Welcome to Tiny Homes, an idea that is more popular with minimalists than with neighborhood associations and zoning boards. We'll point out the fun parts. You'll have to check out the logistics and legalities - but this one survived WWII, so it has already survived decades of regulators.
It is a tiny house on a tiny lot, and maybe that's all you need. Instead of thinking of it as a 1 bedroom, 1 bath that is only 450 square feet, maybe it is more appropriate to think of it as a master suite without the rest of the house. The same's true for the property. Maybe it is just enough to have room for a garden, some ornamentals (including some ornamental rocks that might be touchy to move), and a place to park your car; because the lot is only 2,704 square feet, about the size of many homes. For $249,000, you get the basics without a lot of excess; but also some nice, simple style - the sort of pragmatic house that could be expected after the Great Depression and the uneasy times before the restart of war. They call it a rambler, but at that size there isn't much rambling, so consider it a cottage if that works better for you. Now, Seattle's grown up around it so it's close to a lot of things like Northacres Park. Why own more yard when you can walk to acres that someone else will tend?