402 BUILDING ENVELOPE REQUIREMENTS

C402.1.2 Equipment buildings. Buildings that comply with the following shall be exempt from the building thermal envelope provisions of this code: 1. Are separate buildings with floor area not more than 500 square feet (50 m2). 2. Are intended to house electronic equipment with installed equipment power totaling not less than 7 watts per square foot (75 W/m2) and not intended for human occupancy. 3. Have an average wall and roof U-factor less than 0.200 in Climate Zone 15. Comply with the roof solar reflectance and thermal emittance provisions for Climate Zone 1. C402.1.3 Insulation component R- value-based method. Building thermal envelope opaque assemblies shall comply with the requirements of Sections C402.2 and C402.4 based on the climate zone specified in Chapter 3. For opaque portions of the building thermal envelope intended to comply on an insulation component R-value basis, the R-values for insulation shall be not less than that specified in Table C402.1.3. Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the R-values from the "Group 779 R" column of Table C402.1.3. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the R-values from the "All other" column of Table C402.1.3. 780 TABLE C402.1.3 OPAQUE THERMAL ENVELOPE INSULATION COMPONENT MINIMUM REQUIREMENTS, R-VALUE METHOD a,i CLIMATE ZONE All Roofs Insulation entirely above roof deck R-20ci Metal Buildingsᵇ R-20 Attic and other R-38 Walls, above grade Massᵍ NR Metal Building R-13 Metal framed R-13 Wood framed and other R-13 Walls, below grade Below-grade walld NR Floors Massᵉ NR Joist/framing NR Slab-on-grade floors Unheated slabs NR Opaque doors Nonswinging U-1.54 For SI: 1 inch = 25.4 mm, 1 pound per square foot = 4.88 kg/m², 1 pound per cubic foot = 16 kg/m³. ci = Continuous insulation, NR = No Requirement, LS = Liner System. a. Assembly descriptions can be found in ANSI/ASHRAE/IESNA Appendix A. b. Where usingR-value compliance method, a thermal spacer block shall be provided, otherwise use the U-factor compliance method in Table C402.1.4. c. R-5.7ci is allowed to be substituted with concrete block walls complying with ASTM C90, ungrouted or partially grouted at 32 inches or less on center vertically and 48 inches or less on center horizontally, with ungrouted cores filled with materials having a maximum thermal conductivity of 0.44 Btu-in/h-f2 °F. d. Where heated slabs are below grade, below-grade walls shall comply with the exterior insulation requirements for heated slabs. e. "Mass floors" shall be in accordance with Section C402.2.3. f. Steel floor joist systems shall be insulated to R-38. g. "Mass walls" shall be in accordance with Section C402.2.2. h. The first value is for perimeter insulation and the second value is for slab insulation. Perimeter insulation is not required to extend below the bottom of the slab. i. Not applicable to garage doors. See Table C402.1.4 781 Table C402.1.4 OPAQUE THERMAL ENVELOPE ASSEMBLY MAXIMUM REQUIREMENTS, U- FACTOR METHOD a,b CLIMATE ZONE All other Roofs Insulation entirely above roof deck U-0.048 Metal Buildings U-0.048 Walls, Above Grade Massᵍ NR Metal Building U-0.078 Metal framed U-0.078 Wood framed and other U-0.078 Walls, below grade Below-grade wallᶜ NR Floors Massᵉ NR Joist/framing NR Slab-on-grade floors Unheated slabs NR Opaque doors Swinging door U-1.45 Garage door <14% U-1.45 For SI: 1 pound per square foot = 4.88 kg/m², 1 pound per cubic foot = 16 kg/m³. ci = Continuous insulation, NR = No Requirement, LS = Liner System. a. Where assembly U-factors, C-factors, and F-factors are established in ANSI/ASHRAE/IESNA 90.1 Appendix A, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table, and provided that the construction, excluding the cladding system on walls, complies with the appropriate construction details from ANSI/ASHRAE/ISNEA 90.1 Appendix A. b. Where U-factors have been established by testing in accordance with ASTM C1363, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table. The R-value of continuous insulation shall be permitted to be added to or subtracted from the original tested design. c. Where heated slabs are below grade, below-grade walls shall comply with the U-factor requirements for above-grade mass walls. d. "Mass floors" shall be in accordance with Section C402.2.3. e. These C-, F- and U-factors are based on assemblies that are not required to contain insulation. f. The first value is for perimeter insulation and the second value is for full slab insulation. g. "Mass walls" shall be in accordance with Section C402.2.2. 782 C402.1.4 Assembly U- factor, C -factor or F -factor based-method. Building thermal envelope opaque assemblies shall meet the requirements of Sections C402.2 and C402.4 based on the climate zone specified in Chapter 3. Building thermal envelope opaque assemblies intended to comply on an assembly U-, C- or F-factor basis shall have a U-, C- or F-factor not greater than that specified in Table C402.1.4. Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the U-, C- or F-factor from the "Group R" column of Table C402.1.4. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the U-, C- or F-factor from the "All other" column of Table C402.1.4 C402.4 Fenestration (Prescriptive). Fenestration shall comply with Sections C402.4.1 through C402.4.5 and Table C402.4. Daylight responsive controls shall comply with this section and Section C405.2.3.1. C402.4.1 Maximum area. The vertical fenestration area, not including opaque doors and opaque spandrel panels, shall be not greater than 80 percent of the gross above-grade wall area. The skylight area shall be not greater than 10 percent of the gross roof area. C402.4.1.1 Increased vertical fenestration area with daylight responsive controls. In Climate Zones 1, , not more than 90 percent of the gross above-grade wall area shall be vertical fenestration, provided that all of the following requirements are met. TABLE C402.4 BUILDING ENVELOPE FENESTRATION MAXIMUM U-FACTOR AND SHGC REQUIREMENTS CLIMATE ZONE 1 Vertical fenestration U-factor Fixed fenestration 1.2 Operable fenestration 1.2 Entrance doors 1.2 SHGC Orientation SEW N PF < 0.2 0.25 0.33 0.2 <OF < 0.5 0.30 0.37 PF ≥0.5 0.40 0.40 Skylights U-factor 0.75 SHGC 0.35 783 C402.4.2 Minimum skylight fenestration area. Exception: Skylights above daylight zones of enclosed spaces are not required in: 1. Spaces where the designed general lighting power densities are less than 0.5 W/ft2 (5.4 W/m2). 2. Areas where it is documented that existing structures or natural objects block direct beam sunlight on not less than half of the roof over the enclosed area for more than 1,500 daytime hours per year between 8 a.m. and 4 p.m. 3. Spaces where the daylight zone under rooftop monitor is greater than 50 percent of the enclosed space floor area. 4. Spaces where the total area minus the area of sidelight daylight zone is less than 2,500 square feet (232 m2), and where the lighting is controlled in accordance with Section C405.2.3. C402.4.3 Maximum U- factor and SHGC. C402.4.3.1 Increased skylight SHGC. In Climate Zones 1 skylights shall be permitted a maximum SHGC of 0.60 where located above daylight zones provided with daylight responsive controls. C402.4.3.2 Increased skylight U- factor. Where skylights are installed above daylight zones provided with daylight responsive controls, a maximum U-factor of 0.9 shall be permitted in Climate Zones 1 C402.5 Air leakage - thermal envelope(Mandatory) - Deleted C402.5.1- C402.5.5 - Deleted C402.5.6 Loading dock weather-seals at air conditioner spaces. Cargo door openings and loading door openings shall be equipped with weather-seals that restrict infiltration and provide direct contact along the top and sides of vehicles that are parked in the doorway. C402.5.7 Vestibules. Building entrances shall be protected with self-closing devices. 784