The Canberra Times has obtained a list of 45 variations to the project.

It includes $7.7 million of extra costs, and nearly $600,000 of savings through revisions to the scope of the project.

The list, released in response to questions from November's annual reports hearings, showed an extra $3.9 million was approved to change the design of the light rail stops.

Early artist's impressions of the 13 light rail stops show a more basic design than the final stops, with a shape inspired by the undulation of the Brindabellas.

The final stops also include weather screens with design work from Canberra artist Hannah Quinlin.

An extra $5000 was also approved to pay Indigenous artist Uncle Jimmy for the design of the light rail seat covers.

Another $1.055 million was approved to change the street furniture in the light rail corridor "as per the territory direction".

About $2.1 million was approved for amendments to the "innovative design works".

A sum of $29,750 was also included for monthly drone flyovers to generate timelapse photography for "the purpose of project reporting".

Canberra Metro published one bird's eye view video on its website in January last year, while another filmed in August was released in September.

Its accompanying blurb said the footage showed the "great corridor" in a way only afforded to "perhaps a high-flying magpie or currawong" in the past.

"However, with state-of-the-art drone technology we can now imagine ourselves on their feathered shoulders," it reads.

On the flipside, $339,638 was saved by limiting of Canberra Metro's construction on Kate Crace Street to accommodate city services works. $219,180 was saved on the rationalisation of mid-block crossings.

Canberra Metro also saved $25,000 by removing the requirement for passengers information displays systems at intersection stops in Gungahlin, Dickson and at Alinga Street.

The contract originally stated the displays had to be provided at all stops and onboard all light rail vehicles.

Some variations also recorded no cost, such as changes to ensure new verge planting is consistent with current grass species.

The contract was also changed to allow for a gas-tensioning system, rather than the auto-tensioning system that was previously required.

A variation to include the recording of social media comments also attracted no extra cost.

The construction of light rail stage one is budgeted at $707 million although the total cost including operations is $939 million.

Under Treasurer David Nicol told last year's annual reports hearings there had been a number of changes to the scope of the project since contracts were signed in 2016.

"Not a significant number, but a number," Mr Nicol said.

Mr Coe then asked whether there were any unresolved contract variations that threatened to have an impact on the cost of the project.

"That will depend on how they’re resolved but there could be sums of money involved, yes," Mr Nicol said.

However a government spokeswoman said at the time variations that have been approved over the last two years have largely cancelled each other out, and the territory was yet to pay any of the $117 million contingency to Canberra Metro.

The territory is also expected to save money due to the delayed start of light rail.

The consortium was scheduled to complete construction on December 21 but that has been pushed back to an undetermined date in early 2019.

That will mean Canberra Metro will lose out on availability payments, ranging between $2.8 million and $4.7 million a month, until the project is finished. That money will be counted as savings by the territory.

Asked what those expected savings are during the hearings, the government said: "The government will make publicly available information on any change in payments under the Public Private Partnership contract with Canberra Metro."

It can also be revealed ACT taxpayers will save at least $10 million on the courts project, which is running nearly a year behind schedule.

Answers to a separate question on notice show that while about $1 million of extra variations have been approved, those costs will be covered from future savings from delayed payments under the public-private partnership contract.

Availability payments will not start until the final stage of the project is completed next September.

"Due to the delays in construction the [net present cost] of the future payments due to be made by the territory will reduce in comparison to the $250.4 million initially expected," the government said.

"This reduction will be in excess of $10 million but is not able to be calculated accurately until after both stages have been completed. In summary, the overall cost of the public private partnership contract to the territory is expected to be reduced as a result of the delays, even after accounting for the increased appropriation noted above and the impact of variations."