In many ways, the 82-unit Linden Lake Senior Apartments on Norcross Road looks like any new building - but on its roof, behind its walls, and even in its sidewalk concrete, the developer incorporated the latest "green" techniques to stretch consumers' dollars and reduce pollution.

"I like the energy efficiency of it all," said Helen Constantino, 63, who came from nearby Pine Hill seeking relief from maintaining a single-family house.

Results from developer Conifer Realty's energy-saving innovations are being monitored by state and federal loan agencies, which helped fund the project and could give priority to similar ventures in the future.

Conifer predicts that residents will save 15 to 35 percent on their utility bills, compared to tenants of similar-sized apartments elsewhere. The first occupants moved in last month: Exact savings will be clear after a few months' bills come in.

Those savings will come from Conifer's energy-conscious building techniques: insulation, high-quality windows, solar panels and EnergyStar appliances, said Michael J. Brown, program marketing director for New Jersey's Clean Energy Program.

In addition, the builder used environmentally friendly products such as low-pollutant paint and recyclable and durable flooring. The sidewalk is designed to filter water instead of creating polluting runoff.

"Linden Lake combines redevelopment, brownfields reclamation, affordable housing and energy efficiency, but most important, 80 senior citizens call it home," said Charles M. Lewis, vice president of Conifer Realty.

The firm, which has local offices in Mount Laurel, has developed affordable housing communities in New Jersey, Pennsylvania, New York, Maryland and Ohio.

Thanks to the summer sun, the 48-kilowatt solar system at Linden Lake has met the three-story building's hot-water needs without help from the natural gas-powered backup. It also provides electricity to cool and light the common room, lobby and hallways. The system produces enough energy in one week to power an average-sized house for a month.

Even the toilets are environmentally friendly, conserving water by offering two flush options.

Conifer Realty financed the $13.6 million project with help from $1.6 million in federal, $3.1 million in state and $500,000 in county funding, as well as federal affordable housing tax credits and state solar energy rebates, Lewis said.

Over the next year, the state and federal loan agencies will compare energy expenses at the Lindenwold project to those at one of Conifer's older multifamily developments, Lewis said.

Marge Della Vecchia, executive director of the New Jersey Housing and Mortgage Finance Agency, said that if residents' utility savings proved significant, future developers who incorporate green features their projects would likely get loan preferences.

Lindenwold's decommissioned sewage treatment plant was a danger to children and a magnet for vandals before redevelopment began four years ago, Lindenwold Mayor Frank DeLucca said.

"Senior citizen housing is every municipality's priority," he said. "It doesn't impact the schools or services. It lets adults transition from their homes and still live in town."

Linden Lake charges $597 monthly rent for a one-bedroom and $716 for a two-bedroom. Forty percent of the units are designated for those with an annual income of $60,000 or less.

Rents in New Jersey average $1,085 for a two-bedroom apartment, among the highest in the nation, according to the New Jersey Builders' League.