Fairfax County is proposing changes to the current ordinance, but nothing has been approved yet (https://www.fairfaxcounty.gov/publicaffairs/county-proposes-changes-accessory-dwelling-units-and-home-based-businesses-better-serve-residents).If you can find a home where you can create a smaller, independent space with its own living, bathroom, and kitchen space, you can rent it as an apartment.

You essentially create the "needs"(needed for loan approval: ie- roof with 3+ years life, etc) and your "wants"(That Brand new kitchen/bath all renters want).

Essentially we hadn't begun the process of putting together our spreadsheet that runs the numbers, knew what kind of properties we were looking for, or even how to be a proper and ethical landlord.

I can't give specifics on that area but I am going to be 80k into a rehab that structurally was good, but needed all new electric, plumbing, roof, windows, moved walls, added 3 bathrooms, new kitchen, all new floors etc. 

Key criteria for a successful SFH househack:Suitable zoning criteria, i.e. room rental laws (county by county)Within 1 mile of hospital, major company HQ, public university, and private university (to attract 20-somethings)At least half as many bathrooms as bedrooms (i.e. a 4 bed / 2.5 bath could work, but 4 / 1.5 could get sticky)Plenty of driveway space / street parking (1 per roommate)Plenty of kitchen space (since the kitchen is the most occupied room other than individual rooms)Basement or side entrance entry point (i.e. if you wanted to turn the basement into your living space, you could enter from a side entrance)Un-involved neighborhood community (cul-de-sacs can be the worst spots)Turn-key quality (i.e. you won't need to fix much of anything when you move in)This list is by no means exhaustive, but things to think about when you work with an agent on a SFH househack.

Honestly, if you want to BRRRR, it might be better to try to find those deals now, just look for ones with minor rehab (paint, floors, maybe new bathroom fixtures) and you'll start building up a little rehab experience without the risk of doing a larger rehab.

Not sure if that makes total sense, but essentially scale out to 10-20 doors via lease/options instead of straight rentals.

He would build then sell the house + lot (it's essentially a loan to him so he has some capital to play with since it appears most of his is currently tied up). - The return has a hefty minimum but can go higher depending on the sale price

We had new windows installed, kitchen and bathroom gutted and put together, floors re-done, paint throughout, and landscape completed.

As you know rent is quite low (median in Milwaukee is about 1,200 for a single family) yet you have the same infrastructure to maintain: one kitchen, one bath, one HVAC, one water heater etc - cost of replacing a water heater is the same, no matter if your rent is 700 or 1200 or 1600 (which is our typical rent for a SF).Income (rent) is a function of size: bedroom and bathroom count as well general space meaning square footage.