R7.0 Accessory Dwelling Units (ADUs) and the Massachusetts Stretch Code

In February 2025, the Massachusetts Residential Stretch Code added a new column in Table R406.5 relating to accessory dwelling units (ADUs). This course takes a deep dive into ADUs and discusses what ADUs are, how they are different from existing building additions, which stretch code requirements apply to ADUs, and how to apply Mass Save Incentives to ADU projects. The course also reviews some frequently asked questions, as well as case studies that highlight different scenarios that you may encounter when working with ADUs.

Learning Objectives:

1. Determine when the ADU HERS Index values in Table R406.5 apply to projects.
2. Distinguish between an accessory dwelling unit and an addition.
3. Judge the appropriate compliance pathway for existing building projects.
4. Evaluate which code provisions are required for ADUs.