Mortise Housing calculation clear up ?

[Lennyzx11]

I've read forum posts and watched Jim Rogers videos on the subject but still have some confusion regarding Brace mortise/Housing layout.

Does the Housing depth start from the "outside" of the inner perfect timber when square rule is being used?

If my reference face is on the "let's call it the West side of the timber". and the 5.5" edge on the East side is the edge of the perfect inner timber.

However the true timber width is 6.5" from West edge to East edge.

Is the Housing cut down to the 5.5" mark(perfect inner timber edge). Making the Housing 1" in depth?

Why I ask. If there is a 1/2" deep housing called for, does that mean to cut 1/2" into the 5.5" inner timber? 
That would make the housing in my example 6.5"(true depth) -1"(to get to inner timber face) - .5"(Housing requested in plans) = 1 1/2" (true housing depth)

My problem is exactly where to locate the 3/8" mark mentioned in order to draw my brace mortises correctly.
From the true timber edge? From the perfect timber East edge, or from the housing bottom edge?

Did I do that right?
Thank you,
Lenny

[Jim_Rogers]

Housing dimensions are pulled from the reference edge towards the housing. If your timber is 6 1/2" and your inner timber is supposed to be 5 1/2" then yes, a 1" housing will be needed.

The inner timber is 5 1/2" to maintain the correct size and location for the housing and mortise. Do not cut into your inner timber with the housing. The housing is removed from the extra outer timber to expose the inner timber.

Did that help you?
If not ask again.

Jim Rogers

[Lennyzx11]

Thank you Jim. That's exactly the clarification I needed.
Lenny