The region's industrial space vacancy rate ticked up 0.1 percentage points to 4.1 percent as 1.5 million square feet of speculative space came online, according to a new fourth-quarter report from Newmark Knight Frank.

The report also says that rents continue their upward trajectory, increasing to $5.99 per square foot in Q4 from $5.86 per square foot in Q3. They were $5.56 a year ago in metro Detroit's approximately 390 million-square-foot industrial market.

"The positive performance of newly completed speculative developments and continued groundbreaking for build-to-suit facilities are indicators that (the) Metro Detroit industrial market remains strong," the report says.

Industrial real estate for years has been considered one of the bright spots in Detroit area real estate as the auto industry's health has propelled business for manufacturers and others in the region.

"At this moment in time, occupancies remain incredibly strong and I don't see anything that would suggest things are about to change for the worse, other than it's lasted so long it's almost too good to be true," said Peter Burton, principal of Bingham Farms-based developer Burton-Katzman LLC. "All of our buildings are full and they rarely go empty, and if they do go empty, they fill up almost immediately."

The region's two largest industrial submarkets, Macomb County and southeast Oakland County, have vacancy rates of just 3 percent and 2.3 percent, respectively, according to the Newmark Knight Frank report.

Macomb County has 82.75 million square feet with rents of $5.28 per square foot for general industrial space, $6.47 per square foot for warehouse/distribution space and $7.19 per square foot for R&D/flex space. In southeast Oakland's 87.24 million square feet, general industrial is $5.87 per square foot, warehouse/distribution is $5.99 per square foot and R&D/flex is $9.03 per square foot.

The report says that 113 industrial projects totaling 18.5 million square feet have been completed in the last five years.