In below freezing temperatures on Thursday, construction workers labored atop WaHu, a student housing project. About a mile away, builders continued work on another massive student housing development, Radius @ 15th.

Developers and construction firms spend extra time and money to battle frigid temperatures each winter in order to meet their projects’ deadlines, and this year is no different.

Much of the exterior is already done on WaHu, which sits on the corner of Huron Boulevard Southeast and Washington Avenue Southeast. That means much of the remaining work on the building is happening on the inside, said developer and owner of CPM Companies Daniel Oberpriller.

But his contractors still have to make seasonal adjustments, he said.

To work with materials like sheet rock, which must be set at a certain temperature, they typically bring in heaters.

And to lay down concrete, Oberpriller said, builders pour cement made with heated water, then wrap it in plastic and use a heating device powered by propane or electricity to keep it above freezing while the cement sets.

He said that process is currently underway inside of WaHu.

To break ground in the winter, especially during colder months like January and February when the ground is often frozen solid, workers lay down a heated blanket for several days to thaw the soil.

Troy Wenck, president of Reuter Walton Commercial, worked with Oberpriller on the 700 on Washington apartment complex. He said winter is more of an inconvenience than a hindrance for construction.

During the cold season, time and money are allocated toward things like heated concrete, Wenck said, and tenting and heating targeted work areas where work is being done.

But one inevitable factor that tends to hold up a site’s progress is the slowed rate of labor.

Added clothing like overalls and gloves tend to hinder contractors, said Gary Skogman, yard manager for Kraus-Anderson, a Minneapolis-headquartered construction firm.

His construction company typically budgets between $50,000 and $500,000 for extra winter-related expenses when his firm breaks ground in cold weather, he said.

Reuter Walton budgets for about two weeks that are too cold for progress, Wenck said.

Those “lost days due to weather” depend on how much of the structure is finished, he said.

For example, Wenck said, if construction workers are working on a basement and therefore exposed to the wind and cold, the firm budgets for extra time.

At Kraus-Anderson, Skogman said, days off aren’t built into the plan, and construction workers don’t get paid for days they don’t work.

“Weather’s not scheduled in,” he said. “If you lose two days because of weather, you gotta make it up.”

Some construction firms hire unionized workers who negotiate beforehand at what temperatures they refuse to work, Oberpriller said.

That’s true for Mortenson Construction, the company behind the new Vikings stadium in downtown Minneapolis.

But the company pays more attention to individual stadium workers than the preset standards, said the firm’s vice president of operations, Kendall Griffith.

Even at hundreds of feet in the air, he said the stadium’s construction procedures are like those of any other large-scale projects.

“Certainly it’s harder to insulate something or heat something or cover something up that’s a hundred feet in the air than it is when it’s on the ground,” Griffith said, “but it’s all part of the process.”

There are no specialized winter employees, he said, because they’re doing normal construction work — only in freezing temperatures.

Though progress slows during the winter months, Skogman said, those who are willing to construct in winter do a remarkable job.

“It takes a strong work ethic to go out every day and put up with the cold weather conditions,” he said.