|What Does A Shear Wall Do|
The shear walls in a home proved horizontal strength to the home. With out the shear walls the house could fall down. Like the wolf in the three little pigs. With a strong wind you could blow the house down.
The hold downs connect to a post at each end of the shear wall. These post are attached to large anchor bolts or S bolts that are set into the concrete footings. This is where the shear wall gets most of it strength from. The sill plate also attaches to the concrete with anchor bolts. The anchor bolt size and spacing is determined by the engineer to provide the desired strength needed for the shear wall.
Plywood is nailed on to the shear wall framing to give it even more strength. The size of the plywood and the grade of plywood used is also going to be the structural engineers job to determine.
The plywood is going to have to be nailed with certain size nails and spaced apart at certain measurements. The shear panel nailing will be specified by the engineer and approved by your local building department. More on shear panel nailing.