The era of super-tall towers on tiny sites in central Melbourne is over- unless developers are prepared to give something back to the community.

The Andrews government is moving to permanently restrict the heights developers can build to in the city.

It will introduce new laws dictating that a developer who wants to build to the borders of their site can only go to 18 floors.

But those that offer to provide community benefits such as a new park, public space within a building or affordable housing will be allowed to go higher.

The proposed "plot ratio" controls, which allow developers greater height or density in return for community benefits, are common in cities around the world.

Sydney, New York, Vancouver and Hong Kong all have lower ratios of land to density than Melbourne's new laws will allow.

Planning Minister Richard Wynne will on Tuesday release the final draft of the new central city planning laws for new developments in the CBD and Southbank.

The government plans to legislate the new rules in September, after independent planning hearings on the proposed changes. Mr Wynne introduced interim rules last year.

Mr Wynne said the new planning rules would "balance the need for growth with protecting the city as we know it".

When the interim laws were introduced last September, they allowed a more lenient 24:1 plot ratio.

The new laws will also lower the street wall height that will be allowed, from 40 metres to 20. Buildings will also have to be set further back from neighbouring buildings in a bid to ensure better daylight access and outlooks.

One planner said it was disappointing that the new rules did not include mandatory height limits, other than in a handful of areas such as near Parliament House and Spring Street, but expected the new density rules would curtail the rampant skyscrapers approvals on small sites seen since around 2009.

Another planner, James Larmour-Reid from the Planning Institute of Australia's Victorian office, commended the proposed changes, which he described as "reasonably sophisticated".

He also said the lowering of street frontages in some sites from 40 metres to 20 would bring "a bit more of a human scale", particularly in smaller city streets. "Forty metres is fine in the grand boulevards, but it's a bit overpowering in those little streets," he said.