Banking on Brooklyn’s real estate boom, the New York City Education Construction Fund is requesting proposals from developers for the site of P.S. 133, Park Slope’s William Butler School.

The block between Butler and Baltic streets along the recently up-zoned Fourth Avenue is being shopped around to developers as a profitable opportunity for residential or commercial development. The sale would be the first deal of its kind outside of Manhattan.

The 2003 rezoning of the neighborhood allows for maximum building of 120 feet along Fourth Avenue. The height threshold was instituted in order to encourage development in Park Slope while preserving the scale of the brownstone neighborhood.

In exchange for the right to build in the heart of Park Slope, the highest-bidding developer would be responsible for the on-site construction of a taller, slimmer building for P.S. 133. The building would be financed through tax-exempt bonds.

The new building to house the multicultural William Butler School, which currently has a student body of 273, would be built to accommodate up to 530 students. The terms of the agreement require that construction of the new building be completed before the old building is demolished.

The land, owned by the City of New York, will be transferred to the Education Construction Fund, which will issue a 75-year lease with no renewal rights for the residential portion of the development and a 40-year lease for the school portion of the project. While the school building that currently sits on the development site is not a New York City landmark, its demolition would have to be approved by the New York State Historic Preservation Office.