There are multiple ways to invest in RE: single family, multi-family,  long term rentals, mid-term rentals, short-term rentals, rent by the room, commercial, co-ownership, syndications (I personally won't do syndications) etc. 

If the home is 100 yrs old, I'm assuming it's a definite gut which is going to require new plumbing, electrical, heating, cosmetics.I spent about $140K reno on my multi family in the heights on NY ave and there were massive problems with it but it was a gut to 3 units & adding 2 bathrooms, 3 brand new kitchens 4 bathroom reno in total, all new flooring, sheetrock , insulation, framing, doors, electrical, plumbing, paint, parts of roof etc.

They already have a track record (good or bad) with you, so you can decide based on payment history, inspections, etc.

I was going through the rent control laws ( I know, should have done that before purchasing the property ), and a section stands out. https://ecode360.com/30526708#42037155Based on what I can read, the rent control chapter doesn't apply to: Dwellings of three and four units, at least one of which is occupied by one or more of the owners thereof.My understanding is that rent control doesn't apply to owner-occupied multi-units. 

When running numbers, especially on small multis more western markets with direct access to NYC tend to be more favorable from the numbers stand point and many of these towns offer 30 minutes or less taking commuting lines.

Quote from @Eamon Conheady: I was purchasing a multi family through an IRA LLC and was utilizing debt to finance it, requiring a non-recourse loan.

.- One of our projects has fallen so far behind that the only viable option to get back on track is an early exit.

I've done pretty well as a relatively novice investor in the stock market, just investing in S&P 500 tracking index funds.

But it's a start.While track record is very important, learning how to interpret a track record is just as important. 

As a Spaniard currently living in the Netherlands, I have experience in both markets and can offer you a comparative perspective based on our track record.In the Netherlands, flipping projects typically generate net profits of 10-15% after renovations.