The board decided that the movie merited the rating because of "some violence."
Morgan Creek's executive VP of marketing, Greg Mielcarz, told TheWrap Wednesday that he still believes the film will ultimately receive a PG-13 rating.
"They gave us a list of several things in the movie that they thought should be cut," he said. "We're going to … work with them together to ensure that we receive a PG-13."
The movie is about Will Atenton, a successful publisher who quits his job and moves with his wife, Libby, and two daughters to New England.
"But as they settle into their new life, they discover their perfect home was the murder scene of a mother and her children. And the entire city believes it was at the hands of the husband who survived," according to Universal.
The thriller gets scary from there.
In order to have a rating changed, two-thirds of the members of the appeals board have to agree that the rating is "clearly erroneous."
The Motion Picture Association of America says that the ratings board reviews between 800 and 900 films each year and that fewer than a dozen ratings are appealed each year.
In the "Dream House" appeal, the board heard from Andy Fraser, vice president, physical and post production at Morgan Creek Productions, and Greig McRitchie, executive VP feature post production for Universal Studios. The Classification and Rating Administration was represented by its chair, Joan Graves.