How to Rent out Rooms in Bellevue

[Lili Chen]

Hi everyone, hope can get some help here. 
We recently purchased a SFH in Bellevue (98005) it is 4B 3.75B ( 3 rooms and 2 Bath in the first floor and 1B1B in the basement. We want to rent out 2 or 3 rooms out but not sure what's the procedures. Heard need to apply some permit if I want to rent out the rooms but not sure exactly the process. Here are some of the questions I have:
1. Does anyone know if the permits is mandatory to apply in order to rent out the rooms?
2. Is 2 maximum number room that I can rent out ( anyway I can rent out 3 rooms?) 
3. What is the process of getting permit? Does it involved with lot of inspection and back and forth? other than the permit fee, what kind of potential cost might associate with getting the permit and how much usually cost ? 

4. How long usually take to to completed the whole process? 

Super appreciate with everyone’s help!