I'm planning to buy a SFH in Huntsville in the next 2 months so I'm looking to understand more about the area.My goal is to buy in a B/C class neighborhood for a deal that is expected to be cash flow even.

All depends on the area and goals.In a B-A class where rents are under market and condition is not great, I would prefer vacant, renovate, and rent outlate payments, under renovated, etc are to be expected in C-D class.

You can find some great deals in a B class area here in Chattanooga. 3/2's in B class neighborhoods range from about 200k-235k.

Here is the specific language from Assembly Bill No. 68:a local agency, special district, or water corporation shall not require the applicant to install a new or separate utility connection directly between the accessory dwelling unit and the utility or impose a related connection fee or capacity charge, unless the accessory dwelling unit was constructed with a new single-family home.If the Planning Department is telling you that you need separate utilities and you're adding an ADU to a lot with an existing SFR, refer them to the above language from AB 68.

Working on the rest.We rank them by Class A, B, C & D.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.So, we recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Here’s our OPINION for the Metro Detroit market (always verify each area for yourself!)

Investors would classify neighborhoods as A B C D with A usually being VERY safe and B being acceptably safe and C with variety of levels of crime and D would  be "don't come unless you are armed". 

I was wandering what A, B or C zipcode mean?  

This is a B property in a good neighborhood.

This is a B property in a good neighborhood.

People expecting $200 per door per month in a b class neighborhood while financing with little to no renovation are going to be disappointed.