Changing the 3d model of an object

I want to implement an “upgrade” to a building in my game, when it upgrades the model will need to change to the level 2 model etc.

I’m guessing i could do this by making a gameObject Building, and having a child Object model, load prefabs of level 1 (2…3 etc) building based on what is needed as the model object… but if i was going to do that i might as well just use the prefabs for levels 1,2 and 3 as the main object themselves. Is there an easier way to simply swap a 3d model to a different one ?

My solution to this is to have all the desired models as children of the object, then just use setactive() to enable/disable appropriately.