Running a Duplex out of a SFR

[Jeremy Benezra]

Does anyone operate a duplex out of what is realistically a single family residence?

I purchased a house in Federal Way, Washington that has an upstairs kitchen and a downstairs kitchen, separate entries...  I'd like to lock the door in between upstairs and downstairs and rent out the downstairs unit and main floor unit separately to 2 separate tenants.

The house is not zoned as multifamily, it's zoned one SFR per 7200 of lot space and I'm 9000 something.

Do you think I will run into trouble with City or County?  Is there any specific terms I should put into the lease?

Electrical, plumbing, and heating are not split between upstairs and downstairs, though downstairs has in-wall cadet heaters. So there will have to be some friendliness/cooperation between the tenants upstairs and downstairs.

What about refinancing? Will it be more difficult to refinance with my 2 tenants and 2 leases vs if I had the whole house rented out to one tenant?

Thanks for your insight!