Modular construction is redefining how buildings are designed and delivered — and cold-formed steel (CFS) is proving to be a critical part of that evolution. With its high strength-to-weight ratio, design flexibility, and integration into off-site fabrication, CFS framing fits perfectly into the modular construction model.
But one challenge persists: ensuring adequate lateral stiffness and seismic resistance in modular systems, especially when units are stacked. A recent 2025 study published in Structures addresses this issue directly — and its findings closely support the engineering principles TSN applies every day.
Study Overview
Lateral stiffness of modular steel structures infilled with cold-formed steel walls (Read the full article )
What the Study Shows:
- Cold-formed steel infill walls (CFSWs) significantly increase the lateral stiffness of modular steel frames.
- Connection detailing — specifically the method of fastening CFS walls to frames — directly affects lateral performance.
- A simplified model using axial springs to represent studs accurately predicts system behavior, validated by quasi-static full-scale testing.
- Openings in walls (like doors/windows) reduce stiffness but can be addressed through design adjustments.
TSN Products That Align with This Research
The Steel Network has long provided framing solutions that provide drift resistance, lateral load transfer, and deflection management — the exact parameters analyzed in this study.
DriftTrak®
Designed to allow in-plane lateral drift and vertical deflection at the head of wall, DriftTrak® allows modular or panelized systems to deflect appropriately — without compromising connection integrity.
VertiClip® SL & SLB
These clips transfer horizontal forces while allowing for vertical deflection of the stud relative to the structure. They support the behavior modeled in the study, where studs act as energy-dissipating elements under lateral load.
Flat Strap Bracing Systems
For panelized CFS walls used in modular applications, TSN’s StiffWall (flat strap bracing lateral) system and preassembled components provide shear resistance and reinforce wall assemblies with consistent, test-verified detailing.
Design Takeaways for Modular Engineers
- Don’t overlook the structural role of infill walls — especially in modular systems where every connection counts.
- Use engineered clips and connectors that account for both in-plane drift and out-of-plane deflection.
- Incorporate tested systems like DriftTrak® and VertiClip® that reflect actual structural behavior, not just theoretical assumptions.
Supporting Innovation with Proven Solutions
At TSN, we’re committed to engineering products that not only meet the demands of today’s modular building industry — but push the boundaries of what cold-formed steel can achieve. This research is one more reason to rethink how CFS walls and modular frames interact — and to design with performance, compliance, and constructability in mind.