Reinforcement For Archicad 19 — Eptar

Not a chaotic mess of red lines, but a perfect, adaptive lattice. The bottom rebar followed the tension curve like muscle fibers. The top rebar compressed along the arch’s spine. Where the twist happened, Eptar automatically inserted double-density stirrups—something I would have taken three days to model by hand.

(If you find a copy of Eptar for AC19 today, treat it like lost treasure. But remember: always run a backup before the “Adaptive Rebar Array” command. Some magic is too powerful for mortal computers.)

I was designing a biomorphic museum entrance—a sweeping, double-curved concrete arch that twisted 15 degrees as it rose. In ArchiCAD 19’s native environment, the shell tool was powerful but flimsy. Every time I added a new window or a heavy stone cladding, the model either corrupted or the reinforcement disappeared into a spaghetti of generic rebars that my structural engineer refused to sign off on.

In vanilla AC19, that meant deleting the shell, rebuilding it, and crying over lost rebar. With Eptar? I simply dragged the shell’s node. The geometry updated, and Eptar’s “Smart Heal” engine kicked in. Within 12 seconds, the reinforcement recalculated—the stirrups rotated, the longitudinal bars shortened on one side, lengthened on the other. The cover remained intact.

I selected my twisted shell. Instead of drawing each bar manually, I typed a rule: “Cover = 4cm. Diameter = 12mm. Spacing = 15cm. Direction = Follow Principal Stress.”

The structural engineer, a crusty guy named Roberto who still used AutoCAD R14, stared at my screen. “That’s… alive,” he whispered.

I printed the 3D PDF from ArchiCAD 19’s new PDF export (another feature I had ignored until then). Roberto took it to the rebar factory. The foreman called me an hour later: “Usually we get flat drawings with 50 conflicts. This file has bending schedules and a 3D view. We can bend the #6 bars tomorrow morning.”

ArchiCAD 19 was a great BIM vessel, but Eptar was the engine that made reinforced concrete honest . It turned the shell tool from a shape-maker into a structural collaborator. And on that museum project, not a single rebar was cut twice.