Use a separate plan for each floor of the buildings if necessary. Note all the following features for each floor

Internal walls and dividers

Stairs

Doors, including sliding or folding doors

Fixed storage shelves or racks

Portable storage

Fixed work benchers, tables, or surfaces

Large pieces of equipment or machinery

Large pieces of furniture

Computers or IT equipment

Toilet/washroom and washing facilities

Eating areas, kitchens, vending machines

Fire extinguishers and smoke alarms