Off-site construction has inherent advantages over conventional construction in terms of sustainability that extend well beyond lower construction site waste, yet the common building sustainability rating systems in the U.S. and Canada provide little or no credits to reflect prefabricationäó»s sustainability-promoting characteristics. As project owners in the U.S. and Canada increasingly demand that their projects receive certification by one of the common building sustainability rating systems, off-site constructionäó»s inherent advantages over conventional construction in terms of cost and time may be reduced by off-site constructionäó»s lack of advantages in terms of sustainability rating credits. After identifying sustainability rating credits that favor off-site production and other credits that disfavor off-site production, the paper concludes by identifying actions off-site construction producers should consider to increase sustainability rating credits for their products.