Delaware follows a hybrid building code adoption, meaning some codes are enforced at the state level, while others are adopted and enforced locally. The International Plumbing Code (IPC) with state amendments is adopted statewide, whereas the International Residential Code (IRC) and National Electrical Code (NEC) are adopted at the local level.

Since counties and municipalities may adopt different versions of these codes and implement specific amendments, it is important to check with local jurisdictions for additional requirements.