Which studios were used for set construction in how to train your dragon?

The provided evidence does not contain details about the studios used for set construction in "How to Train Your Dragon." No reliable source was found in the supplied data to confirm which production or design studios were involved in building the film’s sets. Because of the lack of verifiable information, I cannot give a definitive answer about the set construction studios.

For a complete answer, you would need to consult official production notes, interviews with the film’s art department, or reputable industry publications that cover the making of the movie. These sources typically list the studios and design teams responsible for set construction, model building, and visual effects.

Until such sources are reviewed, the question remains unanswered based on the evidence at hand.