Can I time gut renovation?

[Yejin Mun]

I own a victorian house that was fully gut renovated/modernized 18 years ago. (I bought it 3 years ago)
I'm trying to see how long in the future I will need to do another gut renovation, so I can start saving up some money toward it.

Things are in pretty good shape. But given that the renovation was done such a long time ago, there are some wear and tear, like Window and HVAC, shower handle and stuff, so we have been updating those one thing at a time, and I'm hoping that this house can handle another 20 year so the $ we poured in for the new set of windows are worth it...

Would appreciate any thoughts!