Upgrading Building/Town event?

Hi, I've been attempting to make an event (currently testing so it is just simplistic) where the player can upgrade his town/specific buildings as well as clear out the surrounding area for more building space.  I want to do this without resorting to multiple exterior maps.  I have been using the Tile Swap script found at  http://www.himeworks.com/2013/02/17/tile-swap/.  

I am attempting to make it so this building http://i.imgur.com/HPgzC2X.png  becomes one that looks like http://i.imgur.com/lT3Cpt8.png when upgraded.   However, when I attempt to do a Region Replace for the tiles as outlined in the Tile Swap script I linked above, it ends up looking like this http://i.imgur.com/z1GCrcP.png.  As you can see, it did not auto-tile into a building correctly and the shadows remained where they were and did not adhere to the new geometry of the building.   The event I am using for it currently is http://i.imgur.com/ew8LL6q.png (Region 1 is the stone building, Region 2 is the roof. The Position Swap is just to add the new window to the building).  

If anyone could let me know what I am doing wrong or a way to correct it, that would be wonderful.  Alternatively, if anyone knows a different way to do 'Upgrade Building' events that would also be awesome.  I don't want to make a ton of maps and have it so the map switches every time the player upgrades something as I would like to give players a choice as to what order to upgrade things.

Thank you very much for any help anyone can provide.  :)

Can't you just use events to draw the building?

Then make the events turn to a new page where you set the graphics for the second building based on a switch.

I don't know how to solve the shadow issue though.

http://www.rpgmakervxace.net/topic/15689-est-build-and-decor-series

not too easy to use though. (about medium level difficulty)

Awesome, thanks very much!  I'm not super-proficient with understanding scripts but I am slowly bumbling my way through it.  I think I am on track to having things working how I want them to!