I wanted to mention that strategies just like these are commonly utilized by the ultra wealthy in order to do a number of different things.

I don't think all properties need professional design, but it should be consideration for luxury rentals. 

There are mansions and then boarded up drug houses a few streets away...Thanks for the advice!

For your four plex with mostly steps up and down, especially in a region with long winter/wet seasons, I would recommend considering a durable and waterproof option such as luxury vinyl plank flooring.

However, we operated a luxury home as an Airbnb for 5 months with no TVs and no Wifi. 

If you had a luxury product, you knew yours would book, as well—as long as it was managed well and CLEAN.

We are upgrading with Luxury Vinyl Plank (LVP) flooring, this is an appraisal point and they last longer than the standard flooring, The extras windows (free), granite countertops because once again it helps with appraisal but also last a long time and they check a box for renters, and a few layout modifications that i believe add more value and let the units work better given the site layout.

Great opportunity to own a one of a kind luxury Garage Condo located right across the Broncos Training Facility.

If you are somewhere ultra competitive, it may make sense to have it regardless!

For example, there are many networks and conferences of Ultra high net worth individuals at the billion dollar and up level that gather all over the world at conferences looking for opportunities (prior to Covid-19 of course).