THE Northumberland Hotel council office project has already become one of the Gympie Regional Council's most contentious financial issues.
And a report on the project's "whole of life cost" has not made the problem go away.
The report was presented to this week's Gympie Regional Council meeting by engineering director Bob Fredman, who told the meeting he had engaged consultants Rider Levett Bucknall to assess the project's costs over a lifetime of 50 years.
"Hopefully, it will give the council the information it needs," he said.
Acting Mayor Tony Perrett described the report as "fairly comprehensive", a comment endorsed by CrJulie Walker.
But this assessment was disputed by Cr Ian Petersen, who had successfully moved for the report to compare the costs of building new office accommodation with the cost of renting.
He described the report as "slanted" towards pre-existing council intentions to build its own office block on the former Northumberland Hotel site in Nash St.
"It says it does not consider the cost of finance or the return from any potential sale value of the land and building, and I would have thought those were major factors in assessing the cost," he said.
However, the consultant said the report also did not consider pro-construction considerations, including the efficiency benefits of having council staff under one roof.
The project would extend the existing Northumberland building to accommodate the council's design and water branches, currently in separate rented and "unsuitable" accommodation.
It would bring together "several related disciplines, that is design, planning, water strategy, development assessment and geographic information systems."
These disciplines "often operate in the same field and can obtain real benefits from synergies," the report said. It referred to an earlier report, by C Change Sustainable Solutions prepared in May, 2013.
This report recommended "departments be brought together to benefit from the efficiency gains that can be realised through increased cohesion.
"These gains could offset a significant portion of the annual cost of a new single building," it said.