Code of Massachusetts Regulations
780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS
Chapter CHAPTER 51 - MASSACHUSETTS RESIDENTIAL CODE
Chapter 4 - [RE] RESIDENTIAL ENERGY EFFICIENCY
Section R408 - ADDITIONAL EFFICIENCY PACKAGE OPTIONS
Subsection R408.2 - Additional efficiency package options.
Current through Register 1543, March 14, 2025
Additional efficiency package options for compliance with Section R401.2.1 are set forth in Sections R408.2.1 through R408.2.5.
R408.2.1 Enhanced envelope performance option. The total building thermal envelope UA, the sum of U-factor times assembly area, shall be less than or equal to 95 percent of the total UA resulting from multiplying the U-factors in Table R402.1.2 by the same assembly area as in the proposed building. The UA calculation shall be performed in accordance with Section R402.1.5. The area-weighted average SHGC of all glazed fenestration shall be less than or equal to 95 percent of the maximum glazed fenestration SHGC in Table R402.1.2.
R408.2.2 More efficient HVAC equipment performance option. Heating and cooling equipment shall meet one of the following efficiencies:
For multiple cooling systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the cooling design load. For multiple heating systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the heating design load.
R408.2.3 Reduced energy use in service water-heating option. The hot water system shall meet one of the following efficiencies:
R408.2.4 More efficient duct thermal distribution system option. The thermal distribution system shall meet one of the following efficiencies: