Last week the Vashon School Board’s five members showed sustainability was a priority for the new Vashon High School when they approved several green additions for the $47.7 million project.

At the Thursday board meeting, Eric Gill, the school district’s capital projects manager, explained that the current high school design — completed under budget — is very energy efficient, exceeding the state’s strict energy codes by more than 20 percent.

“Just meeting energy code is pretty good, so beating it by … 20 percent, we’re doing pretty good. I’m really pleased that our baseline is there,” Gill said in an interview.

With that in mind, the school board approved four time-sensitive additions to the high school design — two meant to improve energy efficiency and two for water conservation. In the coming months, the board will consider several other green improvements, deciding how to spend state funds, grant money and savings achieved in construction.

Most significant last week was the board’s 4-1 approval of an air-to-water heat pump, a more efficient heating and cooling system that will replace a traditional gas boiler in the building plans. Board member Steve Ellison voted against the system, saying he thought the money could be better spent in other ways.

Board members noted that the $250,000 system won’t save the district much in energy bills — about $4,500 a year — but will free the building from using fossil fuels and will have large implications for the high school’s future.

With a heat pump, unlike with a boiler, the building could eventually go “off the grid,” or be powered entirely by solar energy. Though solar panels aren’t currently included in the building’s design, Gill said they could easily be installed at a later time.

“It’s energy efficiency that isn’t going to save us a lot of dollars,” board member Laura Wishik said of the heat pump in an interview. “It’s more of a philosophy that we really want to have that potential.”

Wishik said she believes solar panels will become more affordable in the future, and a community group may even fund their installation at the high school.

“I left that meeting thinking, ‘Golly, we’re all really hopeful people,’” she said.

The board also approved $45,000 in additional insulation for the building, which is estimated to save the district about $900 a year in energy costs. Should the board eventually choose to add triple-pane windows and a daylight harvesting system as well, the design team estimates the district would save about $14,000 a year in energy costs and the building would exceed state energy code by more than 40 percent.

At the meeting the board also approved two water-saving alternatives to be written into the building’s plans. They unanimously went for an $18,000 rain garden and $125,000 rainwater harvesting cistern, meaning rainwater collected from the campus could be reused inside the building.

Again, board members said the additions wouldn’t save the district much but were environmentally important.

“If you consider we’re reducing reliance on a scare water resources, it begins to look a lot more attractive,” said board member Bob Hennessey. “And we know the community values water conservation.”

So far the board has chosen to fund the high school additions from about $2.6 million in state matching dollars not used in the baseline plans for the building. The district plans to also put some of that money in a contingency fund.

Gill said additional alternatives laid out by the design team — which include several other energy- and water-saving options as well as aesthetic improvements to the campus — could be funded with grants or with savings achieved if contractors’ bids come in lower than expected.

The district hopes to receive about $1 million in state energy grants and could sees as much as $211,000 in funding from Puget Sound Energy grants.

Islander Steve Haworth, who teaches environmental politics at Cornish College of the Arts and has followed the new high school’s design, said he was pleased to hear the school board voted to build a school that didn’t rely on fossil fuel and could eventually go off the grid.

“I’m glad they made the choice to take a stand that may cost a little more money in the short run, but is best for the environment and more most effective in the long run,” he said.

Hennessey said the board would continue to weigh their options in the coming months, considering that some of the money for green options could go toward other improvements as well, or simply not be spent.

“I don’t want to be green just for the sake of being green; I want to save the district money where it is going to improve energy costs … or have other environmental imperatives,” he said.

Hennessey said he thinks the community will be pleased at the energy efficiency of the new high school.

Wishik agreed, but added that everyone has different opinions when it comes to spending money on conservation.

“Some people will say we haven’t gone far enough, and some people will think we’re wasting money and have gone too far,” she said.