It can't possibly be sanitary, or legal, to have a pet urinating indoors.

Technically you could buy the house by signing the deal on a napkin, though I don’t believe anyone will advocate that. https://www.trec.texas.gov/taxonomy/pdf-category/contracts-forms-applications

You can write up a contract offer on a napkin.

I pour over MLS listings in my spare time, running back-of-a-napkin analyses as I go in order to develop more comfort with the numbers, and I’ve started scouring tax lien auction listings in my county.

I know that the best thing to do is to make actual predictions about expected and predicted expenses rather than use back-of-the-napkin formulas.

Plates, napkins sheets, spare sheets, etc.

Have you ever done napkin calcs for those numbers?

These alone prevent midnight "my toilet is plugged up calls" a.Landlord informs the Tenant that the sewer system of the Premises is not designed to accept many types of items, included but not limited to, paper diapers, sanitary napkins, tampons, and children’s toys, balls of hair, grease, oil, table scraps, clothing, rags, sand, dirt, rocks or newspaper.

for napkin math if you think rents are accurate and they look pretty strong even for Oregon coast.just deduct 50% for cost then back out proposed mortgage expense and see where that leaves you.two numbers one gross income other 50% gross income deduct.. deduct mortgage.and do remember Oregon coast is weather wise pretty brutal as you know so cap ex will be far higher than other areas of the US>.  

Location specific of course for properties in proximity to hazard areas.Rules of thumb are nice for napkin calculations, but its definitely worth drilling down.