Not safely you could remove the dlc which will remove the house entirely and everything in the house but that will probably cause a lot of bugs. On a PC if you use the command -
That should show some id's for the house i tried it but got no ids for the wings but i didn't have the quest if you can find the id's though you might be able use commands to disable the tower and enable the greenhouse, i would make a new save if you try it just to have a save to go back to if it causes problems after.
Personally though i wouldn't run the risk of making the already sometimes buggy dlc possibly even worse.
I can't quite remember but i believe at the drafting table, you have the three choices for each wing of the house. If i remember correctly, you can remove the unwanted extension and replace it with another one. If not i would go with what Hjalti Ice-Eyes87 said. :P