Updating multifamily buildings

[Matthew Wright]

I understand that value is driven by income when dealing with multifamily (5 units plus), but at what point do upgrades/renovations increase value? For instance if I have an 8unit that has old painted cedar shakes and original 60s windows. How can I calculate my return for that improvement, if I replace siding with vinyl siding and put in new windows.... assuming this improvement won’t increase my rents.