Community groups have called on the government to rethink the number of apartments, saying townhouses are more in demand than one-bedroom apartments and that developments should be no more than three storeys in the suburban areas.

The government is moving public housing tenants out, demolishing the flats and rezoning the blocks as RZ5 – allowing developments as high as six storeys.

At Red Hill, the 144 public housing units are being replaced with as many as 550 or 600 units.

Gowrie Court currently has 72 two-bedroom units. Residents believe numbers will be upped to as many as 180.

The Stuart Flats have 146 units – 29 bed-sitters and 117 two-bedroom units. Residents say the government is proposing 500 replacements – 200 one-bedroom units, 224 two-bedroom units and 76 three-bedroom units.

The plans were "an egregious over-development" requiring massive parking structures, Inner South Community Council chairman, Gary Kent, wrote in a submission to the planning directorate.

He also felt that six-storey developments should be restricted to town centres, as set out in the Territory Plan, and not allowed in the middle of suburban zones.

The market for one- or two-bedroom apartments was reaching saturation, and a switch to larger three- and four-bedroom apartments and townhouses would attract "the wealthier downsizing segment", Kent said, accusing the government of trying to maximise the cash it could make from the blocks.

"What should have been a reasonable process of property portfolio management has been transformed into an apparent attempt to maximise the cash return to the government at all costs."

The Red Hill flats were built in 1960, Gowrie Court in Narrabundah in 1959, and the Stuart Flats near Manuka in 1959.

Kent said that residents recognised that all three should be demolished and replaced, and the program was a chance to use profits for new and better public housing. But they were also concerned about the extent to which public housing tenants were being moved out, with the government initially suggesting 10 to 15 per cent of public housing in new developments but now refusing to commit to a specific percentage. The number "appeared to have declined to zero", but long-term residents should have the right to stay in the suburbs if they wanted to, he said.

The council called for the number of townhouses and bigger apartments to be increased in all of the developments. It called for building heights to be reduced and intensity decreased.

In the Stuart Flats case, it also raised concerns about the trees on site, with one tree classed as having "exceptional value", 14 high value, and 41 medium value. The council suggested developers could be required to pay $10,000 for every medium-value tree removed, $25,000 for a high-value tree, and $50,000 if the exceptional value tree was removed.

The Griffith Narrabundah Community Association president John Edquist said the Gowrie Court redevelopment was much bigger than initially planned, with too much focus on small apartments. The 180 units would need 270 carparks, which meant underground carparking – adding to costs, restricting space for deep-rooted trees and reducing the attractiveness of the development to older people.

He also raised concerns about the impact on Manuka parking of as many as 850 people living in the redeveloped Stuart Flats.

Red Hill Residents Group chairwoman Melissa Bennett said the community was completely opposed to the planned density at Red Hill and wanted heights limited to two or three storeys.

"The clear preference from the community has been completely ignored," she said. "They're maximising as much as they can without any thought to infrastructure."

Consultation on the Red Hill development has been extended until the end of August.