A wall added to divide the living area from the bedroom and an egress window in the bedroom.I have not priced out for the area but I assume I can rent it out for 600/700 Looking to see does this blur the lines of house hacking or is this considered a full on "ADU" within the property.

This may involve cutting through the exterior walls and installing new openings.8.

Also, sometimes a city will stop you if you remove an outside walls to repair it and they will make you basically condemn it as uninhabitable.  

They can gaslight you, but that is just a distraction.They actually sell wipes to detect pot residue on walls, but I am not sure if they work and I would not spend the time or energy in engaging in establishing "proof" - you'll put up walls and they'll just dig more tunnels.Instead, I would:Contact their case worker ASAP, cite the behavior as a lease violation with her, and state that in addition to it being a breach of lease, it is creating health concerns for your family. 

I guess a lot will depend on how you will be able to separate the two properties (eg a fence, wall). granted, if you start construction at 6 am, your reviews won't be kind to you 😄Another thing to consider is that Seattle is not really a touristic destination in the rainy/dark months (I live here too) so you might not even recover your investment to setup the airbnb depending how soon you'd sell it. 

Quote from @Jaron Walling: Quote from @Jules Aton: My biggest waste of time has consistently been hold ups in renovations.  

I remember when I started about half of the listing had the almost exact same accent wall.

I wound up buying Class C SFH in 2023- the feedback from property managers was that more desirable tenants will pay more rent to not live next door to someone with shared walls/ceiling/floor.

In a little place we call Crypto and Wall Street. 

Once they get established, they tend to spread between units through walls, outlets, and plumbing chases.I’d recommend a coordinated treatment plan for the whole building rather than trying to pinpoint one tenant as the source.