Readers respond to the notion that Melbourne will become a megacity of more than 10 million people by the turn of the century.

Planning Minister Sonya Kilkenny draws a policy battleline about our city’s future shape, as we investigate how and where to house Melbourne’s booming population by 2101.

Readers respond to the notion that Melbourne will become a megacity of more than 10 million people by the turn of the century.

We asked planners what Melbourne would look like if it went up or out by 2101. Explore the interactive.