2018 IECC - Residential Provisions
The residential energy code applies to new construction as well as additions, alterations, renovations, and repairs.
Residential buildings include one- and two-family homes and townhouses of any size; apartments, boarding houses, dormitories, and other buildings with two or more permanent dwelling units; and residential care and assisted living facilities with three or fewer stories, among others.
Any unconditioned space that is altered to become conditioned space, such as heating an unfinished basement, must also fully comply with the code.
Residential Significant Changes with Idaho amendments
Maximum fenestration U-factor is 0.32 in CZ 5 and 0.30 in CZ 6
Minimum R-values increased
Duct insulation dependent on the location and diameter of the duct and building framing cavities may not be used as ducts or plenums
Minimum R-3 insulation required for select hot water piping applications and HVAC systems
At least 75% of permanently installed lighting fixtures must have high-efficacy lamps
Homes must be tested and verified as having 5 air changes per her (ACH) or fewer with exceptions
Maximum Energy Rating Index score of 68
Envelope Testing
Beginning July 1, 2021, envelope testing is required on at least 20% of all new single-family homes constructed by each builder.
Testing must follow RESNET/ICC Standard 380, ASTM E 779, or ASTM E 1827 protocols
Testers must be RESNET, BPI, or DET Certified. See upcoming training options for DET Certification
Corrective measures are required if the home has more than 5 air changes per hour
Compliance OPtions
Prescriptive
Total UA Alternative
Performance
Energy Rating Index
Required inspections
Footing and foundation
Framing and rough-in
Plumbing rough-in
Mechanical rough-in
Final