Haverhill's Hill View Montessori Charter School has just purchased a building for $2.7 million in the Ward Hill section of the city as the new home for its growing student body.

That has produced predictable complaints from some quarters that this is sucking yet more millions away from the city's struggling public schools.

It is not.

It has been said many times, but apparently needs to be repeated many more times — charter schools are public schools. To say that Hill View is draining money from the public schools makes as much sense as saying that Haverhill High School is draining money from the public schools. All the public schools are supported by taxpayers.

But charters get less support than others. Neither local nor state taxpayers are paying for this building. Charter schools are not eligible for school building assistance. Since 2004 they have received a small per-pupil allotment for facilities, to make up for funding cuts due to a changed formula, but they get no funding to buy or build new buildings.

As Dominic Slowey, a spokesman for the Massachusetts Charter Schools Association puts it, "The taxpayers are essentially getting a new public school building for free."

Hill View has been operating in three buildings — its 272 students attend the former Bartlett School on Washington Street, Temple Emanu-El on Main Street and Little Sprouts School on West Lowell Avenue. Its new home, a 50,000-square-foot, two-story building that formerly housed International Totalizing Systems, has room for 300 students, including space for a library, gymnasium, and art and music rooms.

Hill View, which opened in 2003, just recently had its charter renewed for another five years. It is obviously providing quality education. Its move into a better campus will improve that quality.

It is an asset, not a drain on public education.