Here is what you are looking at:
Is the mass correct? Did the software double-count the dead load? Why is the seismic weight different from the gravity takeoff? And most importantly— how can you get a better, more reliable Mass Summary?
| Story | U1 (X) ton | U2 (Y) ton | U3 (Z) ton | | :--- | :--- | :--- | :--- | | Roof | 150 | 150 | 1000 | | 3rd Fl | 250 | 250 | 1200 | | 2nd Fl | 250 | 250 | 1200 | | Base | 200 | 200 | 1500 |
In this article, we will move beyond the default settings. We will explore how to extract, validate, and optimize the ETABS Mass Summary by Story to ensure your dynamic analysis (Response Spectrum, Time History) and modal results are physically accurate. The default ETABS Mass Summary is only as good as your assumptions. Many engineers open the table, see a number, and immediately proceed to design. This is a mistake.

