The reason that the swans will not go in the house is that it was moved and they are confused as to why it is not in the same area that they have used previously.

Why was the house moved? Is it possible to place it back in the same area that it was located last year? If not, you may need to physically capture the swans and place them in the house. It is very important that you do this quickly as the weather will become more severe increasing the chances of predation by a predator, drowning, starvation, dehydration or stress which can lead to injury, illness and even death. The Regal Swan