For decades, Melbourne's planners, architects and politicians have been in agreement that the city's voracious urban sprawl should stop.

Yet, the city has ploughed ever outwards, as housing estates swallow up grasslands and farms, and freeways are built to connect the new suburbs.

Simultaneously, the city's prosperous middle suburbs have been left largely untouched.

Now, a major three-year, federally funded report – written by architects, urban designers, councils and several state government departments – has explored why little has changed in how Melbourne develops.