The ASIO building on Parkes Way.

The ASIO building on Parkes Way. Photo: Graham Tidy

Six months after former prime minister Kevin Rudd opened ASIO's new headquarters, the intelligence agency is yet to occupy the $700 million Parkes building.

A high chain-wire fence capped with up to seven strands of barbed wire surround the building, described years ago by Parliament House's architect, Romaldo Giurgola, as a monster.

The five-storey building with an enormous glass facade was opened in July 2012 when a revised completion date was given of September last year.

The ASIO building on Parkes Way.

The ASIO building on Parkes Way. Photo: Graham Tidy

On Monday ASIO said in a statement the barbed-wire fence would come down when the agency took possession of the building.

No time frame for occupation was specified.

''The Ben Chifley Building is a special purpose, high-security building, designed with the capacity and flexibility to meet national security needs now and in the future,'' a spokesman said.

''The building has been a particularly complex and challenging project given the specific purpose and high-security requirements.

A group of unit owners near Lake Burley Griffin discussing building issues last year were told that one of the worst examples of basement flooding was on the site of the ASIO project, shortly before it was formally opened.

But the Department of Finance, which is responsible for the project, ruled out flooding as a cause for the delay.

''The delay is primarily attributable to the complex security and commissioning requirements of the building. There has been no

major flooding of the building,'' a spokeswoman said.

Planning documents show car parking was to be two to three levels below the natural ground level of the site.

Geotechnical studies found the groundwater table would likely be six metres to 15 metres below the ground surface, depending on the position within the site, which is about 200 metres from Lake Burley Griffin.

On Monday the seven-hectare construction site appeared to be empty except for a couple of men in bright yellow jackets and safety helmets.

Concrete barriers block the underground car park for 825 vehicles. Landscaping throughout the site appears to be completed.

Total car park accommodation is for 1100 cars.

Federal member for Fraser Dr Andrew Leigh said the perimeter fence was an eyesore.

''I hope the government will be able to find a permanent solution that meets the necessary requirements and is a little more visually appealing for residents and tourists,'' Dr Leigh said.

Federal and ACT politicians have long promised turning Constitution Avenue into a grand boulevard.

Over-planting of oak trees outside the new headquarters indicate the grand avenue concept was conceived many years ago. Three lines of mature oak trees are awaiting to be thinned out.

The National Capital Authority had planned to thin and transplant the surplus oak trees into an island separating duplicated lanes of traffic, before funding was withdrawn.

The ACT government has since taken over the grand boulevard project, and $42 million in Commonwealth funding was redirected to the territory to mark its centenary.

Meanwhile, on the other side of Constitution Avenue, the ACT Land Development Agency has resumed earthworks on Campbell Section 5, a mixed-use development that will include 520 residential units.