You could just as easily take $40k out 5-10 years in and have negative money invested and infinite COC.The negative cashflow with income property:  I have an expensive oos property I want to retire in.

@Javier Cuevas Santos You want this money to be easily accessible when you need it.

If they are professional, they can explain this quickly and easily.

I found most renters will change the filters if you tell them a dirty air filter means they get the ac man bill.

And, of course, neither of these investments produces cash flow, nor can it be easily leveraged like real estate.I do agree with the sentiment that taking these too far does get one into doomsday prepper-land.

and mine are very easily managed on my own.

Scenes and automations are straight forward easily programmed in SmartThings and Samsung made some big improvements in that recently.

I know I can easily raise them $50 each. 

Mine can set door codes, message (or call) guests, schedule cleaners, adjust the thermostat, monitor my cameras, & call a plumber just as easily as a local PM can, for 1% of the costI wrote much more about leveraging offshore assistants in this post here.

Rules for such things as: how often to change HVAC filters, redo paint jobs, have a gardener come, check smoke detectors etc.Should I have the tenant or landlord pay?