I am in the process of preparing to move to the Seattle area next summer and as part of those preparations I am planning to sit for the Washington Managing Broker Reciprocity Exam next month. 

Stop try to fit a square peg into a round hole.

I am just south of Pittsburgh in Washington County.

We'll reroof at the same time and maybe bump out the back of the house to add square footage. 

Im not sure if its a square footage thing a number if units thing and/or if i have X number of units if they combine the number of units and classify me as a commercial landlord

This would be items like mortgage interest, real estate taxes, home owners insurance, utilities etc.Pro-rating the expenses have to be done in some logical methodology.If the units are of equal size - they should likely be 50% allocated to the personal residence and 50% to the rental property.if they are not equal - you can pro-rate based on amount of rooms or square footage.

I’ve been trying to get a permit on the Peninsula and my application has been sitting for 7 months and counting.I am curious how much your $/square foot are estimated to be for your proposed ADU.

(S)1.25 = P, where (S) is the number of inches of snow on yourroof, and P is the pounds per square foot of that snow. adds up fast

You're right back to square one.

Apx square footage is 1380.