“The big design and development project of the next 50 years is going to be retrofitting suburbia,” architect Ellen Dunham-Jones says in an interesting TED talk.

Much of that work will be repurposing shuttered retail spaces — redeveloping dead malls and big box stores and turning empty parking lots back into wetlands, she says. For a good companion piece, in this interview Worldchanging’s Alex Steffen is much more skeptical that outer-ring suburbs can be “fixed.”