Lower Merion School District board president Lawrence Rosenwald says the prosperous and high-achieving district has to have a new high school - and soon - that allows it to keep its "commitment to be the best district in the state."

In keeping with that viewpoint, district officials and architects have designed what they call a "state-of-the-art" proposed new Harriton High to replace the current 49-year-old school with one on the same site that they say will put the building on a par with the best in the United States.

That means, they said, smaller classrooms, (25 students per, instead of the standard 30) more science, arts and special-education rooms than most schools, many more rooms for seminar-size instruction, eight teachers' departmental planning rooms, and a small open-stage theater. There are even wider than normal halls, to cut down on conflicts resulting from what officials call the "cattle-chute effect" as students go from room to room.

The school board is scheduled to vote on the $102.9 million project tonight. If approved, the school would open in fall 2009; a new Lower Merion High School in Ardmore is also in the planning stages.

But before the vote, the board will have to face the criticisms of a vocal group of residents, members of a group called Budget Reform for Student Learning. The group says the proposed building has gone $4.7 million over the board's own "not to exceed" maximum because it was designed to be much too large, at least in part to avoid having to put the plan to a district-resident vote.

Rosemont resident Stephen Gleason said in a recent interview that the proposed 1,250-student, 328,000 square-foot Harriton High would have by far the largest per-student square footage of any built in the area in recent years and by far the largest per-student cost.

"I think what parents need and students want is their money going for smaller classes and excellent teachers, not oversized buildings," he said.

Gleason said he believed it was only by adding unnecessary classrooms to the plan for Harriton and by overestimating projected enrollment that the district had avoided being required to hold a referendum under a 1973 law - Act 34, the so-called Taj Mahal law.

The law requires voter approval if construction costs exceed a complex state-established "Aggregate Building Expenditure Standard" limit. The limit is based on projected enrollment, building size and construction costs, with differing allowances given for instructional spaces, such as classrooms, and non-instructional spaces, such as an auditorium, gymnasium, cafeteria or school lobby.

By adding unnecessary classroom space and planning for more students than the state projects, Gleason said, Lower Merion school officials have enabled the district to design a far larger facility than necessary without exceeding the spending limit and triggering a public vote.

Even now, construction costs for the Harriton project will be only $1.9 million less than the state-determined threshold that would automatically trigger a referendum.

Gleason said he wanted the board to conduct a referendum, even if one was not required, and put the cost and size of the new Harriton building "to a vote."

"If the public says yes, that's the process - I walk away happy," he said.

Board and administration officials contend that the extra space is needed to support Lower Merion's extraordinarily broad and deep instructional offerings.

The new building, they said, has to have space for Advanced Placement and International Baccalaureate programs that offer more small-group, advanced courses for students than most schools. It would have far more arts and science offerings than most schools, would have an additional small theater along with the standard one in the auditorium and would have smaller classrooms and lots more rooms for small-group gatherings, for special education instruction and for teachers' planning use than most schools have. But they said emphatically that the building would not be a Taj Mahal.

"When people see this school, they will certainly not say, 'Wow! This is extraordinary,' " said Lower Merion Superintendent Jamie Savedoff. "It's a good, functional high school building with the emphasis on science classrooms, special education, individualized instructional areas and the arts; that's where we put the focus."

District officials say the per-student cost and size of the new school are high because its projected enrollment of 1,250 students is smaller than those of most area high schools. While its enrollment would be smaller, they said, the size of its gymnasium, for example, would be roughly the same as it would for a school with a significantly larger student body.

"Each educational program is so varied that the yardstick to measure a building . . . is does it fulfill the educational program of the school district it is in," said James Clough of KCBA Architects, which designed the proposed Harriton building. "I don't think you can go across the board nationally and pick a square-foot per-student figure that has any real meaning."

As for overestimating future high school enrollment, the Pennsylvania Department of Education projects a combined enrollment of 2,098 in 10 years for the two Lower Merion high schools, while the district projects a higher enrollment of about 2,500.

District officials said high school enrollment this year is about 2,470, and they say they expect the new schools to draw some new students from private schools.

"It's common to have differences about these kind of figures; it's nothing unusual," Clough said.

The debate over what to do with the two high schools is not new. In the late 1990s, the school board leaned toward renovating Harriton and Lower Merion, instead of building new schools. In May 2001, it changed course and approved the idea of two new buildings, but the election of several new board members later that year who questioned the plan led to another round of discussions.

In August, the board unanimously agreed to put Harriton out for construction bids. But in February, the bids came in almost $7 million higher than the board had hoped for. The construction was put out for bids again with some technical changes and changes in materials that were designed to elicit lower offers. One bidder responded, with a proposal that is still $4.7 million higher than the district had wanted. It is that bid that the board will vote on tonight.

Contact staff writer Dan Hardy at 610-701-7638 or dhardy@phillynews.com.