Tenant rent a room but oppose the landlord to enter the house

[Dang Nguyen]

Hi, I need some advice regarding my rental property. I have a rental property in Seattle, Washington. I only leased out the room, not the house and I ensure that the detail of the premise was described very clearly in the lease agreement. There was a time that my wife has to come there and stay overnight due to her work. She only stay in the living room of the house which is the common area. One of the tenants said that the landlord cannot enter the house without giving notice. I said that the leased out premise is only the room and we never enter their room without giving notice. We enter our house and just stay in the common living area. The tenants then said that he contact the tenant union and the tenant union said as below.

"Although the space I/we individually occupy is just our own bedrooms here, it can't be considered the only parts of the house we each rent from you. The specialist made it clear to me that landlords aren't allowed to rent out a space that doesn't include a kitchen area, so my living space extends to the full house by default. It isn't just the bedroom because it can't be considered a livable space on it's own (there is no kitchen in my room)." 

Can someone who expert on this matter confirm if this is true? I doubt it because there is so many micro-apartment out there that don't even include the kitchen (https://www.seattletimes.com/business/real-estate/seattles-newest-apartments-prison-cell-with-no-door-for-toilet/). I cannot find any law statement saying that rent out only a private room can be extended to a whole house and not allow the landlord to enter the house. It's reasonable to not enter their private room but not allow to enter the house and stay in the common living area is so ridiculous.