May 28, 2021

truss-construction.jpgHandshouse Studio students replicating a truss in Sanock, Poland.

This July, a full-scale truss — approximately 45 feet wide and 35 feet tall, or more than three stories — will be built outdoors in a 10-day workshop at The Catholic University of America on the campus’s University Mall, and will be available for public viewing. The Notre Dame de Paris Truss Project is organized by Handshouse Studio, which is setting up education workshops in Washington, D.C., to reconstruct one of the oldest trusses that once held the roof of Notre Dame de Paris. 

The truss will then be hand-raised and displayed in three events.

  • The first week of August, the truss will be hand-raised on the University Mall next to the Basilica of the National Shrine of the Immaculate Conception.
  • In coordination with the Historic Preservation Training Center of the National Park Service and with the support of Preservation Maryland, the truss will be hand-raised again during a one-day event on the National Mall.
  • In partnership with the National Building Museum, the full-scale truss will be installed in the building’s historic Great Hall for an exhibition. 

"We study architectural history through drawings, photographs, and on-site observations, but to study an important work of architecture by reconstructing it dramatically expands one's appreciation for the building and the people who created it,” says Mark Ferguson, dean of Catholic University’s School of Architecture and Planning. “Truss #6 will bring people together from all walks of life to experience the joy and hard work of crafting a beautiful building.”

The truss being constructedUsing the methods and materials of the original medieval builders, a team of traditional timber framers, carpenters, faculty, and students from around the United States will participate in the full-scale reconstruction of Truss #6, one of the original trusses that stood above the choir. With the support of Charpentiers sans Frontière, fellow traditional carpenters in France, Handhouse will use the official drawings created by French lead architects Rémi Fromont and Cédric Trentesaux of the Notre Dame de Paris reconstruction process. In the 2019 fire, the entire medieval wooden roof structure known as La Forêt, the forest, made up of more than 1,300 oak trees, was completely destroyed. 

“After watching the devastating images of the fire, it brings me joy that our university can contribute to the rebuilding of this beautiful church, which is an expression of love to our Blessed Mother,” says University Provost Aaron Dominguez.

“The loss of the roof during the 2019 fire at Notre Dame was devastating, complete, and more than simply material,” says Tonya Ohnstad, associate dean of graduate studies and instructor of a summer course on historic building methods that will take place in conjunction with the workshop. “It destroyed a forest of trees, generations of building technology, and an unimaginable amount of human spirit and energy embodied in the timber structure. What an incredible opportunity to be able to be part of the reconstruction, demonstration, and passing on of tectonic knowledge.”

Architecture Course Studies the process

In coordination with this project, Ohnstad will lead a course in Catholic University’s School of Architecture and Planning. Students will investigate the architecture and building methods of the French Gothic church as well as general medieval timber framing techniques. Students will produce posters illustrating the complete story of the socio-cultural-tectonic history of Notre Dame de Paris and its reconstruction, and will build a 1:10 scale model of the trusses over the church’s choir. Students will focus on joinery techniques and produce a series of models exploring details of the timber truss construction in Notre Dame de Paris using drawings from the French and calling on experts in the field.

The course will be supported by experts in medieval history, construction, and timber fields. The course will explore French protocol passed down from the Middle Ages for timber harvesting, fabricating, assembly, tools, and raising techniques. 

Class members will work alongside the traditional carpenters on the University Mall to hew and cut 17 white oak logs, some of which are more than 46 feet long, into the structural timbers. The course is open to all CatholicU and consortium students for credit, and can also be attended by non-degree seeking alumni and other interested persons.

“We believe collaboration is intrinsic to the effort to revive the Notre Dame de Paris’s iconic edifice,” Handhouse stated in their release. “We feel that the true value of this process is the embodied energy created by the thought, care, skill, and learning that comes from rebuilding objects as they were originally made. This effort will be a gesture of global solidarity honoring the importance of cultural heritage. We wish to share our Truss #6 reconstruction as a gift to France and the collective effort to rebuild Notre Dame de Paris as it was originally made.” 

Notre Dame de Paris, a UNESCO World Heritage Site, was completed around 1260. The rib vault roof structure and flying buttresses were introduced at this time and were considered one of the finest examples of French Gothic architecture. La Forêt, the timber roof structure assembled from 1,300 oak trees, was believed to have contained some of the oldest wooden frames in Paris.

To learn more about how to be involved in or support this project, visit For more information on enrolling in the architecture course at Catholic University, visit or email

Logo for the project