As for investing, I'm looking to try to get some passive/supplemental income, hopefully to replace or reduce the money I need to make as lawyer, which is as you know a tremendous amount of work.  

They talked about the following method for those who don't want to be super active in real estate:Buy one house a year, ensure rent covers all expenses at a minimum Have each house on a 15 or 20 year noteOnce you hit year 16 or 21 (whatever you amortize the loan for), start doing cash out refinancesThis method only requires one house (more would work too) a year, and would greatly supplement or even provide a retirement.  

If you are supplementing properties with money from your w2 job and that goes away you will feel some serious pain.

I have also been a Supplemental Teacher at a public school district for 18 years.

Since I’m new in real estate, and at my age, I would like to generate a supplemental income in my retirement even if it’s just one or two properties a quarter.

My goal for 2018 going into 2019 is to supplement my income. 

Or are you going to have another job and this be supplemental. 

@James Freeman Since you need a 4 bedroom, I would recommend that you look into the possibility of building an ADU, Accessory Dwelling Unit, to help supplement your current income.

HVAC codes are supplemental to the IRC.

Would the lender allow the buyer to have supplemental loans up to 75% LTV?