Combining two or more models in ETABS
1) You can open Open two ETABS sessions. For this example, let's say Model A and Model B.
Model A
Model B
2) Select the entire model say in Model A , use Edit by using the Edit > Copy option Option command or Cntrl Ctrl-C.
3) Now go to Model B and the use Edit > Paste Option or Ctrl-V to merge Model B into Model A.
4) Set Next, change the coordinates and rotation for the pasted model , you in the Paste Coordinates form. You can see a preview of the model if you place the cursor over OK.
5) Click Ok OK and the two models will be merged.
6) Additional models can be added by repeating this process.
Note: The procedure above assumes that section properties used in Model B are also present in Model A, and you . You may need to reassign loading.