There are a lot of considerations like setbacks, lot coverage, parking requirements, height restrictions, floor area ratios, stormwater, utilities, access etc.Assuming you can develop multiple units you could proceed with the development, set aside one unit for your father in law and sell and or rent the remaining units. 

ensure you understand the rules. also understand any income laws in PR, plus any additional tax filing considerations.

Factors such as employment and demand are two key components to take into consideration when evaluating which markets to invest in, as you well know.

Factors such as employment and demand are two key components to take into consideration when evaluating which markets to invest in, as you well know.

Another consideration and a curveball... active investing ...meaning starting with large multifamily (100+ units)!

I've canvased many southern state listings but am struggling to arrive at any particular markets which I feel I understand well enough to make considerable investments.

At the end of the day all the decisions are yours to make.Managing rental properties is tough, it’s time-consuming, and often comes at a considerable cost in terms of stress and heartache.

There is considerable demand for single-family houses and not much inventory to meet the demand. 

As Oregon prepares to implement a new law intended to spur the development of duplexes and small apartment buildings in cities like Salem, a disagreement has arisen over how much control local governments should have over zoning considerations...In 2019, Oregon became the first state to effectively do-away with single-family zoning after lawmakers passed House Bill 2001.

In LA, the expenses ratio "rules of thumb" point to much lower percentages because rents are so much higher (and, side note, the weather is considerable better).The 50% rule says that you should expect 50% of gross income to go toward expenses.