Here's the drawings all done again giving you more information regarding each of the elements and their uses. Note: none of the drawings are done to scale.

This is a section through the warehouse and the showroom wall. It highlights how the connection of floating ceilings is done, also focusing on the junction between the two different levels.

This section is taken wher the rafters are running parallel to the direction in which the section is cut. Pad footings are required where extra support in taking the loads to the foundations, ensuring that he structure is stable.

This is the section through the warehouse wall. The rafters are running into the page to give you a direction in which the section is taken