When self-weights were entered in stages for several levels of the structure, and building masses and loads generated at each stage, the loads due to the lower portion of the wall mass from the storey above were not included in the calculation if the loads were generated from top to bottom. Similarly, the loads due to the upper portion of the wall mass from the storey below were not included twice in the calculation if the loads were generated from bottom to top.

Furthermore, the calculation of total building mass used only the masses from floors that had already been generated, leading to a different result than if the loads had been generated all at once.

These problems lead to significantly non-conservative loading when the loads are generated in stages, particularly when it is done from top to bottom of the structure.

They have been corrected and the program now generates the correct seismic loads when building masses are generated in stages. Note that the seismic loads that are generated for a particular level after the entire structure is complete will be different than those at an intermediate stage, because of the difference in total building mass. The loads generated at the intermediate stages should not be used for design.