Okay, so your house blueprint no longer needs the variant logic, since you don’t want it to cycle through houses once it is placed.
So instead, in the house blueprint, all we have are the variables CurrentIndex and Houses (as well as whatever you had prior to this answer). This is where you set the values for those variables.
In the Building_Ghost is where the variant logic will all go (this includes binding the events). Instead of replacing everything you already had, this is simply added on top of what you already have in the Ghost blueprint.
The above “Create Building” event is the interface event you had previously implemented. There’s simply some added logic on top of this. So now we can get the CurrentIndex and Houses variables from the spawned house.
What the NextHouse and PrevHouse events do is almost exactly the same as what they did earlier, except this time they run an ‘Interface Call’ (not a message, though that would technically still work) to Create Building, which will again create the next or previous house variant, set the appropriate variables as you had done before, and destroy the actor again.
Your ‘On Spawn’ function would just need a simple addition of the variables to be set (except the array, which cannot be passed by reference through the custom node for some reason).
*This image is missing a few of the boolean variables you had set in your previous image. I will stress that you should keep the work you’ve already done, and add the appropriate nodes on top of the work you’ve already done.