Squeaking tennis shoes. The rise and fall of voices in unison with the ebb and flow of a basketball game. The smell of sweat. The brisk bark of a whistle. Rays of sunlight washing over the hardwood. All of these have contributed to the fond memories alumni have of the “Old North” gymnasium at Carroll College in Helena, MT. The 1917 structure, set on the north side of St. Charles Hall, has stood the test of time and holds mastery over one of the most noble of sustainable design strategies: architecture that is loved and will be cared for, from one generation to the next.

For a building to maintain its vitality over time, often a change of purpose is required. In recent years, the old gym was used as the campus theater, its vitality lying dormant for years, waiting for a new vision. CTA is now helping Carroll breathe new life into the tired walls to create a much needed chapel for the Diocesan College.  Change, however, often involves overcoming past attitudes.

More than any other building type throughout history, connotations surrounding chapels and churches have revolved around shape and proportion. The evolution of Christian church forms, from the organization and formality of the Roman basilica, to the cruciform plan and arched openings of European cathedrals, to Gothic revival structures in early American history — like the Helena Cathedral — has contributed to powerful expectations of what a chapel should (and should not) be. Similarly, how could patrons possibly accept that “Old North” could ever be anything other than a gymnasium?

The truss design is governed by intrinsic geometry of two intersecting circles with center points sharing common positions on each other’s edges. These circles represent Heaven and earth coming together with the intersecting region, known as the vesica piscis, framing the position of the crucifix above the altar.

The trusses posed some special design challenges to CTA structural engineer Pete Jacobsen. The simplicity of the resultant forms do not reveal the complexity required to create them. In extreme wind or seismic events, the compression forces of the bottom chord needed to resolve through the curved steel web members to allow the center rod to remain visually minimal. In addition to aesthetics, constructability frequently governs the design of exposed structural elements. The fabrication process drove the size of the steel members and added additional strength and stiffness to the system, beyond what was necessary for purely structural requirements.

All of the new design elements work in unison to create a new identity for “Old North.” The chapel is currently under renovation by Dick Anderson Construction and is scheduled to be dedicated Nov. 1, 2017 — All Saints Day.