Big office towers face special challenges when temperatures drop and snow piles up.
This unusually frigid winter has resulted in many headaches, but keeping some of the Twin Cities’ biggest commercial buildings operating smoothly this season has proved especially daunting for property managers.
“It’s been a rough year, as bad as it’s ever been,” said Chuck Palm, senior vice president of Occupier and Investor Services for the Bloomington real estate firm Cushman & Wakefield/NorthMarq. Palm oversees engineering and maintenance for more than 400 properties, about 70 percent of them in Minnesota.
This winter was the ninth coldest on record in the Twin Cities, and the most frigid since 1979, with 50 days recording a temperature below zero. It also ranked as the fourth snowiest on record.
“It’s been a real treat, and I say that with love and affection,” said a wry Bill Thurmes, the property manager at US Bank Center in downtown St. Paul. “When it gets so bitter, bitter cold, it throws off the balance of a building.”
The “design temperature” for buildings in the Twin Cities is minus-11 degrees, said Larry Schoen, president of Schoen Engineering, a Maryland-based consulting firm. That means engineers design buildings here on the belief that it will be warmer than minus-11 99 percent of the time, he said. “You don’t design for the absolute worst temperatures,” he said. “There are limits to engineering.”
So when temperatures dip below that level for any length of time, as they have in Minnesota this winter, some serious issues may arise.
An obvious challenge is snow removal. Most property managers try to estimate the impending season’s snowfall and budget accordingly. But this year, “snow removal budgets were blown out,” Palm said.
“We do all our own snow removal, and we’ve been running our snow machines constantly,” said Mike Blomberg, operations manager for LaSalle Plaza in downtown Minneapolis. Once the city plows the streets, Blomberg’s crew must haul away that churned-up snowpack, as well. “Our snow budget was crushed this year,” he said, especially given the frequent mini snowfalls of an inch or two that still required attention.
Julie Bauch, general manager of 180 East Fifth, a 112-year-old office building in St. Paul, said snow around her building was piled in a nearby alley. The imposing mound began to melt this past weekend — and not a moment too soon. Finding a hauler to take the snow is not as easy as it sounds — since it may be contaminated with chemicals used to clear the sidewalks, she said. In addition, hauling snow off-site can be an expensive proposition.
Another challenge involves heating buildings in a uniform way, even when temperatures dip to or below zero for a sustained period. Corner offices are often among the chilliest, as well as perimeter areas. “It’s really hard to balance the heat in a building,” Thurmes said.
Generally, he said, he looks at the winter patterns for the past five seasons, comes up with an average and tries to adapt energy costs accordingly. He’ll even factor in predictions from the Farmer’s Almanac, but few could have predicted this year’s mix of intense cold and heavy snowfall.
The cold generally surrounds a building and seeps in wherever it can, Palm said. In those areas, sprinkler systems may freeze, causing water to build up in pipes, which burst as a result. “Then you have water flowing down stairwells,” he said.
Technology can help, Schoen said. Many newer buildings have web-based thermometers installed throughout, so property managers can keep track of temperatures. Some even have alarm features.
Still, “the new buildings are the ones that haven’t yet experienced cold winter, and that’s where I’m hearing of problems,” he said. “The advantage of older buildings is that they’ve been through the paces of extreme weather before.”
The relative thaw expected for this week only exacerbates the many challenges for these huge structures this season, including vast snow melt and prospective leaky roofs. “When you have a sudden thaw, the water has to go somewhere,” Palm said.
This is problematic because many commercial buildings have flat roofs. If there’s several feet of snow blocking a roof drain, water can’t get off the roof, “then you can have a swimming pool on the roof,” Palm said. In addition, pipes that drain water from roofs may freeze, so “water may find a way into the building.”
A Wal-Mart store in Forest Lake was evacuated on Sunday over concerns that snow on the roof might have caused structural damage, although the store reopened later Sunday evening.
Schoen, who serves as a consultant for the Building Owners and Managers Association International, wrote a book that deals in part with preparing for extreme temperatures and snow. The key is preparation, he said, noting “you have to think about heating in summer and cooling in winter.”