Any building or residence can be sampled together as long as they share a few features:
Every dwelling in a sample group must have the same:
- HERS-tested measures, i.e. CF-3R tests
- Installer/Builder for the Mechanical forms
Every dwelling eligible to sample must also have:
- A fully-tested model unit for its plan (multi-orientation projects only)
- Been self-tested by the installer
- All mechanical CF-2R forms must be submitted and signed
Closed sample groups may have up to 7 dwellings. No CF-3Rs may be submitted for any dwellings during creation or editing of a closed sample group.
Open sample groups may have up to 5 dwellings. You can add (not remove) units from an open sample group until 5 dwellings are in the group or 180 days have passed since the first CF-2R signature was applied to any of the lots.
Alteration sample groups do not need models and cannot form open sample groups. Up to 7 systems can be in a sample group.