I am a buy & hold investor. My current goal is to maximize the cash flow from existing properties while enhancing property valuation from any renovation work I might need to make in achieving the higher cash flow goal.

I am experimenting on the co-living (PadSplit) business model at one of the properties (3Bd/3ba SFR). My plans call for adding 2 more bedrooms & bathrooms (790 sq ft). I have plenty of room in the backyard.

What I need input on is: Which is the most beneficial method in increasing property value? The additional 790 sq ft as a detached stand alone ADU or as an extension to the existing home (increased footprint)? TIA!