Look up typical rated load, shaft size and door width for a passenger elevator by capacity — a planning reference, not a manufacturer's exact spec.
These are typical, commonly-published reference figures — not a fixed international standard. Exact shaft dimensions, pit depth and overhead clearance vary by manufacturer and by system type (traditional traction vs. machine-room-less). Always get exact dimensions from your chosen elevator manufacturer before finalizing shaft construction.
Elevator capacity is rated by weight, using an average assumed passenger weight (commonly around 68-75kg per person in most design references) — so a '8 person' elevator is really rated for roughly 630kg, not a hard headcount limit.
The figures here are typical planning references seen across multiple manufacturers' catalogs, useful for early architectural planning — but exact shaft width, depth, pit depth and overhead clearance differ between traditional machine-room traction lifts and modern machine-room-less (MRL) systems, and between manufacturers. Confirm exact numbers before finalizing shaft construction, since a shaft built too small can't be corrected after the fact.
Elevator shafts need to be designed into the building from the structural drawing stage — retrofitting one later is far more expensive and disruptive than building it in from the start, even if the final lift model is chosen later.