I'm familiar with orange trees and an orange tree that reaches the power lines would have a trunk of 4" to 6" in diameter. 

An quick way to check if the zoning was modified to be a small multi is to check with BGE or whoever supplies power to the home. 

If the power doesn't need to be upgraded and you're talking about replacing or installing everything HVAC related you would probably be looking at $5k to $7k if it's a newer house.

Here is some negotiating power i have,  He's offered up another one of his house that doesn't have a for sale sign yet and said he'd give us a deal.  400 for both, similar house, but LOTS more work.  

I learned the power of real estate to build wealth.

Your current buying power might be low but that’s okay.

we are all on separate power meters but the rest is all combined to include a dumpster. 

Hello Keaton,  here are some past posts on ADU's and utilities.On creating a Tiny House Park: https://www.biggerpockets.com/forums/48/topics/440588-tiny-house-park-idea-on-large-parcel-of-landOn billing separately for water:  https://www.biggerpockets.com/forums/61/topics/715598-billing-a-unit-for-waterOn billing separately for electric: https://www.biggerpockets.com/forums/52/topics/422840-split-level-house-with-one-meter-best-way-to-split-utilitiesOn the possiblity of using solar power: https://www.biggerpockets.com/forums/61/topics/716731-using-rooftop-solar-panel-systems-to-increase-cash-flow

As I’ve been doing this research, I really began thinking about the power investors have to make widespread change in how efficient a house is.

With interest rates going even lower, the purchasing power goes up along with property values.