I'm an architect so it's helpful to know what is getting approved and what new regulations impact growth.

We are talking architects, plumbing build outs, fireproofing, zoning attorneys, etc. 

The contactor and architect were butting heads and it took 4 months to get the plans submitted to the city.

We have everything approved to get started, all he needs to do is pay the architect and start gutting the property but he keeps rescheduling when we will meet with the architect to provide him with payment.

I'd even go so far to hire a engineer or architect to come in, take a look, and put together a report for you before going the route of excavation. 

The unit would need ground up work, plumbing,  concrete,  architect plans etc. 

I care solely for passive rental income with this part of my portfolio but I am happy to learn to remodel with a hired crew and architect if it signifcantly increases passive income returns.How to Get Started:I need to be on the ground walking looking for for sale signs as I take a trip through Bogota, Cali, Medellin, and Santa Marta.

I employ an architect, which has proven invaluable to avoid costly mistakes, specially seeing that construction is not as standard and regulated as in the first world.

@Brisa MejiaAre you allowed by zoning to add the unitsI would ask your architect what they are seeing ?

You need to talk with a civil engineer or an architect to develop a preliminary site plan (do you have a boundary survey?).