A new rectangular stadium in Civic could be delivered three years earlier through the adoption of the same model Greater Western Sydney plans to use in an $800 million redevelopment of Manuka Oval.
As Fairfax Media revealed, the GWS Giants announced on Wednesday plans to integrate the historic oval with the Manuka and Kingston Foreshore precincts.
The project, which will be subject to public consultation before seeking ACT government approval, would be funded by the developer, Grocon, and the Giants, and requires no government investment.
A 200-300-room hotel, about 1000 apartments and an underground carpark for about 350-450 spaces all form part of the plan, which is expected to take about eight years to complete.
The ACT government had hoped to have a new Civic Stadium by 2020, but their asbestos clean-up of Mr Fluffy houses has pushed that back until about 2025.
Any government savings from private enterprise funding the Manuka project is not expected to be enough to bring forward that completion date.
But Brumbies chief executive Michael Jones said adopting the same model could see it built by 2022.
Jones, who said the Manuka idea was "really clever", said preliminary discussions had been held with both the Canberra Raiders and the Brumbies' sponsor Aquis - who are developers - for a similar model to be used for a covered Civic Stadium.
Not only could the development include a covered stadium with a capacity of between 20,000-30,000, but could also be linked in with the proposed new casino.
But before the stadium can begin, a new pool needs to be built, with the stadium's likely site on the pool's current location, and Parkes Way also needs to be moved slightly.
But Jones felt it could still be finished earlier.
"It's a pretty good announcement and will be good for Manuka," he said of the Giants' proposal.
"Yeah I believe so [the Civic Stadium could be built sooner] ... there is value in getting access to more land that close to the city - and it would be prime land because it is slightly elevated with views across Commonwealth Park.
"It's very embryonic at this stage, but we've had discussions over the last 12 months.
"I don't think it's going to happen this decade, but from 2020 is a realistic time frame and the construction of it would take a couple of years so it would be 2022-23 before you actually have everything up and running."
The Manuka Oval proposal would see capacity kept at 15,000, with permanent stands to replace temporary seating and new roofing to cover about 80 per cent of seats.
Shepherd said they decided against increasing capacity due to cost and because "it's better to be sold out than half empty" - although that could be an option in the future.
The Giants are almost halfway through a 10-year, $23 million deal with the government to play three AFL home-and-away games at Manuka until the end of 2021.
Shepherd said there could also be the option to bring more in the future.
While GWS currently play eight home games in Sydney, they are only contractually obliged to play seven - meaning there's always the option to bring one more game to Canberra each year.
Shepherd said there would be "some inconvenience" with reduced capacity during construction, but guaranteed all games would go ahead.
"I've had experience of doing this before, in building in a live stadium. There will be some inconvenience obviously, you cannot deny that, but you try and phase it so that the ground can continue to operate completely and you try to phase it to fit in with major events," he said.
"That's a little bit less efficient than closing it down for a couple of years and doing the job, but I think it's important that you maintain continuity in terms of the venue."