■ It seems each state government wants to leave its mark with new planning rules and city boundaries. How does Plan Melbourne differ from previous plans?
It is more similar than different to previous plans such as the Labor government's Melbourne 2030. With one of the world's largest cities in geographic terms, spanning nearly 10,000 square kilometres, recent blueprints for Melbourne have attempted to limit Melbourne's sprawl; this plan is no different and talks about setting a firm boundary. Easier said than done.
The new plan also wants to use what we have in a better way; more housing in suburbs that already have services (even though the plan also seeks to protect the suburbs from ''inappropriate development''); build near activity centres and employment clusters - government calls it ''common sense'' planning. This plan, the government tells us, is different because it will be delivered with the help of a new Metropolitan Planning Authority.
■ But doesn't local government have the power to approve and oversee new building?
Local government does strategic plans for their municipality and small stuff - house renovations and small developments, that are often what make residents and builders angry. Local governments are finalising new planning zones that will make clear what can be built where: how many homes on a block and how high. Plan Melbourne highlights activity centres and employment clusters where medium density development is expected. The rules governing setbacks, overshadowing and other aspects of design - ResCode - remain unchanged.
■ Will the new authority change VCAT's controversial role in approving and rejecting planned developments?
No. VCAT remains Victoria's planning umpire.
■ Planning is fraught with conflicts between developers and community conservatives, governments who want a growing economy and tax take and not-in-my-backyard residents. How does Plan Melbourne handle the politics?
According to one senior planner, the losers are residents in the growth areas, where there are no firm commitments to deliver community facilities and public transport services; the winners are those in the established middle suburbs. Will there be fewer planning disputes? In some places, yes. Plan Melbourne and the Planning Minister want to bring certainty to planning in Victoria. If you can afford to live in a leafy suburb with a neighbourhood residential zone you do not have to worry about a six-storey tower going up next door.
Likewise, if you are in growth zone or activity centre, don't be surprised when workmen turn up nearby for that new multi-storey development. This document and the new zones are more prescriptive than the past. The uncertainty may come in the general residential zone that leaves the door open to challenge.
■ So, what will Melbourne look like in 30 years under this plan?
Teeming. Under current projections there could be 7 million people in the city - up from 4.3 million now. The CBD would have expanded massively with skyscrapers from Footscray Road to South Melbourne and Carlton. More train stations will have medium-density retail and apartment developments and there will be more freeways encouraging more people to drive, bike paths and maybe a new train line to the airport.
■ Where will the increased density be concentrated?
Melbourne's west, north and south- east will take up the bulk of the city's population growth to 2031. The south-east could have 480,000 more residents, the north 470,000 and the west 430,000. These areas still have undeveloped land within the urban growth boundary. It is also expected councils in the eastern and south-eastern suburbs will push for tougher housing zones to restrict development. Glen Eira has already locked up about 80 per cent of its residential area with the neighbourhood housing zone. Where will the new housing for the 480,000 new residents occur if vast tracts of residential land are zoned for little or no change?
■ What does Plan Melbourne have to say about how new infrastructure - roads, public transport, schools, and hospitals - will be planned and funded to keep pace with increased density in growth areas?
Big strategic plans - particularly for billions of dollars worth of infrastructure - are sometimes referred to as ''wish visions'' by the sceptical. The former Brumby government in 2008 famously released a largely unfunded $38 billion transport plan. Plan Melbourne faces the same risk. It is not a budget document; it is an ambitious plan. There are colourful lines going everywhere. The East West Link looks likely - it has funding from tolls and billions of dollars in federal money.
After that it gets a bit murky. Plan Melbourne says the Melbourne Rail Link from Melbourne Airport to the city, South Melbourne and South Yarra will become ''progressively operational'' from 2017-25. Less than 10 per cent of the estimated $11 billion cost is in the budget papers for the next four years. In the next three years that dives below three per cent. The budget papers say there is $40 million for this project in 2014-15 and remaining expenditure of $10.96 billion with an estimated completion ''from 2023-24''. With the state facing increasing funding pressure from federal government cuts it is difficult to see how this project will be funded.
■ Will Plan Melbourne finally give clarity and certainty - to those who want to build and to residents - as well as flexibility in housing options and affordability?
Yes. Plan Melbourne and accompanying zones make it clearer what can be built and where. Some ambiguity will remain as some developers push limits and some residents oppose any development. Will it be more affordable and will there be more housing choice? Unclear until zones are finalised but there are some worrying signs that choice may be reduced and housing will become increasingly unaffordable to buy or rent for a growing number of households. Suburbs may be locked up - gated communities where only those rich enough to buy a large family home can live. As these middle suburbs continue to accommodate an ageing population there are likely to be fewer choices available for these people to age in their suburb. Those calling for minimal development such as apartments and town houses may feel differently when they want to downsize as they retire or have their children enter the housing market close by.