Climb Chicago’s Tallest Towers With The Architects, Engineers And Inspectors That Keep Them Safe
The team at Klein & Hoffman have climbed inside building spires, watched peregrine falcons swoop from the John Hancock Center and stood underneath Ceres, the art deco statue adorning the top of the Chicago Board of Trade Building — all in a day’s work for engineers during inspection season.
The members of Klein & Hoffman, a Chicago-based architectural and structural engineering firm, are gearing up for their busiest stretch of the year. Nov. 1 is the 2020 deadline for Chicago buildings that need ongoing "short form" inspections for their facades, while Dec. 1 is the deadline for buildings that require the more in-depth "long form" inspections.
As facade experts, the K&H team is responsible for making sure the outer walls of Chicago’s buildings are sturdy, intact and pose no threat to pedestrians below. But facades aren’t the only part of the buildings that need inspecting. From examining roof anchors that hold window cleaning crews aloft to measuring energy use and green building performance, inspections are a wide-ranging and crucial part of maintaining the city’s new and historic buildings alike.
Read on to climb up Chicago’s tallest buildings with the team that keeps them in tip-top shape.
Scaling The Walls
Since 2007, Chicago buildings have been under strict facade inspection guidelines — every two years, buildings over 80 feet need to have their facades inspected by a licensed architect or engineer. According to Rhocel Bon, a Klein & Hoffman senior associate, the process may involve an access contractor attaching a swing stage from the top of the building so that Klein & Hoffman can scour the building’s walls for signs of distress or weakening. The Klein & Hoffman teams also use emerging technology to complement the up-close inspections from swing-stage scaffolds.
“We’ve been implementing the use of drones to get a closer look at buildings than we could get from the ground,” Bon said. “For brick masonry and concrete, it’s not difficult to spot problems from the ground or with a drone, but for terra cotta, it definitely helps to be up close to understand what’s happening with the supports, which are often behind the walls.”
Bon recalled one inspection in which a drone flight revealed that a former contractor had never completed the tuckpointing of brickwork that it had been paid for years earlier.
But the work doesn’t stop on the walls. Fire escapes, flagpoles and railings need to be inspected every five years, as do the metal balconies that are common sights on renovated industrial buildings in Fulton Market and the West Loop. Klein & Hoffman associate Kathleen Strnad said she and her team will climb up and down 30-flight fire escapes, keeping a watchful eye out for rusting anchor points and stair treads that are detached or on their last legs.
“Our biggest strength is the depth of our expertise with all types of facades from historic terra cotta to brand-new glass curtain wall,” said Allison McSherry, an associate at Klein & Hoffman. “We have the engineering expertise to know when it’s done properly and when something is out of place.”
McSherry is interested in walls and windows for a different reason — their energy performance. It is part of her job to ensure buildings are compliant with the Chicago Energy Benchmarking Ordinance.
“Each building gets a plaque with its energy rating that it must display in its lobby,” she said. “The goal is transparency, and for the public to be able to see very clearly which buildings are the most efficient.”
Up On The Roof
Some of the most critical pieces of a building inspection happen on the roof. Roof anchors, metal posts that are embedded into the top of a building, help hold up the daring window cleaners and other facade maintenance equipment. Since 2017, the Occupational and Safety Health Administration has required building owners to have their roof anchors load tested and inspected before even hiring a window cleaning company, which has led to a flurry of requests for the Klein & Hoffman team to inspect roof anchors, said Terry McDonald, an associate principal.
Disused water tanks, many of which now sit empty, are another target for inspections. McDonald’s team ensures that wood tanks and steel support frames are sound. In 2013, an old water tank fell eight stories from the roof of a historic building in Lakeview and the ensuing flood of water injured three people. The accident has spurred the city’s attention for owners to ensure the venerable structures are safe, McDonald said.
“The absolute last thing an owner wants is an accident like that to happen on their watch,” he said. “When we find an issue that needs attention, we work with owners to make sure it can be solved efficiently and effectively to keep the public safe.”
As one of the premier structural engineering firms in the Midwest, the Klein & Hoffman team gets to inspect its fair share of unique Chicago structures, from rooftop statues to antennas that stretch hundreds of feet above the rooftops. Bon described standing in a scaffold, watching fighter jets fly overhead in preparation for the yearly Chicago Air and Water show.
“People pay a lot of money to go to the observatories at the tops of these towers,” he said. “But the views we get during these inspections are even more unreal.”
This feature was produced in collaboration between the Bisnow Branded Content Studio and Klein & Hoffman. Bisnow news staff was not involved in the production of this content.