I am responsible for water, heat (gas or oil), common area electricity. 

I have a building that is killing me on heat - which I provide.

Unit has central air/heat with programmable thermostat.Laundry (full washer and dryer) is conveniently located in upstairs hall outside bedrooms.

Great if you plan on using pool heating as an optional upgrade 

The the sellers can properly make an educated decision, but then how many people would want to buy a house where the foundation is end of life and to fix it is a 20k expense.The void wall is not that big of a deal as long as the home can properly cool or heat, which I believe just roof insulation and the right tonnage will accomplish. 

Hi Chris.Gas + solar heating is fairly economical.

Other potential requirements are size (10'X10' as one example), having a closet, having heating to the room, having proper electrical outlets in the room, etc.Look up your local municipality building codes to ensure you have it as a legal room with permits so it can be added to the assessed details/title.

New appliances, water heat & softener, roof (hail from 2018 got me a new one for under $1200). 

For example, they may be looking for single-family homes with at least 3bed/2bath, attached garage, central heat and A/C, and a fully fenced back yard.

If I put the two bed 1 bath rents for 800 that is 2400 for those ...the studio I am adding will be another 650 So 3150 for apartments ..With 13 storage units at 55 that is 715 a month but I am adding a larger 14th unit that I will rent for 150 but let's say 100 bringing the total to 815 for storage So 3150+815 =3965In a cap rate appraisal you exclude the mortgage, tax, insurance and cap Ex So expenses are ..Heat 200Water 75Trash 75Landscape/snow 75Repairs 120Vacancy 120Miscellaneous 200That's 865 in expenses but let's say 900So 3965-900= 3065 in profit (noi) x12 months in a year=36780You divide that by the market cap rate..which I am going to use the most recent data of 7.45%36780÷0.0745=493,691can't be right.