Not exactly the same thing.

Upzoning allows the owner to build more than one residence on what was a single family property. This might include removing an existing home to build a duplex or triplex, dividing a house into a duplex, or building an accessory dwelling unit on the property.

Urban renewal was typically the government using eminent domain to raze whole neighborhoods to build low income apartment buildings or some such. This also might include using the "Tower in a park" architecture that was all the rage at the time, but a terrible urban form.