Quality infill projects of Canberra's past offer a guide to how to house Canberra's growing population within its existing footprint, an effort that will need more than more dual occupancies, the Greens believe.
Greens planning spokeswoman Jo Clay said unit developments along Howitt Street, Kingston, demonstrated what was possible when higher medium-density housing was permitted.
One apartment building, at number 12, balanced the need for sunlight, space, greenery and was home to a variety of people, she said.
"We've got three-storey apartments here and there's a really vibrant mix of people who live in this area. It's close to shops, it's close to really good public and active transport," Ms Clay said.
"There are a lot of features about this that let people live well in Canberra."
Ms Clay said housing examples from older infill areas showed a path forward to a more compact city that did not compromise on housing quality or amenity.
"I'm reassured to see that we have so many great examples from the '80s that show us it can be done, and I'm sure we've got some great new ideas that we haven't even thought of," she said.
Ms Clay said the Greens had supported calls for more so-called missing middle homes - the kind of development between free-standing houses and high-rise blocks of flats, like terraces, duplexes and walk-up apartments.
"We would also support zoning reform that allows dual occupancies. But when we looked at the issue really carefully, we realised the issue is trees and green space," she said.
Ms Clay said the Greens would ensure protections for trees and green space, enacted under the old planning system, would be brought across the new system.
But the answer to the question of how to provide high-quality urban infill housing would involve more than just dual occupancies.
"When you try to put more living spaces on smaller blocks individually, you actually lose a lot of your trees and green spaces. When you consolidate blocks, like we have here in Howitt Street, and you put carefully designed apartments or townhouses [on the site], you've actually got room for these beautiful shared courtyards and a great street layout," Ms Clay said.
Ms Clay also said the Greens wanted to set city limits, which would ban development outside Canberra's existing footprint.
"Part of that means we need to work out where our people live and where they will live," she said.
The government is expected to unveil the technical specifications and district strategies for the new planning system, three months after enacting the enabling legislation, in the coming week.
Last Monday, Chief Minister Andrew Barr flagged changes to RZ1 zoning rules, which cover much of suburban Canberra and restrict housing to detached homes.
"What's allowed in RZ1 is likely to change in a way that is consistent with the path of gentle urbanism that I've been talking about for many years now," he said.
Urban infill has long been one of the most contentious planning issues in Canberra, with residents concerned about the loss of trees, parking, solar access and the urban heat island effect.
But Ms Clay said pointing to quality urban infill projects - particularly in areas of the inner south and the inner north - could allay those fears.
"We need to make sure that we show people what's possible and then we need to make sure we get the regulatory and commercial settings right so that Canberra actually gets those outcomes," she said.