On Primary Day, Brad Lander parked himself in front one of his favorite places in the 39th district: a corner on the edge of Kensington that is surrounded by a school, a park, and a library.

“It’s a place of great civic energy,” he said, pointing out the Immaculate Heart of Mary Church across the way. “Not a place I think I got a lot of votes from, but still…”

That corner, though, turned out to be crucial in Lander’s primary campaign to replace public advocate-elect Bill de Blasio in the Brooklyn brownstone belt district. From that corner, Lander caught voters as they emerged from the Fort Hamilton subway stop, and persuaded them to take minute to pop over to the schoolhouse on their way home and vote.

Lander went about his campaign methodically, slowly gathering support from some of the local political heavyweights, including Rep. Jerrold Nadler, State Sen. Daniel Squadron, and Assembly Member Dov Hikind, as well as the Working Families Party and the New York Times.

Lander comes to the Council with more of an activist/academic pedigree than a political one. He served for six years as the head of the Pratt Center for Community Development, a public policy institute designed to aid local planning efforts. Prior to that, he led the Fifth Avenue Committee of Park Slope.

“I see my service on the Council largely as an extension of the kind of civic advocacy work that I’ve been doing,” he says. “Hopefully as a Council member you get your phone calls returned a little quicker.”

His new colleagues say they expect Lander to quickly emerge as one of the leaders on the Council.

“He’s going to be great, I think,” said Council Member Gale Brewer, who has a relationship going back years with Lander. “He’s really smart, and he understand the struggles that families go through, and he understand the solutions.”

On the Council, Lander says his focus will be on education, particularly around parental involvement, and on building what he calls “sustainable neighborhoods.”

The remnants of an unsustainable approach to neighborhood building is made plain a few blocks away from Lander’s favorite corner, across a small pedestrian bridge over the highway into the neighboring community of Windsor Terrace.

There, Lander points out a half-built brick home that developers abandoned once the economy turned sour, destroying a mid-block single family home in the process. A homeless Vietnam War veteran has built a small shed against some of the rubble and moved in to the makeshift home.

Finding a home for the vet, and cleaning up the blight are some of his immediate concerns, he says, but changing city policies so that such properties do not linger is the longer-term goal.

This kind of failure to clean up after the housing bust comes into larger focus down the street: the skeleton of a 7-story, 102-unit building that looms over much of the three- and four-story neighborhood.

Historic stables that housed the horses riding around Prospect Park were destroyed to construct the building that constructed before the city could rezone the area. Now it sits empty, surrounded by blue construction fencing. The building is in foreclosure. The equity investors are in bankruptcy, and the bank has been liquidated.

No work has been done for months, and residents fear the building will become a safety hazard if it remains vacant.

Lander says that though not much could have been done to prevent buildings like it from going up, the task of the city now is to clean up properties left unrealized by the housing boom through a combination of higher taxes on vacant land and Department of Buildings regulations.

“The bank, the developer, the investors all made very bad decisions,” he says. “Now it’s time for the city to assert itself.”