Most new homes being built in Canberra are connecting to the city's gas supply, despite plans to switch the network off within two decades.
The ACT government announced in August it would ban new gas connections this year, under its plan to ditch fossil fuels by 2045.
That decision had been flagged years earlier.
However, most property developers have stuck with gas, leaving new home owners facing tens of thousands of dollars in future electricity-conversion costs.
The ACT government says about 80 per cent of new houses, and 30 per cent of new townhouse and apartment complexes, have natural gas connections.
Larger buildings are a particular concern, as the costs of retrofitting them for electricity are far higher.
The ACT was the first Australian jurisdiction to announce plans to switch off gas entirely, though the Victorian government has a similar policy and several overseas cities have already banned new connections.
However, soaring gas prices were encouraging some Canberrans to switch to electricity before the ACT announcement.
About 67 per cent of ACT homes currently have a gas connection, down from 73 per cent in 2016.
Chief Minister Andrew Barr said gas prices would likely continue to rise in coming decades.
"All-electric buildings are not only a better choice for the environment, they're better for future building users and will save people money on energy costs," he said.
Retrofitting apartments will disrupt residents for 'months'
The government's gas discussion paper notes that building a dwelling with gas plumbing can cost the owner tens of thousands of dollars.
It says a gas-powered cooktop, water heater and ducted-heating system for a typical house costs about $9,000.
Uninstalling and replacing these with an electric induction cooktop, hot water heat pump and reverse-cycle air conditioner costs about $19,000.
Retrofitting apartment blocks poses extra problems, such as limited space for cabling and equipment.
The paper gives the example of an apartment complex with 370 units, fitted with gas cooktops and a central hot water system.
It estimates that retrofitting the complex with induction cooktops and individual heat pumps would cost about $14,700 per apartment, or $15,600 with an instantaneous water heating system.
"A new centralised instantaneous hot water system is unlikely to be feasible due to the additional power required for the system," the paper says.
"Similarly, centralised storage hot water is unlikely to be feasible due to engineering (weight requirements) and space constraints.
"This means a retrofit solution will impact the space within individual units.
"Retrofit work would be disruptive for residents and would require the building to be vacated, for a period of months."
Financial aid to help households, businesses go electric
The government initially said it would ban all new household gas connections "from 2023", but it has agreed with a Legislative Assembly committee recommendation to consult more widely.
It is now seeking feedback from households and businesses on several questions, including which properties, if any, should be exempt, and how the ban should be rolled out.
Energy Minister Shane Rattenbury said financial support was also available to help pay for electrical appliances and installation.
This included zero-interest loans of up to $15,000 for households, rebates of up to $5,000 for low-income homes, and similar grants for businesses.
The government's consultation closes on April 20, and it plans to enact its ban on new gas connections by November.
