Now I'm not saying you should install that solely because this tenant complained but I do feel that some sort of supplemental heat is necessary in any finished basement space.

I would tell them it is what it is and they are welcome to supplement the air conditioner with portable A/C or window units.

So rentals but I would look at flips.I own my owe business (FX Company for films) and it's slow in the winter so I looked into real estate to supplement my income and keep me from going couch crazy.

I'll use my passive income to supplement me in the early months but will want to get to a point where my passive income goes back into real estate again.

Less if we can make more cash-flow per monthNow, where it can get interesting is any other ways we opt to supplement that income.

In my experience the portable heat pumps do not do as well as ductless in cold weather and I supplement the portable heat pumps with a construction heater in my own home.

Speaking as a US urban homeowner, supplementing our retirement income by running 2 Airbnb units in our 2-family home...The "hotel industry" includes a ton of low-paid workers. 

My spouse and I are interested buying and holding single families and small multi-families to supplement our full time incomes and build our way to financial independence. 

Afterward, if you have the time and patience to write letters and build an email list and whatever, you can do that to supplement your marketing efforts.Feel free to contact me if you want more information! 

Which would be an ideal retirement supplement income on top of our other investments.