In some jurisdictions a common mechanical room needs to be fire separated from the remainder of the building depending on the fuel source used for heating.

I would investigate what mechanical systems were replaced, the roof, foundation, etc. before plugging in a CapEx number.

Particularly, I am interested in note investing, mobile home parks, and multifamily. 

Or only do the 5% down, and invest in a mobile home, which will run around 55k, with pad fees around 500$ a month and interest at 3.5%Thanks!

Anyone so engaged has created a ticking time bomb for themselves.( * Since trailers- mobile homes- manufactured homes are, in fact, residences, the sale or finance of them are subject to compliance with a whole range of federal laws, including the SAFE Act.) 

I have bought numerous multi family units from 2 units to 240 units, from block apts to mobile home parks.Yes I have used realtors and referrals to get the deals but 90 percent of my deals I originated myself using public records.Every property appraiser in every county has a database of every single property in that Is in that county.

Looks like I can get started very soon, just have to get to a computer, the Mobil app doesn't let you send PM's.

I invested in mobiles, then single-families, then multi-families.  

I am not a lawyer, if you hve receipts for hvac work done with the address of the property on the receipt, you could look into filing a mechanics lien (but that may only be for venders).  

I've got 12 mobile homes about 2 hours from my house and it takes up about 6 hours of my time per month.