Civil Engineering Magazine: Minnesota State Capitol Restored and Revived

A restoration returned the Minnesota State Capitol to its historic stature while updating architectural and engineering systems for 21st-century functions.

Minnesota State Capital, Campus Renovation

Weaving state-of-the-art technology into a 1905 building while preserving the historic fabric required innovation and cross-disciplinary thinking from the entire team.

The five-year-long historic restoration of the Minnesota State Capitol created a community amenity that feels virtually brand new—yet retains the architectural splendor of an earlier era. The project, spearheaded by multidisciplinary architecture and engineering firm HGA, of Minneapolis, touched virtually every aspect of the capitol, from inside to outside, dome to basement.

The 1905 structure was designed by architect Cass Gilbert, who was inspired by the Beaux-Arts style of architecture displayed at the 1893 World’s Columbian Exposition in Chicago and who would later go on to design the United States Supreme Court Building. Gilbert’s design featured an exterior of white Georgia marble and St. Cloud granite and a three-level dome inspired by Michelangelo’s Basilica of St. Peter in Vatican City. It was listed on the National Register of Historic Places in 1972.

Existing Conditions

With its prominent location on the Capitol Mall, surrounded by other government buildings, monuments, and memorials, the Minnesota State Capitol is one of the most visible and identifiable buildings in downtown St. Paul and the pride of the Twin Cities. A public landmark that attracts thousands of visitors annually, the grand structure is also a working building, housing chambers for the Minnesota Senate and House of Representatives, the Minnesota Supreme Court, the office of the state attorney general, the office of the governor, and private legislative offices.

By the 21st century, the structure had reached a critical point of deterioration, including areas of crumbling exterior marble; antiquated mechanical, electrical, and plumbing (MEP) systems; inadequate life-safety systems; insufficient public areas; and water-damaged and deteriorating decorative paint and murals throughout the interior.

Although small renovation projects had been undertaken throughout the building’s century of use, they were done in piecemeal fashion with limited budgets and timelines—resulting in varying levels of work quality, styles, and regard for historic character. The infrastructure had been patched and repaired time and again, essentially masking the issues with bandages. Parts of the electrical and mechanical systems were still original from 1905 and were badly deteriorated, inefficient, and difficult to maintain. The exterior of the building was no better off, with a leaking roof and large pieces of stone in danger of falling off the facade.

Minnesota state capitol renovation and restoration interior

Comprehensive Renovation

A significant political push for a comprehensive renovation project began in 2007, and this concept envisioned a large underground addition under the Capitol Mall to accommodate infrastructure and increase workspace. The plan proved contentious and the project was not funded, but funding was set aside for additional study and asset preservation, and a deeper analysis of how to solve the structure’s problems began.

The next major push for renovation began in 2012. This time the scope of the project was determined via 11 workshops that were open to all stakeholders, including legislators, the governor’s office, the press, the Minnesota Historical Society (MHS), and lobbyists. When the workshops were complete, three goals for the restoration project had been established. The first was to improve functionality to ensure the capitol would effectively serve its current government functions and continue to do so for the next 100 years. The second was to ensure that the building would be safe and accessible, which would be accomplished by upgrading life-safety systems, providing secure mechanical systems and infrastructure, and complying with guidelines for universal accessibility. The third was to preserve and restore the architectural integrity of the structure and the essential design elements related to interior details and exterior stone.

Team Coordination

HGA had been involved in the structure’s renovations and various studies for nearly 10 years and proved a natural fit to lead the full restoration. Although the Minnesota Department of Administration’s Real Estate and Construction Services was the primary client overseeing the project, the restoration involved many additional design partners, including architects, engineers, commissioning professionals, interior designers, technologists, landscape architects, lighting designers, planners, sustainability experts, workplace strategists, preservationists, historians, artists, and craftspeople.

Valuable insight was provided by the client, strongly invested public agencies, and special interest groups, including the MHS, the Minnesota Department of Labor and Industry, the Minnesota Department of Human Rights, the St. Paul Building Trades Council, the Capitol Area Architectural and Planning Board, the State Capitol Preservation Commission, the Cass Gilbert Society, the Minnesota State Historic Preservation Office, the Minnesota House of Representatives, the Minnesota Senate, the Minnesota Supreme Court, the Minnesota Office of the Attorney General, the Minnesota Department of Public Safety, and the Minnesota Office of the Governor.

Prioritizing Goals

To systematically prioritize the project’s goals, the design team identified four historic zones within the capitol to determine where infrastructure could be safely inserted with minimal disturbance to the architecture:

  1. Zone one included areas with historic stone, artwork, and/or ornate decorative painting. This was the highest level of preservation and was to remain undisturbed.
  2. Zone two included areas with historic character for which a combination of preservation and restoration would be needed.
  3. Zone three included previously re-modeled areas, such as offices, that exhibited little evidence of historic or character-defining features.
  4. Zone four encompassed areas that had not been previously occupied and could be renovated as needed to meet the engineering requirements. Zone four spaces included parts of the basement as well as the mechanical/electrical rooms.
Read More . . .

To learn more about how the multidisciplinary team of architects, engineers, and consultants collaborated to restore the Minnesota State Capitol, visit Civil Engineering Magazine.

About the Authors

Deb Young, AIA, is a Senior Project Manager.

Sarah Berseth, PE, is a Mechanical Engineer.

Sean Cotton, PE, M.ASCE, is a Structural Engineer.