An ACT government internal briefing paper raises the option of buildings soaring to 50 metres high in Northbourne Avenue.
The possibility, though, is being played down by authorities, with City Renewal Authority interim chief executive Gary Rake saying the government is not considering 50 metre height limits at the Macarthur House site.
The height limit at the moment in Northbourne Avenue is 32 metres, but tender documents released in a call for expressions of interest for demolition of Macarthur House last week envisage 50 metres at key intersections.
Asked to confirm that Macarthur House and the other Northbourne blocks being sold under the asset recycling scheme will be replaced with developments no higher than 32 metres, a spokesperson for Chief Minister Andrew Barr said only, "Developments are required to comply with the height limits set by the National Capital Authority."
He gave the same answer when asked what special planning rules were being considered for the new Northbourne Avenue special precinct. But he said the government would outline its vision for the Northbourne Avenue corridor and city "in due course".
A National Capital Authority spokesman said it had discussed Northbourne height limits with the ACT government but no request had been made. Any change would go to community consultation, he said.
The 50 metre option was revealed in a traffic assessment for the Macarthur House demolition by consultant Cardno, which said the Land Development Agency had put three options in an "urban renewal discussion paper":
- Redeveloping the Macarthur House block, on the corner of Northbourne and Macarthur under the rules of the Territory Plan as it stands, with four apartment buildings and basement carparking.
- Reducing the setback requirements near the intersections, applying a 10 metre setback instead of 25 metres.
- Increasing the building height from 32 to 50 metres, as well as reducing the setbacks. A 12-metre limit would apply to parts of the buildings that fronted residential areas. "The new highet restriction will replace the 32 metres maximum building height for intersections of Antill Street and Mouat Street as well as Wakefield and Macarthur Avenue, as per the brief provided by the LDA," the option says.
The traffic modelling is based on the 50 metre option.
But the status of the option is unclear. The City Renewal Authority will not release the brief, describing it as a "draft internal working document" and "preliminary analysis" that "considered the impact of various development scenarios".
Traffic assessments "regularly use a highest case scenario for modelling purposes", Mr Rake said.
He also referred to an Environment and Planning discussion paper in January 2016 which "considered the potential for taller height limits at urban villages in key locations along Northbourne Avenue, including at Macarthur House".
Asked for the discussion paper, Mr Rake sent a document which mentions "taller" buildings in one diagram, but the diagram does not imply anything near as tall as 50 metres.
In March, the government released the boundaries of a new "urban renewal precinct", covering Northbourne Avenue and the city, which it has carved out for separate development, like Southbank in Brisbane and Barangaroo in Sydney. But to date, no special design guidelines or planning rules have been released for the precinct.
The call for tenders to demolish Macarthur House is the latest move in the sale of large blocks of land along Northbourne Avenue to generate revenue and patrons for the light rail project.
Macarthur House is to be replaced by as many as 530 apartments on Land Development Agency figures, but Cardno's estimate was a yield of 490 apartments, up to 16 storeys.
Macarthur House is still used by ACT public servants, including roads, capital works and procurement staff, but the tender documents say they would be gone by February 2018.
The demolition is time critical, according to the tender call, and must be completed by March 2019 so the block can be sold.
To date, three major blocks have been sold on Northbourne Avenue. "Dickson on Northbourne" sold a year ago to Johnny Roso, who promised a design competition for the replacement buildings. "Lyneham on Northbourne" sold to JW Land (parent of SHL), which is also developing the large former public housing block on the corner of Cooyong Street and Ainslie Avenue in the city. And the Dickson motor registry site sold to Doma.
Macarthur House is a seven-storey building with a two-storey wing, with Wattle Avenue, Lyneham, at the rear boundary.