IMEG provided structural engineering services for the Lone Rock Retreat in Bailey, CO. The retreat, a non-profit campus for teachers to learn new techniques, features a seven-acre village nestled into the hillside of a mountainous area. Amenities include three dining experiences, a lodge/seminar building, yoga and fitness rooms, 15 cabin buildings, 60 guest rooms, trails, and hot springs.

One challenge of the project related to the curved beams located on the lodge building. Due to the tight radius of the beams, to determine feasibility and constructability the team had to work closely with the glulam and steel suppliers for the appropriate materials and shape. The steel beams were created by welding laser-cut steel plates together to create the necessary shape. For the glulam members, the supplier had to utilize ½” laminations in lieu of the typical 1-1/2” laminations to make the radius work without creating stress fractures.

Rammed earth walls utilized heavily throughout the lodge building presented additional challenges. Since there is no building code that covers rammed earth, the team had to justify the design under ACI (concrete) code due to the inclusion of cement mix in the walls. This took additional time and resources. Another challenge concerned the thickness of the rammed earth walls (20+ inches) and their proper integration with the architectural layouts. This issue was resolved with a steel canopy and several large steel columns that would be hidden inside the walls to facilitate construction sequencing; this allowed the remainder of the structure to be erected prior to the installation of the curved rammed earth walls along the front of the building. The team also coordinated with the architect to allow the grand staircase handrails to be recessed into a rammed earth wall for a more unique look.

IMEG worked closely with the owner and other design team members for most of the design phase. Weekly meetings allowed each discipline to discuss design challenges and best solutions for the owner’s budget and desired aesthetics.