New York City has seen a drastic physical transformation during Michael Bloomberg's 12 years in office, and the driving force behind some of those signature changes - the remaking of the Brooklyn waterfront, the construction of the East River esplanade, and the ongoing Hudson Yards project - was Amanda Burden, director of the Department of City Planning and Chairwoman of the Planning Commission. 

She's one of the longest serving members of his administration, and her time as a member of the commission goes back even farther, to 1990.

Reflecting on her time in office, Burden talked about her greatest accomplishments (the High Line), the planning challenges the city must contend with in the future (the effects of global climate change) and her sometimes prickly relationship with developers.

She also had some advice for Mayor-Elect Bill de Blasio, who has a goal of creating 200,000 units of affordable housing. 

"The challenge for the new mayor is to persuade communities to accept additional height and density, so that more affordable housing can be accommodated and that can be a big challenge for him. It certainly was for us," Burden said. 

Burden is joining the outgoing mayor at Bloomberg Associates, which will help governments around the world implement projects based on his signature policies in New York.