Etabs Mass Summary By Story Jun 2026

ETABS reports the coordinates (X, Y, Z) of the center of mass per story. This is essential for calculating accidental eccentricity and torsional irregularity (per ASCE 7 Section 12.8.4.2).

Next she compared imposed loads used to compute masses. The mass summary reminded her of the live load reduction she’d applied per code: residential floors used a reduced live load factor, but the rooftop mechanical area still used full live load. That explained a spike at Story 11 where the plant room sat. She adjusted the live load assignment—moving some equipment to a lower floor—and watched the mass numbers settle into a more uniform gradient. etabs mass summary by story

Code base shear ($V = C_s \cdot W$) uses this $W$. If the Mass Summary shows incorrect $W$, the design base shear will be wrong, leading to unsafe or over-conservative designs. ETABS reports the coordinates (X, Y, Z) of

The in ETABS is a standard output table that aggregates the distributed and point masses assigned to a building model at each floor level. It serves as a primary verification tool for structural engineers to ensure that the total seismic weight used for base shear calculations is accurate and adheres to building codes. 1. Accessing the Table The mass summary reminded her of the live

For many engineers, this is just a table they check before sending off a report. For expert modelers, it is a diagnostic goldmine. An incorrect mass summary leads to incorrect base shears, unrealistic drifts, and a fundamentally unsafe design.