Permitting Single Family Home with and ADU

[Trevor Murphy]

Background: 

I live in the greater Seattle area

-Iv house hacked a single family home (2 story / 3 bed / 2 bed) 

-10% down, purchase price $583,000, took a loan out on my stock portfolio to pay for the remodel (4% interest rate)

-Looking to refinance in March and wrap my remodel loan + home loan together

-I did a complete remodel of both the top unit and lower unit, planning to live on the top unit and rent out the bottom unit ($2000/month) *the mortgage is $2800

-I would like to have two separate mail boxes for each unit. I talked to the permitting department with the county and they said I need to apply to permit the top unit as an ADU.

My question is:  

-Does permitting the top unit as an ADU have any positive or negative effect on the value of the home?

-Would you guys recommend getting this permitted?