It really depends. Adding an ADU may change the classification of a property under the building code and introduce new requirements that impact the new unit, or the entire structure related to things like life-safety including, but not limited to, egress, sprinklers and fire alarms. For example, if your proposed ADU constitutes a third unit to an existing structure, it will require Fire Protection Systems. However, each situation is unique; you should contact Inspectional Services by emailing inspections@worcesterma.gov to discuss your specific proposal.