It's been empty since 2005, but there's now competition to buy the old Northrop school building on the South Side.

Neighbors from the area listened this week as two teams pitched competing proposals to buy and rehab the building at 1611 E. 46th St. Both groups also hope to build on the playground area of the property, one now and one later.

One proposer was a familiar face to many. United Properties returned after making a proposal earlier that wouldn't work without city subsidies, which were not forthcoming. But this time, it said its revamped proposal will work without that because it's not planning to raze the school.

That's because United proposes to rent the existing 1923 building to a start-up charter school, which hopes to open next fall. It also plans to build about 65 units of new cooperative housing aimed at seniors in the area who are ready to sell their homes. That's down from the 106 units it proposed earlier when it planned to demolish the school.

The other proposal comes from a growing network of highly regarded South Side charter schools that serves a student body that's mostly Latino and low-income.

That's Hiawatha Academies. It operates one elementary school in the school district's former Morris Park school in the city's southeastern most corner, and one middle school in a former parochial school in the King Field neighborhood. Now demand for spaces is strong enough that it wants to launch a second elementary school opening in 2014, ahead of its previous timetable for expansion. It would eventually grow to 390 students once all grades are in place.

Eli Kramer, the network's executive director, said the school is offering $1 million for the property and would invest $3-3.5 million in rehabbing the school, adding an extension and sprucing up the grounds. Kramer said the school needs a new roof and windows, plus some ceiling and floor work He said that eventually Hiawatha would like to discuss adding a middle school on the current playground when demand warrants.

United's Mark Nelson wasn't as specific about how much his team plans to offer for the building and spend to renovate it, but his purchase offer is believed to be somewhat higher..

Although the school board is getting assistance from the city's development arm in evaluating the financial feasibility of the two proposals, the board will make the decision.

The United property would address the desire expressed by the neighborhood in earlier brainstorming for reuse of the site that senior housing be created. Another advantage to the United proposal is that its housing development will create tax base that the Hiawatha proposal won't.

The Hiawatha proposal rests on the school being owned by Charter School Development Corporation, a multi-state charter financing nonprofit. That's because Minnesota law prohibits charter schools from owning their buildings. The charter would pay the development corporation through annual lease payments, for which state aid is provided to charters. But nonprofits pay no property tax so that may be one factor influencing the board.

However, Hiawatha has been moving toward a closer relationship with Minneapolis schools, and Northrop is in the middle of the area from which Hiawatha draws most of its students. Moreover, Hiawatha offers a charter operation with a proven track record, while Arches Academy, United's proposed tenant, is a startup. Another factor is that United would need to presell 60 percent of its units to qualify for the HUD financing it plans to use, something that helped to stall its previous proposal. But it has created similar developments in suburban cities..

Arches is being created by Angela Mansfield, a Minneapolis schools teacher with an impressive educational resume. She's working with Charter School Partners, a nonprofit group that seeks to replicate high-quality charters.

The school board is expected to act later this winter on the recommendation of its staff on which group should get the site..