In addition to the Monroe Blocks project — which is slated to feature a 35-story office tower and 482 residential units, including a 17-story residential tower, plus retail and other uses in a total of 1.4 million square feet across a series of buildings — Gilbert's team is building the J.L. Hudson's department store site project, redeveloping the long-vacant Book Tower and Book Building and constructing the new addition to One Campus Martius.

In the statement, Emerson said exterior renovation on the Book Tower project ($311 million) is "nearly complete" and that "the architectural and construction drawings are well underway as we prepare the interior for the next phase of the renovation."

In addition, the One Campus Martius addition ($95 million) is "ahead of schedule" with an expected 2020 completion. He said it is "nearly 100 percent pre-leased," but did not respond when asked who the tenant or tenants are.

Since publicly confirming a planned increase in height of the Hudson's site tower to the north of OCM to a possible 912 feet in September, Bedrock has been working on a redesign, multiple sources have said the last several months. At the time, Bedrock was anticipated to make a final height determination by the end of January, although one has not yet been made.

The sources said the redesign process has caused some delays in the construction.

It was the third time the publicly revealed tower height has changed since it was originally revealed in February 2017, when it was 734 feet tall, just 7 feet taller than the 727-foot Detroit Marriott at the Renaissance Center with a cost of $775 million.

Then in September 2017, another 66 feet and a sky deck were added to the building, bringing it to 800 feet in height and a $909 million price tag. The current price tag is not known, although data from Rockland, Mass.-based RSMeans shows that construction costs increase about 2.2 percent per year. Similarly, construction cost data from Marshall & Swift Valuation Service shows that in 2016, the cost to build a mixed-use building in Detroit was $275 per square foot, and for 2019, it's $302 per square foot, or an increase of 9.82 percent.

Overall, the Hudson's project was expected to include 103,000 square feet of retail and restaurant space; 168,000 square feet of event and conference space; 263,000 square feet of office space; 93,000 square feet of exhibit space; and 330 residential units in the tower. A 700-space underground parking deck and a public observation deck atop the tower are also planned.

Emerson said "complex foundation work has been in progress and will continue."

"The structure will begin rising above grade once the complicated foundation work is completed."

All told, those projects are publicly pegged at $2.14 billion, after receiving $618.1 million in tax incentives last year through a new program generally referred to as "transformational brownfield."

Otie McKinley, media and communications manager for the Michigan Economic Development Corp., which oversees the transformational brownfield incentives, said in an email last week that some of the tax reimbursement would be diminished if the developments aren't completed within five years of the award in May 2018.