Could You Build the Loretto Staircase Today?
Nothing about the Loretto staircase is beyond a modern shop. A competent stair builder today could model the double helix in CAD, cut the curved stringer segments on a CNC router, and stand a working copy in a matter of weeks.
The useful question isn’t whether we could rebuild it — it’s what trying would teach us about how hard the original actually was.
What a modern build would take
The structure is well understood. A spiral with no central column carries its load through two helical beams — the stringers — anchored at the floor and the loft, the inner one wound tight enough to act almost like a hidden pole. (The mechanics are on our how it works page.)
A contemporary engineer would model that as a helical beam, run the loads, and specify curved laminated stringers — thin layers of wood glued and bent to the exact helix, a standard technique for curved stair work.
CAD fixes every dimension; a CNC cuts the segments and their bevels to a fraction of a millimetre. None of it is exotic.
The part that stays hard
Strip away the machines and the difficulty reappears, all of it in the layout. The original builder had to develop the helix — unroll a climbing, curving beam into a flat full-size pattern — and mark every segment, angle, and peg hole by hand so the pieces met without gaps.
That is the French carpentry craft called the trait de charpente, covered on our trait method page, and it’s the skill a CNC quietly replaces. A modern replica doesn’t reproduce the feat so much as route around it.
The carpenters who look closely tend to land in the same place. Tim Carter, writing as a master carpenter in the Washington Post, put it plainly: building a stair like this with modern tools “would be a feat,” and doing it “with crude hand tools, no electricity and minimal resources” is “mind-boggling.” The awe is not at the physics; it is at the hands.
What a replica would, and wouldn’t, prove
A faithful build would settle one thing cleanly: that the staircase obeys ordinary structural mechanics, with no hidden trick beyond a very tight inner stringer and good joinery. That’s the same conclusion Joe Nickell reached by inspection (see debunked-or-miracle).
What it could not reproduce is the original constraint — hand tools, no power, no CAD, a lone craftsman — which is the only part the legend ever really turned on. Prove the structure all you like; the human achievement sits in conditions a modern shop can’t recreate even if it wanted to.
The honest takeaway
“Could you build it today?” has an easy yes and a more interesting tail. The easy yes deflates the “no one could replicate it” framing.
The tail is the part worth keeping: the closer you look at how a modern shop would do it, the clearer it becomes that the original builder did, by eye and by hand, the one step we now hand to a machine.
Keep exploring
- How the staircase works (the structure to replicate)
- The trait method (the hand layout a CNC replaces)
- Debunked or miracle? Every claim vs the evidence
- Back to the Loretto Chapel staircase overview
Researched & fact-checked by the Loretto Volunteers Editorial Team
Loretto Volunteers is an independent research project documenting the history, architecture, and enduring mystery of the Loretto Chapel staircase. We work from primary and archival sources and show our evidence. Last reviewed: June 2026.