To increase income, you could do this through collecting more rents. You could also collect more fees or provide other services besides renting the apartments.
By increasing the value of the property, the Loan-to-value ratio goes up.
The result of increasing your income and reducing your expense is higher net profits. I do not know too many investors who would be displeased with this result.
You know the adage in real estate that kitchens and bathrooms sell houses. Well, it is true in apartments too.
Turning 2 bedroom 1 bath units into 2 bedroom 2 bath units can be a great way to increase the rental potential of your multifamily property.