Depending on if the hot water heater is gas or electric you may have to 1) run new gas lines and exhaust pipe to correctly vent the carbon monoxide. 2) run new electric to each hot water heater. because the additional electrical demand this would cause you may have to upgrade your service (circuit breaker panel). 

\the one I had I condo converted and sold each unit.. that turned out to be profitable.. took back notes so I did not have to manage the individual units and still enjoyed cash flowJay,Another topic...I'm hosting/moderating a panel discussion on real estate development. 

Label the electrical panel.5.   

The first element in the system is your electric meter, which feeds to your circuit breaker distribution panel (or fuse panel in very old homes) with a very large set of wires.

We actually end up paying less to lease my Audi Q5 than it costs to own my wifes VW Jetta when factoring tax savings and maintenance savings. ( All my maintenance is included in my lease)a cute movie that reflects this is Tin Man with Danny devitto  they are 50s siding salesmen.. and the front of the office is one caddilac after the other lined up.when I grew up in my dads land sales business the ride of the day.. was a Jeep Wagoneer with the faux wood paneling.. but now a days you can buy a nice new Mercedes small one for under 40k.. 

I just bought a house last month that had solar panels on it.

Admittedly I had to bump the service/panel up to 200 amp (did that myself as well $800), as the entire home is electric ONLY.

I also went to an event where there was a panel on expansion of existing parks.  

I would have blown insulation in when I bought the house, but I never went up into the attic to see -- the access panel (not door, but yes, panel) in that house is about 18"x20", and I didn't want to struggle with squeezing through. 

Does anyone know of a formula based on the square footage of a house to try to figure out what would be required in the way of solar panels to generate 100% of the electric from the solar?