When do you tear down vs Renovate in a house currently rentable?

[Colleen F.]

Here is the situation,  Have an 1800's ballon construction  3/1 single family , 1.5 story unit.  The  unit is rented consistently and is functional but also needs upgrades, new siding (has 2 layers), Some rooms could benefit from re-wiring and more insulation,   Painting is always an issue as it is not plaster but older thin wallboard. kitchen is fairly new, bathroom could use upgrade, upstairs bedrooms have some pitched ceilings but I don't think based on the foundation/construction it is a candidate for a full second story and it had a new roof a few years ago. It is always going to be a little funky upstairs.   Replacement if the town would go for it would be a duplex with two 2/1s. I think I would have to drill an additional well too.  What makes you decide a property is no longer worth fixing and to replace?   Haven't got siding estimates yet.  To upgrade completely ballpark I think 80-100k but I could just keep slowly chipping at it.  Guess probably 550,000 for a tear down and new build depending on what's required and maybe a year of down time.  Currently gets 2k in rent.  Two 2/1s rent would be close to double that. Another 3/1 in better condition, all full height rooms maybe 2500 - 3 k.  Just looking for thoughts as we consider the re-siding.