Quote from @Mary Peale: May I ask which amenities you added that you believe contributed to a revenue boost? 

Is the finished basement SF added to the main SF to get a total SF which I then use as I normally would to get a per SF price or do I value the basement and main floor differently?

You would then stress to not incur any improvement cost above $22,000 or you may have to liquidate the property.In this scenariod, $60,000 if you are making an above return at 10% to 12% annually + $30,000 making $4% in a HYSA, the average return is maybe around 8%The blended return would be about 9%You may be better off investing in the stock market, get a slightly lower return but without all the added stress / work.

good work, @Patrick RobertsI'll also add that on 3 and 4 unit FHA, there is an added guideline and self-sufficiency test.

This could be added at some point.

I've just recently added a coin-op washer and dryer to a 4 unit. 

For example, Intel headquarters, Honda, Amazon, Facebook, Google, Nationwide, and recently Anduril which is adding another 4,000 jobs here!

I totally get where you're coming from—pools are such a great amenity, but they do come with some added responsibility!

In this market, I tend to lean towards adding value to duplexes.

Not to mention, you're adding an appreciating asset to your portfolio.