The engineering community is actively working to resolve the ambiguities surrounding portable and temporary structures. A dedicated subcommittee of the ASCE 7 committee is developing a standard for wind loads on temporary structures. The fruits of this effort are already appearing in the (Section 3103), and they are expected to be incorporated into ASCE 7‑28 as a new chapter (likely Chapter 35). Future editions of the standard are expected to include explicit reduction factors for short‑duration structures, clearer guidance on public‑occupancy temporary buildings, and harmonized procedures for portable modular units.
However, beware: If your portable unit is stacked (two-story portable office), the 7-22 code prohibits the free-rocking exception. Stacked portables must be treated as fixed-base structures with explicit seismic connections. asce 7 22 portable