You want to build a team that way when hiccups/problems arise, your not dead in the water.

With this platform landlords and tenants can have access to important documents, have insights on water/electricity and gas usage, have a better connection trough communication tool, have personal popups, and much more features that will be created.

- Does it require extension of public utilities for water & sanitary service to the lots?

You have also account for items such as property taxes, insurance, repairs, maintenance, contract services (landscaping/snow removal), capital expenditures (roof, water heater, etc.).  

We currently pay water, and the residents pay electricity.

Outdoor complete kitchen with water, electrical and drainage 5. 

A refrigerator can cast $1,000 or $10,000.  

do new buyers have to sign off on properties not yet brought up to public health standards for Drinking water?

Have ALL of your ors in the water, do/setup marketing in many channels (SMS, post card, PPC), learn how to carve out lists that target motivation that you want. 

I started renting a small storage unit where I can keep any extra refrigerator (these had been difficult to find in my local big box stores lately), range and washer and dryer as needed (including if my own washer/dryer suddenly kicks the bucket).