The house featured in the movie was re-created to resemble a real house located just outside Westport, Ontario, Canada. Originally, the plan was to film at the actual location near Westport; however, due to actor scheduling constraints, it would have required shooting during the Canadian winter, which was not suitable for the film's storyline. Consequently, the production team opted to construct an exact replica of the Westport house in Australia.
Based on Iain Reid's second novel of the same name. Movie rights were secured for the book before it was even released.
Cinematographer Mátyás Erdely revealed he and Garth Davis wanted to shoot the movie on 35mm film but the low budget and no film labs being available in Australia made them switch to digital.
The two lead actors, Saoirse Ronan and Paul Mescal, are both Irish but their characters have American accents.