That pedantic technicality aside, Brie is spot on: the 50% rule is a simple a back-of-the-napkin or in-your-head litmus test to determine if a deal is worth further pursuit.Before getting serious about an offer, you want to get *real* numbers for all the operating costs, along with vacancy/bad debt/eviction/turnover history, some knowledge on the area and the tenant clientele and perform a full analysis on the property.

This is napkin math, I didn't add inflation, so it's basically expressed in 2015 dollars throughout.

If you do better great but its a great back of napkin way of determining if a market or property are even in the running. 

You would need to check the specs on the washing machine and see how much {temperature} lift capacity the on-board heater has or what range of input water temperature it requires [Note: some just boost the heat on your tap hot water for things like a sanitary cycle].In the worst case, you could run a hot water line from the house (ensuring that it is buried sufficiently deep ... and probably should insulate it) and the heater in the washer could deal with any heat loss in the water during it's journey.

You people in big cities have a tough go of it with all the zoning and building laws you have to deal with, Im glad im in Po Dunk ville where we can pretty much get away with anything, heck most townships only require a permit for new construction, and a few dont, just a sanitary and well permit from the state.  

I think it's much less sanitary to have a top sheet that gets tangled up and leaves the guest touching blankets or comforters that don't get washed between guests.   

Learn the 'back of the napkin' technique for quickly analyzing if something is a deal. 

She got back to me the following day with all the vitals and I did some quick napkin math to see what kind of deal this could be.

Back of the napkin calcs are showing ~25% COC yields with 20% down, and almost 40% with 10% down.

Rinse, repeat.Some quick back-of-the-napkin math on this.