The government has published a set of discussion papers which flag possible changes to the territory's planning system.

The release of the discussion papers represents the latest step in a major review and overhaul of the rules governing what can be built and where in Canberra, which has been underway since early 2019.

The government had hoped to start implementing changes in early 2021, but that appears unlikely to happen given further consultation is scheduled in the new year.

The overarching ambition of the reform is to create a simpler planning system which is focused less on rules and more on "outcomes" - essentially higher-quality buildings which are appropriate for their location.

The discussion papers, which were informed by preliminary consultation with industry and other community stakeholders, set out the case for changes to a system which has been criticised by residents, industry and even the ACT planning minister Mick Gentleman.

Mr Gentleman said the ACT needed a planning system which could support the city's growth while protecting its character and diversity.

The government is planning for 100,000 new homes to be built in the nation's capital in the next 25 years, with 70 per cent of those to be constructed in established suburbs.

One of the papers said development controls set out in the territory plan were rigid, which meant government planners were forced to reject applications for projects which "on the surface seem to be logical".

Under a suggested new approach, the system would encourage development proposals which fit a broader description, such as "low rise and in keeping with the scale of surrounding development".

"Existing development controls, in the eyes of the community, fail to promote high quality development," the papers stated.

"Expressing controls in terms of outcomes provides a stronger message in terms of the type and quality of development the planning system is seeking to facilitate and gives the planning authority greater scope to consider more innovative proposals."

In a bid to encourage higher quality proposals, developers might be allowed to exceed height and density guidelines if they met certain criteria, such as including large public spaces on their block.

However, the special dispensation wouldn't be allowed if the extra height or units meant the development would have a negative impact on neighbouring properties.

The ACT government is alert to potential community concern about allowing for more discretion and flexibility, noting that "predictability, consistency and certainty" were valued parts of the system.

The paper said those issues could be mitigated by clearly setting out how the new "performance-based" guidelines would be interpreted.

One of the six papers flagged changes to the development assessment system, which was described as complex and inflexible.

In one example of the system's flaws, it noted how the assessment pathway - or "track" - for applications was pre-determined by the zone in which it was proposed.

"Therefore, in practice, a single-storey and single-use development is considered in the same assessment track as a 27-storey mixed-use development," it said.

The paper suggested replacing the three existing assessment tracks - code, merit and impact - with two pathways: one for simple applications and the other for complex proposals.