.- Both boilers installed new 2017- Both electric panels upgraded 2015  - Shared Backyard access for bottom 2 units- No Parking, No Central Air- House built before 1900- Roof about 20Yrs old- Assume Fed cuts rate at least .25 point later this year Any thoughts would be appreciated.

They also said i needed to account for common space electricity?

Some genius politician's think oh hey, while we got all this going on, I know, what a great time to create even MORE restrictions on energy, manufacturing logistics, yeah, let's do that....  

This particular unit is an ADU and utilizes my electric/sewer/water so they pay portion....

I assume these areas have strict zoning, permitting, and design codes, along with requiring state licensed contractors to perform electrical, plumbing, and HVAC which would increase costs.

But with 4 kids in their teens/twenties now, seems like that money would be far better used if one of them has entrepenurial ideas (and energy and time). 

Once you find one good contractor they typically know other "rock stars" in other trades (electric, plumbing, etc...) that you will also need.

New plumbing, electrical, and mechanical behind the walls? 

So keep an eye out for any major improvements needed in the first few years of your ownership (roofs, exteriors, HVAC, electrical rewiring, etc) Things to know before starting: Make sure you buy at a basis in-line or below market comps (on a per unit or rent multiple basis).

Side note: Anybody else get some serious "fan girl/boy" energy when people like @Dave Meyer comment on these posts.