The main location had to be changed only a couple of weeks before filming, as the original cabin was located in a lake that had frozen. It was impossible to get there by boat. The cabin used in the film is owned by the costume designers parents.
It was very difficult to get a dead swan for the film. A few weeks before filming the team got in touch with a guy who picks up roadkill, and he claimed that he had kept a dead swan in his freezer for two years. They had to drive two hours to a small town in Norway to meet him in a parking lot. He arrived in a pickup-truck, and in a brown paper bag he actually had a frozen dead swan, that he gave to them.
Rikke Gregersen (the director) fell in love with the building in the opening scene from a picture she found on Instagram. She contacted the girl who lived there, and the girl agreed to let the crew film in it. But they still had to get an apartment in the identical building across from it, and walked door to door asking, without anyone saying yes. As they had almost given up, they checked the name on the mailbox from the one apartment where nobody was home, and it turned out it was a boy from Rikke Gregersen's film school who lived there. And he agreed to letting them use it.