Can you please suggest one which is most efficient and causes less damage?

I'm currently looking to do a flip soon, but I haven't had the opportunity to work with any reliable, quality and cost efficient crews.

Few questions getting started: Do any you out there have tips on what helped you ramp your learning and experience at a more efficient rate? 

The pros of a newer building are less maintenance, More Energy Efficiency, better chance for separate utilities, no worry about lead, and typically higher rents. cons it's going to be a lot more expensive.

It works in REI, but it is the simple way with limited life span of opportunity filled with too much competition to make it the most efficient use of your them and money.I've never worried about the sale price, since whatever the seller and I agree to, isn't what it will actually cost ME anyway. 

People are funny.So yes, I manage about 60 single family homes, and it has improved our process, and shorted the time orders are open simply due to more efficient scheduling.John KingBluefax Property Managementhttps://bluefaxpm.com(210)468-1843

One just lead to a misdemeanor ticket which i'm being summoned to court.Another is he's complaining about his furnace not being efficient enough and threatens to leave.Called demanding an electrician to ground his wires because his cable box fried from not being on a surge protector, threatens to leaveWe increased his rent slightly when we purchased it, which is still $200+ under market, threatens to leave.He's paid every month but is always a week or two late and claims it's insurance related getting back paid.

However, generally speaking is it usually cost efficient to tackle major renovation (without sq. ft. addition) done at the same time or before I do any renovation, I would still first need to bring the existing structure back to code? 

The value in this business is figuring out how you can operations more efficient.

Sounds like you're antsy to move forward, which I 100% get, but not sure your idea is going to create any additional efficiency.