IBC 2024 Change for Vertical Seismic Design Check
The 2024 IBC brings an important shift for wood-framed buildings: every level in a structure must now be at least as strong—or stronger—than the level above it. Why? To reduce the risk of weak-story failure during seismic events, one of the most dangerous and costly structural vulnerabilities.
In other words, the code now requires that you check that the seismic strength increases as you move down the building.
📐 New Requirement (IBC 2024 / SDPWS 2021 §4.1.8):
Each level must be stronger than the level above. here are limited exceptions, but the goal is clear: prevent weak links in the vertical load path.
What This Means for Your Workflow
This change adds a new layer of coordination to your lateral design. And if your structure changes late in the process—as it often does—it can be tricky to catch all the impacts manually. That’s where LAVA comes in.
LAVA automatically checks the vertical strength distribution of your seismic force-resisting system (SFRS), and alerts you of compliance—saving you time, reducing errors, and helping you stay code-compliant with confidence.
No spreadsheets. No guesswork. Just answers quick.
New in LAVA v26
Support for this code check is built into LAVA v26. If you have questions about how LAVA checks these loads or want to weigh in, we’d love to hear from you. Let us know what you think.