Seismic analysis

[m b]

There are two 4 storey condo buildings with no seismic separation gap at two stretches around 40% of the common side overall.

One building floor levels are at the mid floors of the other one.

Should any seismic analysis calculation for one building take into account the adjacent structure e.g. using Sap2000 or it is enough to take the single building alone and ignore the other one?

Thanks