Change seems to be a constant at Charleston International Airport.

People coming and going. Construction altering the landscape. The cost rising to build a better terminal.

For months, the price to expand and renovate the nearly 30-year-old building has been reported at $189 million. But that's changed.

First, Delaware North, which won the 10-year contract to supply restaurant service at the airport, and Hudson News, which regained a decade-long agreement to provide retail outlets, will together invest about $10 million to upfit spaces being provided through the Charleston County Aviation Authority's redevelopment. Second, about $1.85 million of an $11.2 million pot of money set aside for contingency expenses on the project has been spent through change orders. Some of that is the result of trimming the project back on the front end last summer down to what was believed a reasonable price before going into long-term debt through a bond issue.

The biggest part of the cost overruns - $670,000 - is the unexpected discovery of asbestos in a tar-like, waterproofing substance found inside masonry on the building's exterior walls. It's been there since the terminal was constructed in the early 1980s.

So far, that puts the project's price tag at just over $200 million. It's likely to go a bit higher before the last swipe of paint is put on the structure next year because construction is only 30 percent completed, says Matt McCoy with Baker Inc., program manager hired to oversee the project.

The good news is construction overruns are well under where they were projected with nearly a third of the work completed, but there are still walls to be chiseled away as crews remake the aging structure where nearly 3 million passengers are expected to pass through next year.

The rental car pavilion, except for some cosmetic changes, is completed and open. The central energy plant that will power the terminal has been topped out. Some of the area torn up for underground utilities has been reclaimed, much to the delight of airlines and baggage handlers. Structural steel for the extension of Concourse B, where five new gates are being added, is in place.

The new area for consolidated security and administrative offices is rising behind the airline ticket counters. The front canopy continues to be dismantled. It will be replaced with a more aesthetic look. The front brick walls are coming down to make way for glass to allow more lighting into the building. The new dome over the central hall will start taking shape this summer. The third baggage carousel is complete, and now each one will be closed temporarily as the ceiling is raised throughout the terminal.

Completion is now set for September 2015.

Reach Warren L. Wise at 937-5524.