But, for now at least, it is a slow and careful process.

A series of test pits, between one and three metres deep, have been dug at the base of one of the site's heritage buildings, the Harris Terrace, to test its foundations ahead of protective braces being installed.

The pits would examine the bases of the buildings to determine how they were constructed and find out whether there had been any subsidence over the years.

Archeologists from property consultants Urbis have been finding some relics, including small bottles, in their test pits.

"We haven't come across too much yet because a lot of this area was modified for the construction of buildings in the '80s and '60s, but we have found a few small artifacts," archeologist Holly Maclean said.

Ms Maclean said Harris Terrace was constructed in 1865 to house parliamentarians, or other people associated with the Queensland Parliament at the end of George Street.

Destination Brisbane Consortium project director Simon Crooks said the 1860s-built Harris Terrace would serve as "the front door of the development", via retail outlets.

As such, Mr Crooks said Harris Terrace, along with the other heritage buildings at Queens Wharf and the Riverside Expressway, had vibration monitoring equipment installed.

"We're taking, to use the vernacular, a 'bolts and braces' approach," he said.

"We're assuming that there could be as much vibration as we could possibly assume and we're bracing them accordingly.

"We're not leaving them there, we're actually planning for the worst-case scenario."

Harris Terrace, as it appeared prior to development starting. Photo: Dylan Evans

Eventually, braces would be constructed around the Harris Terrace and other buildings to protect them as workers dig and drill 30 metres down, before building the development's signature high-rises.

"What we won't be doing is punching through walls," Mr Crooks said.

"We may remove some of the windows, putting structural steel on the outside and putting ties through.

"The windows will be stored, because it's all heritage, and sealed so we don't actually let any rain and debris in, because we've got to control the environment inside from a humidity viewpoint.

"It's effectively putting a straitjacket around the structures and that straitjacket will be informed by our footing investigations.

"We're not taking any risks on this, we're actually probably being over-conservative to be sure."

Harris Terrace (left) will be at the "front door" of the Queens Wharf complex. Photo: Destination Brisbane

Other heritage buildings on the site, which included the nearby Mansions, National Trust House, the Printery and the former Public Services Club, would also be similarly tested and excavated.

Mr Crooks said it was a small but important milestone in the project's construction.

"This is probably our first major step after handing over the main demolition contract to Probuild in what's going to be a five-year-plus project for us," he said.

Mr Crooks said, of all the heritage buildings on the Queens Wharf site, the Harris Terrace was probably in the worst shape, but even that was not too bad.

"I would suggest the movement cracking that's there isn't significant," he said.

"We're putting 21st century engineering techniques on something that was done in the 1800s, so we're probably applying a lot of rigour that wasn't there beforehand, looking at the ground material and seeing how it is.

"If we're not happy with how it is on current standards, we'll adjust it and fix it."

Queensland Public Works Minister Mick de Brenni said the preservation and reactivation of the heritage buildings was an important feature of the massive development, which he described as one of the biggest Brisbane had ever seen.

"I guess it shows the care that's being taken in this entire project, that we've got archeologists on site that are making sure that artifacts are taken care of and also, importantly, that this building will be a real feature of the entire precinct," he said.