Most swans will not enter a structure unless you physically place them in the shelter and then lock them in for the nesting season. Swans need water to bathe and preen, so this is going to be a labor intensive undertaking if you want to keep them in a "house". You can place them in a pen (1/2 on water and 1/on land, enclosed top to bottom to prevent predation with a feeder inside. Straw should be placed in the pen on the land end to allow for nesting. Again, there is no guarantee that they will nest in the pen if they are accustomed to being out on the lake and the chain link pen will still be open to the weather elements.

If you check out Bob Knox's website (Knox Dog and Swan), he has photos of a nesting box that he uses. The nesting box does not act as an enclosure, but rather a floating nest that assists in keeping the nest from flooding and allows the adults and eventual cygnets to access the nest by floating up into the nesting material. Again, there are no guarantees that the birds will use the box, but if you provide suitable nesting material, they may get used to it. The Regal Swan