The reason I say this is that with a 5+ unit a lender will evaluate based on NOI and a cap rate, so adding a 5th unit COULD (or could not) substantially increase the value of the building and make it worthwhile to refinance and pay off the existing loan (that is tied to the "old" quad) anyway.

I recommend you do this annually to adjust for utility increases and other variables.

Also, gifting real property generally would require an appraisal as well, which could increase costs, too.  

But, insurance costs are likely to rise, making getting mortgages for most people even harder to get.What is likely to happen is more creative financing going forward, private lending to increase and smaller houses being built in the future. 

And as time goes by, rents will increase and your income will look better and better.My first investment in 2004 made $35 more than the mortgage.

I still think it is a good area to invest in despite the increases in cost.  

With $100k in equity, you might be able to secure financing for a smaller rental property without significantly increasing your housing payment.    

Last year was back to earth; a glut of available properties drove the rates down for everyone and a drop in visitors also increased vacancies.

Listen to Brandon Turner's podcast where someone he interviewed shared how this made a HUGE increase on her income: https://open.spotify.com/episode/1bS4eL80KL1rWY4vyCMjXh?

Additionally, what do you look for in a property to increase the value i.e. what are typical items to target?