The Florida Department of Environmental Protection (DEP) regulates septic in FL.

For overlay zones I often look at this site:https://scoutred.com/Overlays are important especially since your lot is in Point Loma so there is a good chance you are in the Coastal Zone, and the canyons are often considered "environmentally sensitive" land, both types of overlays often require additional processes for permitting your project. 

Some differences between SFH and MFH (4+ units):-you will need a licensed architect-you will need a licensed M/E/P engineer-you will need a civil engineer for the usual grading/drainage, plus consolidating the 2 lots and/or the condo split for the townhomes-there may be other consultants required for landscape architecture, environmental studies, etc.

I'd agree that with the high(er) price points, one just has to be careful not to make crippling mistakes being critically conscious of neighborhoods and asset specific attributes. 

Bias: Whether conscious or subconscious, there is no denying that bias can exist when it comes to property valuations.

I will want to be responsive to their needs but conscious of not spending top dollar for every little fix. 

You need to know these, communicate them effectively, and be conscious of making concessions.

The nuances of each asset class tend to be unique from a land use, environmental, and especially valuation and leasing perspective.

The more you deviate from your original agreement, the more someone will feel like they can take advantage of you and the situation (whether consciously or subconsciously). 

https://www.vdh.virginia.gov/southside/environmental-health-...