Construction of five-storey car park next to John Gorton Building expected to begin March 2023

The project, to be built next to the John Gorton Building, will provide 1153 car spaces and include a childcare centre with capacity for 170 children on the ground level.

The infrastructure will support the future construction of a more than $1 billion national security precinct, quietly announced in the Albanese government's first federal budget in October.

The new National Security Office Precinct will inject a further 5000 staff into the parliamentary zone once built on State Circle, next to York Park.

Construction should commence in 2025, following completion of the car park.

Plans for the project have been referred to the department for approval, because of its potential to impact the environment of Commonwealth Land.

While the car park is unlikely to have a significant impact on threatened species and ecological communities, the Department of Finance reported it will significantly alter "the fabric and landscape of the parliamentary zone and the heritage values associated with Kings Avenue".

It will reconfigure roads in a way that changes the symmetry of the parliamentary zone, and, as a result, the road layout near the John Gorton Building will no longer match that near the Treasury Building.

The cul-de-sac between the John Gorton Building and existing 275-space car park, Dorothy Tangney Place, would be removed entirely, while traffic lights will be installed at the intersection of Kings Avenue and Blackall Street.

"Despite [mitigating] measures, there would remain unavoidable impacts to heritage values related to potential to impact upon heritage values of the Parliamentary Zone," the referral states.

A heritage impact assessment conducted by GML Heritage recommended further measures to reduce the impact, such as changing the building materials (a combination of pre-cast concrete and COR-TEN) to suit other buildings in the zone, which are generally constructed with light concrete, stone or rendered masonry.

The contractor also recommended reducing the height of the car park to prevent it detracting from government buildings in the area.

READ MORE:

If the project is greenlit by the federal environment department, a works approval can be submitted to the National Capital Authority.

The finance department expects construction of the car park to begin in March 2023 and be completed by September 2024. They will engage a contractor in January 2023.

The finance department also revealed it had considered five alternative locations in detail, but judged the final location as the best fit because of its ability to fulfil the National Capital Plan, provide Commonwealth-managed land in the parliamentary triangle, and provide efficient traffic pathways.

They investigated whether the car park could be built on the existing ground car park to the south of the John Gorton Building, but the impacts to the view of the heritage facade and the sightlines from Old Parliament House were judged to be too great.

That plan could also have impacted on the sub-surface communication room within the John Gorton Building.

Taking no action was not considered viable, as it would result in a net loss of car parking in the local area in the long term.

The Department of Finance's submission is open for public consultation until December 22, more information is available here.

We've made it a whole lot easier for you to have your say. Our new comment platform requires only one log-in to access articles and to join the discussion on The Canberra Times website. Find out how to register so you can enjoy civil, friendly and engaging discussions. See our moderation policy here.