Final answer:
The first wooden member to be laid down on the foundation wall is called the sill plate.
Step-by-step explanation:
The first wooden member to be laid down on the foundation wall is called the sill plate. The sill plate is a horizontal piece of wood that sits directly on top of the foundation and provides a base for the rest of the wooden framework to be built upon. It helps distribute the weight of the structure evenly onto the foundation.