The only property I have in the city is over 100 years old and even though it has brand new copper plumbing and electrical throughout, it still ends up having far more problems than my units that are newer builds just by nature of its age. 

NOPE - I had faucet off and new one on and then the drain piece broke, actually fell out bc of the pressure I had gently applied and was already broken anyway - just waiting to fall apart in my hands.

i figured the 100% HAD to apply to something other than the refi LTV.Thanks for clarifying!

It only applies to 3- and 4-unit properties (not SFRs or duplex) bought using FHA financing.

Naturally it depends on kind of actual project from just better house to luxury unique house if this is acceptable for this location.

I believe this year there was a law passed that allowed businesses to write off 100% of their capital improvements instead of depreciating them over time.Again, you would need to check with your cpa and see if that applies to you.

The chimney is either letting cold drop into the house,,,or shipping heat outside by the natural rise of heat.Furnaces /boilers with pvc venting dont. 

I have also seen these percentages applied to highly desirable areas (NW, NC, Far North, & Historic Areas) as well to higher priced flip properties with larger potential net profit.  

I need to buy a house for myself and build my wealth, so naturally looking at multi family.

Naturally discuss it with your local fire department first (they may nix the idea for a variety of reasons) and if you get the okay from them (and they can help guide you through the process), contact your CPA and attorney to find out what you need to do before proceeding with the process to be sure your ducks are in a row.Good luck and remember to bring really, really long skewers for the marshmallows!