Measure Name | Measure Description |
Air Sealing
| Reduce infiltration by 40 percent to 3 ACH50. |
Window U-factor | Reduce window U-factor to 0.24. |
Window SHGC | Increase solar heat gain coefficient (SHGC) to 0.50 in climate zones where heating loads dominate. |
Cool Roof
| Install a roofing product that has an aged solar reflectance (ASR) equal to or greater than 0.25. Steep-sloped roofs were assumed in all cases. |
Attic Insulation
| Increase insulation in a vented attic to R-49 or R-60 insulation. |
Slab Edge Insulation | Install R-10 perimeter slab insulation at a depth of 16-inches. Exclusion: Climate Zone 16 |
Low Pressure Drop Ducts
| Upgrade the duct distribution system to reduce external static pressure and meet a maximum fan efficacy of 0.35 Watts per cfm. This may involve upsizing ductwork, reducing the total effective length of ducts, and/or selecting low pressure drop components such as filters. Must be verified by a HERS rater. |
Buried Ducts | Bury all ductwork in ceiling insulation by laying the ducts across the ceiling joists or in between ceiling joists directly on the ceiling drywall. Duct design is based on a radial design where individual ducts are run to each supply register. Must be verified by a HERS rater. Exclusion: ADUs. |
R-8 Duct Insulation
| Increase duct insulation to R-8 |
Ductless Mini Split Heat Pump
| Replace the ducted split system with a ductless mini-split heat pump with three indoor heads. Must be verified by a HERS rater. This credit requires verification of refrigerant charge, that all equipment is entirely within conditioned space, that airflow is directly supplied to all habitable space and that wall mounted thermostats serve any zones greater than 150 square feet. Exclusion: Single Family Units |
Compact Hot Water Distribution | Design the hot water distribution system to meet minimum requirements for the basic compact hot water distribution credit according to the procedures outlined in the 2022 Reference Appendices RA4.4.6, which is assumed to result in a 30% reduction in distribution losses. In many single family homes this may require moving the water heater from an exterior to an interior garage wall. |