@Long Dinh   A lender should be able to do a "what-if" simulator on your credit report. 

Many things listed would be considered significant services and would have you losing much of your tax deductions.I know of a couple of STR owners who had to eat a big tax bill due to this and they had to nix those sorts of offerings.That doesn't mean you can't create the wellness space, golf simulator, upscale game room, etc to enhance the space.

But just like people simulation stock trade, would be cool to hear what people think! 

No matter how much time and money was spent on renovation, trying to simulate heavy use of the mechanical systems as a result of the occupancy by a family was different.

Watch the auctions for a month or two (do some simulations for practice) before you actually bid.Otherwise you will likely run home with your tail between your legs.

Here are the links to the calculators I utilized to simulate these hypothetical scenarios.

Golf simulators have come way down in price ($3-5K for a basic unit and setup) could also work in a garage, but not an interior room.

I simulate the situation by pushing the tank back with my hand and flush it.

Simulate paying the same amount (let's say $3,000) each month toward just your mortgage vs. funneling it through a HELOC.

I have been trying to simulate different scenarios by buying property with 20% down and none of them show a positive or not even close to be breakeven.I'm willing to invest in different states but all this is new to me and it's complicated.Thank you.