Preserving history with talent, teamwork, and technology.

Overlooking Lake Sisseton in Fairmont, Minnesota, the Martin County Courthouse and a 108-foot tower with a copper dome serves as a historic landmark and image for Martin County and the surrounding community. Due to water infiltration and concerns with structural integrity, the County sought ISG to conduct a feasibility study to assess the existing conditions of the remarkable building. What started as a feasibility study, has become an extensive restoration project by teams at ISG and the County, and numerous restoration experts.

Built in 1907 and designed by Bell and Detweiler Architects, the three-story Beaux-Art style courthouse has a sandstone and limestone exterior, an arched entrance, and is topped with a 50-foot-tall copper dome. The dome rests upon a 58-foot structure with peaks, pillars, and arches that add to the architectural appeal. The dome features four, seven-foot-tall glass clockfaces and face dials and eagles with six-feet wingspans are perched on globes on corners of the dome. The impressive artistry flows from the exterior into the interior of the courthouse. Artist Franz Edward Rohrbeck furnished the underside of the dome with a massive six-piece mural representing the culture of law.

ISG, a nationally recognized architecture, engineering, environmental and planning firm in the Midwest, used technology and their experience assessing historic buildings to bring the Martin County Courthouse back to its original glory. Since its construction over a century ago, there have been minor improvements. The original plans of the building were available as a resource but offered little useful information to provide an accurate representation of the existing structure and building elements, such as wall dimensions, roof details, and the foundations supporting structure.

View from the Top

Compared to conventional measuring methods, such as measuring by hand and relying on 2-dimensional images, ISG’s survey team used a range of tools with the technological capabilities to gather data more efficiently, safely, and within a few millimeters of accuracy.

To generate a model of the interior and exterior of the courthouse, surveyors used a FARO Laser Focus3D x 130 terrestrial scanning system. This compact, tripod-mounted laser gathers thousands of pieces of data by emitting laser pulses onto an object using GPS and LIDAR—light detection and ranging—technology.

ISG gathered most of the measurements from the FARO Laser and used drone photogrammetry to fill in the intricate details of the dome and other building elements. A high-quality camera attached to a drone takes numerous pictures from a range of angles to combine them into a georeferenced, 3-dimensional model.

In this instance, the technical team used the technology to scan the building in its entirety and gather information from areas otherwise unreachable. The team could provide and present the designers with information as if they were standing 75’ above the clock tower themselves or within the walls of the dome.

Restoration Collaboration

The information gathered generated a set of existing drawings used for the assessment of the building’s condition. The assessment exposed the following needs:

  • Courthouse roof and parapets restoration to retain structural integrity
  • Replace courthouse roof—remove asphalt roofing and furring, apply ice and water shield, sheathing, and new copper roof with improved gutters and edges
  • Re-point the stone from the courthouse roof to the base of the copper dome
  • Copper dome replacement and restoration of intricate elements
  • Repair copper dome support structure and replace rusted members
  • Replicate four copper eagles from the two that remained
  • Four (4) clock faces and clock hand replacements
  • Clock mechanism restoration

Renaissance Roofing provided their copper workmanship and restoration expertise to refinish the roof and dome, and recreate four copper eagles from the two remaining copper eagles through an extensive, delicate process of creating 44 molds and five stamps of copper sheets.

Rory DeMasy, horologist from Mechanical Watch Supply in Minneapolis, recreated and refurbished the elements of the clock and the clock mechanism. To bring it back to original working condition, an automatic rewind device replaced the electric motor.

More to Come

The restoration of the exterior is nearing its completion. Currently, the roof is under construction and will soon showcase copper and new rooftop units.  Mural restoration may be decided at a later date given the necessary funding.

Bringing the courthouse back to life has been a group effort by these teams of experts. Through their dedication and expertise, the Martin County Courthouse will soon be revered by the community for many years to come.

Meet Bob Mickelson

With over 40 years of experience leading project management and construction administration for a wide variety of industry partners, Bob has a proven record of providing dependable and practical solutions...