It depends. Although Worcester has adopted the Specialized Energy Code, it does not apply to every project. The Specialized Energy code applies to new buildings only. This means a freestanding detached ADU must comply with the Specialized Energy code. However, if your ADU is attached to an existing building, it is considered an addition or renovation and must follow the standard Stretch Energy Code instead. Energy requirements for ADUs are generally less strict, when compared to new homes, to help encourage their development.