Someone could buy on contract and run down business, create further potential environmental liabilities, fail to make payments, and the market could decline.

This is a key element in your investment plan.

We will be focusing on property rehab and buy to rent.Funnily enough, it was a review search on a get-rich property seminar (that had a few scammy elements) that made me stumble across BP.

You can screen well, but as long as the human element is there, you could run into anything. 

An uninsured worker that gets hurt on your property or a contractor digging up a gas line with a back hoe or disposing of toxic chemicals like paint or solvents into an environmentally sensitive area can result in a huge liability that can easily exceed the value of the property.

This is long-term investing for us with a focus on stewardship, good business practices and with a dose of the human element.

I knew it would likely get rejected on paper so I called the listing broker to put a human element to the offer.

This means your buyer pool is limited to people that really want a tiny home and care about the environmental impact reduction their building process has.

There is one other element to the return worth taking into account: the monthly mortgage payments consist of both interest and principal.

People move in and out of roles on a daily basis and I do not think that "retail customer" BEST decribes the role of a tenant in the landlord tenant relationship though it is an element of it.