Resources and Best Practices
Code Guides ,Best Practices, and Program Forms
For more detailed building science technical information, see the building science resources.
Utility Program Rebates Documents
Massachusetts - 2026 Mass Save forms
Connecticut - 2026 CT RNC forms:
Resources
Ventilation guidance - code requirements - HRV and ERV recommendations and configuration options
Slab Edge Insulation - best practices and strategies
Full Stretch / Specialized Code - Current Stretch/Specialized Code (225 CMR 22) based on the 2021 IECC .
DOER Map of Stretch Code / Specialized Stretch Code towns - updated regularly