This week’s guests are on the frontlines of making cities sustainable with their work on housing, mixed use development and Main Streets.

Jonathan Rose has been called the father of the green affordable housing movement. His projects in the South Bronx and in Harlem are showing how green buildings ought to be for everyone. The national real estate firm he founded, Jonathan Rose Companies, collaborates with cities, towns, and nonprofits nationwide to develop projects that are both green and socially responsible. Its mission is to repair the fabric of communities.

Brian Goodman is renewing Boston’s neighborhood commercial districts through its Main Street program, demonstrating that old does not necessarily mean disposable. Brian manages Mainstreets WiFi and Boston Community Change and he has been a Peace Corps volunteer in Bulgaria, an entrepreneur, and an MBA student at Babson College.

Smart City is a syndicated, weekly hour-long public radio talk show that takes an in-depth look at urban life: the people, places, ideas and trends that affect us all. Host Carol Coletta talks with national and international public policy experts, economists, business leaders, artists, developers, planners and others on the pulse of city life for a penetrating discussion on urban issues.

Smart City is broadcast at 6 a.m. Saturday and Sundays on WKNO-FM, but it is also webcast and podcast. For the webcast, times for the broadcast in other cities and to sign up for the podcast, visit the website.

Note: We’ve received numerous emails asking about the change in the broadcast time of Smart City in Memphis. We’re extremely grateful to WKNO-FM for their instrumental role in making it possible to have this program in the first place and we will always remain so. In answer to emails, however, we did want to respond: If you would like the time moved to the later time that it previously had (as many of you have said), please contact the radio station program director.