Do you use the zip code lookup in REM/Rate when assigning climate locations to your rated homes? If so, you may want to think twice. While the zip code lookup accurately assigns the closest location based on the first three digits of a homes zip code, it does not account for climate zone.
A home in Johnston County (CZ3) will almost certainly have a zip code starting with 275. Plug that into the location finder and what comes out?... Raleigh, which is in Wake County and is Climate Zone 4.
If the rated home is anywhere near a climate zone border (up to 2 counties away), be sure that the climate location lists the correct climate zone. This can have significant impacts on HERO compliance, as the reference home differs by CZ.