she remained concerned about a $75.5 million proposal and would vote for it “reluctantly.”

“I love this community. And I love the diversity of this community. I love that we have people here who try to live simply. … There’s a limit to how much we can tax this community. And this eats a big chunk out of that pie,” she said.

Dan Chasan — the one member who abstained — also expressed concern over the costs. “I still think athletic improvements should have been separated out,” he said.

But other board members made passionate speeches in favor of the proposal, with board chair Bob Hennessey calling the measure “the long-term solution we’ve been talking about for four years.”

Noting that Vashon kids shouldn’t necessarily have the best schools in the region, nor, he said, should they have the worst — which they do now, he contended.

The school board can’t know for sure if voters will approve the measure in March, he added, but it shouldn’t shy away from providing leadership on what he termed a critical issue.

“I believe I could convince most people on this Island … that this is good value for their dollar,” he said. “These are taxes for Vashon kids, … and they’re the best tax dollars you’ll ever spend.”

After the board’s vote, the crowd in the multi-purpose room at McMurray Middle School stood up and applauded.

“I am thrilled,” said Vashon High School principal Susan Hanson. “I am proud of our school board. I am proud of the staff. I am proud of the community. … I can hardly wait to open the new front door.”

With less than three months before the vote, supporters of the measure said they’re now ready to launch a full-throttle campaign. A campaign committee chaired by Nancy Kappelman has been formed, with an $8,000 budget, a Web site under construction and placards about to be printed.

“Yes, it’s worth it. Vashon for schools,” the black, red and white signs will read.

Jean Bosch, a real estate agent active in several civic circles on the Island, will manage the campaign. She said the campaign will attempt a variety of approaches to garner support for the measure — including dozens of tours of the high school and in-depth, informational e-mails to what she called “25 key communicators.” Those communicators, in turn, will forward the messages to friends and colleagues, creating a kind of viral e-mail campaign in support of the measure, she said.

So far, she said, the tours have been particularly powerful in conveying the message she and others are trying to communicate.

“If we can get enough people into the tours, it’ll pass handily,” she predicted. “If people see the sorry state of the high school, we’ll have a successful campaign.”

If passed, the measure will cost homeowners $1.91 per $1,000 of assessed value — or $764 a year for a home assessed at $400,000. Supporters, however, say it’s important to think of it not in terms of the bond’s absolute costs but in terms of what property owners historically have paid to support the schools.

According to charts produced by the school district, property owners paid on average $1.58 per $1,000 in assessed value over the past 12 years to retire a bond that was used to build Chautauqua Elementary School. That means property taxes will only go up a bit if the new bond measure passes, supporters say; for a house valued at $400,000, the increase would be $132 a year in property taxes.

But Bosch notes that the issue of just how much a homeowner will pay is “a squishy situation”; Islanders’ tax bills will vary, she said, depending on their tax bracket, the value of their home and where the district is in the life of the 20-year bond.

“It’s a moving target,” she said, adding, “That will be the campaign’s biggest challenge — arriving at a shared understanding of the tax implications.”