Built of stone and light

Grotesque faces, fantastic winged dragons, and visibly intoxicated wine swillers — a whole range of profane characters from 1469 is carved into the oak choir stalls of the Ulm church. These decorations adorn the small shelves called “misericords” under the stalls’ folding seats, which churchgoers could lean against with a modicum of comfort while standing during a service.

"Misericordia" is the Latin word for compassion or mercy, and the Gothic church, which was built between 1377 and 1890 and boasts the world’s highest church tower at 161.53 meters, certainly needs some compassionate attention today. “If there weren’t any construction workers here, I’d have serious cause for concern,” says the minster’s master builder, Ingrid Helm-Rommel, who is in charge of the upkeep of the building’s interior and exterior.

When Helm-Rommel, a trained draftswoman who holds a doctorate in architecture, talks about her job, the listener can clearly grasp not only her mastery of materials such as stone, wood, iron, lead, and glass, but also her pride in being part of an honorable tradition. Asked which historical master builder she would have liked to meet, she says: “I would have loved to talk to Ulrich Ensinger, who headed the construction work from 1392 on.”

She goes on to paint a colorful picture of the medieval construction site, with different craftsmen working together to form a microcosm of their own, in which trades were often passed down within families from one generation to the next. “The stonemasons, for example, had their own hierarchy. At the bottom were those who hewed rough stones and on top were the skilled sculptors,” she says.

The church was built using a variety of different materials: limestone from the nearby quarries, sandstone from the borders of the Swabian mountains, shell limestone, and thousands of hand-molded bricks, sintered to a shiny and almost dark-red sheen. These are materials that have withstood the passage of time over centuries, yet are now being increasingly damaged by heavy rainfall, acid rain, and frost wedging, which is caused by the alternate freezing and thawing of water during the long weeks of winter.

The inventory of some of the damage sounds like a medical file: alveoli formation (blistering), sanding, crumbling, disintegration, mineral accretion, and saline bloom are only a few of the symptoms that call for active sympathy with the building. “For us, the preservation of the stones is of primary importance,” says Ingrid Helm-Rommel. First, the condition of the stones is documented with the aid of digital photogrammetry, then the various types of stone and their condition are mapped onto a chart.

The results are collated into a precise overview that looks like a puzzle consisting of different colors. The next step is planning: What problems are the most pressing? What needs to be cleaned or desalinated so the stone won’t be further damaged from the outside? What needs to be replaced, and how?

In addition, considerable funds need to be raised. EUR 10 million was the price tag for the 11-year renovation of the southern choir tower alone. The state's chief conservator Michael Goer has praised the renovation for “taking the requirements of monument conservation into account in an exemplary way.” The church is regularly monitored by stonemasons who have been trained as industrial climbers.