The Dickson flats on Northbourne Avenue.

The Dickson flats on Northbourne Avenue. Photo: Graham Tidy

With the transformation of Northbourne Avenue set to begin, ACT Heritage Council chairman Duncan Marshall warns the government should only demolish the public housing blocks if there is no reasonable option to preserve the historic buildings.

The government plans to replace the 424 units on either side of Northbourne with more than 1100 apartments, starting with the Dickson Towers bedsits near Dickson, which it is preparing to demolish. A 160-apartment complex is to replace the three buildings, which between them contain just 21 bedsits.

The move is part of the plan to transform the city to Gungahlin corridor for the tram line - the biggest infrastructure project built by an ACT government.

On Monday, the sell of the rail line begins in earnest, with a pop-up shop in the bus interchange featuring detailed plans and asking for feedback on questions of design, such as tram stops. A mail-out will also go to all households in the inner-north and Gungahlin.

Mr Marshall said the Heritage Council was yet to see the government’s plans but expected a consultant’s report to suggest there was no feasible alternative to demolition of the Northbourne housing.

Five separate housing types, stretching 500 metres on both sides of Northbourne Avenue, built in the 1960s, are considered significant for their post-war Bauhaus-influenced design and the prominent architects involved in their design.

The government plans to retain just 17 De Burgh Street buildings on the Lyneham flats site for adaptive re-use, as well as keeping the original open spaces and patterning.

Mr Marshall said that was ''better than nothing'', but only a fragment of the original range of housing.

While the council was still considering the nomination to the ACT Heritage Register, Mr Marshall said there was ''no doubt in my mind that the nature and scale of change will be very substantial and the impact will be very high''.

''I am disappointed that there does not seem to be an option available which would involve sympathetic adaptive re-use and the retention of a large proportion or the whole of the complex,'' he said.

While the council expected heritage values to be retained, the exception was where there was no ''feasible and prudent option'' to retain them.

''This is a very difficult and very complex development issue involving substantial heritage qualities, so it’s a very unwelcome situation where we have to contemplate the possibility of demolition," Mr Marshall said.

"But our role is to really rigorously test the arguments that are going to be put to us to make sure that suggestion, that there are no feasible and prudent options for the retention of this precinct, that that is genuinely so.

"We can’t turn situations on their heads where theyare strong and powerful problems which can’t be solved ... but we’re the ones that need to argue the heritage arguments and try to achieve the best possible outcomes in the circumstances.''

Mr Marshall said it was likely  "we will end up with a very limited amount of the fabric being preserved'', but the council would rigorously test the government’s argument for not keeping more.