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Hawaii County Energy Code Bill Annotated Draft 11127119 to the farthest most point of the overhang divided by the vertical distance from the first floor level to the bottom most point of the overhang 3. Concrete, CMU, and similar mass walls are 6 inches or greater in thickness. The R-value of integral insulation installed in concrete masonry units shall not be used in determining compliance with Table C402.1.3. "Mass walls" shall include walls: 1. Weighing not less than 35 psf(170 kg/m ) of wall surface area. 2. Weighing not less than 25 psf(120 kg/m2) of wall surface area where the material weight is not more than 120 pcf(1900 kg/m 3). 3. Having a heat capacity exceeding 7 Btu/ft2• OF (144 kJ/m2• K). 4. Having a heat capacity exceeding 5 Btufft2• OF (103 kJ/m2• K), where the material weight is not more than 120 pcf(1900 kg/M3).,, Comments: A. State Justification: Modeling analysis shows that R-13 is the most impactful level of insulation for buildings and that removing continuous insulation on steel frame walls does not significantly impact whole building energy use. Adding shading to the wall system with a projection factor of at least 0.3 eliminates the need for continuous insulation in exterior wall systems resulting in an energy equivalent installation. In a tropical climate, the impact of wall insulation is diminished for commercial buildings with more importance placed on roof insulation and window solar heat gain coefficient(SHGC). Envelope trade-offs for residential construction can be extrapolated to commercial construction for wall systems allowing the trade-off for a projection factor on wall systems to work for both residential and commercial buildings. Adding reflective coatings on wall systems is also an effective trade-off for continuous insulation in residential exterior wall systems. As with the projection factor, this trade-off can be transferred to commercial buildings as an energy neutral trade-off A reflective coating trade-off for continuous insulation is appropriate for commercial wall systems by providing an energy neutral trade-off The full analysis is contained in the "Analyses and proposal of Hawai`i amendments to the 2015 International Energy Conservation Code, " dated May 2016 See: State ECC at§3-181.1-9, HAR. B. Maui County Justification:Additionally, exception 3 will reduce the footprint of the structure when using mass wall, which will reduce construction costs. See: §16.1613.C402.2.3, MCC. C. Kauai County also incorporated change at§12-6.4(13), KCC. 10