# Prescriptive Building Envelope Compliance Path ## Building Envelope Requirements These tables specify the maximum assembly U-factors, minimum insulation R-values, and other thermal requirements for building envelope components by climate zone and space conditioning category. These tables specify the maximum thermal performance requirements used to establish the baseline envelope in trade-off compliance calculations. The baseline design uses these maximum allowable values to create a reference against which the proposed design is compared. ### Climate Zone 0 (A,B) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-1.986 | NR | | Wood-framed and other | U-1.599 | NR | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Non-swinging | U-1.760 | — | **c.i.** = continuous insulation (see Section 3.2) **FC** = filled cavity (see Section A2.3.2.5) **Ls** = liner system (see Section A2.3.2.4) **NR** = no (insulation) requirement **\*** When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2). **\*\*** Exception to Section 5.5.3.2 applies for mass walls above grade (Climate Zones 0, 1, 2, 5, and 6 only). #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass\*\* | U-0.857 | R-1.0 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-1.986 | NR | | Wood-framed and other | U-1.599 | NR | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Non-swinging | U-1.760 | — | #### Opaque Elements - Semi-heated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-1.240 | R-0.7 c.i. | | Metal building | U-0.653 | R-1.8 | | Attic and other | U-0.459 | R-2.3 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-1.998 | NR | | Steel-framed | U-1.998 | NR | | Wood-framed and other | U-1.660 | NR | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-1.986 | NR | | Wood-framed and other | U-1.599 | NR | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-3.975 | — | | Non-swinging | U-8.233 | — | #### Fenestration - Climate Zone 0 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 2.84 | 0.22 | 1.10 | | | Operable | 3.52 | 0.20 | 1.10 | | | Entrance door | 4.71 | 0.20 | 1.10 | | **Residential** | Fixed | 2.84 | 0.22 | 1.10 | | | Operable | 3.52 | 0.20 | 1.10 | | | Entrance door | 4.71 | 0.20 | 1.10 | | **Semiheated** | Fixed | 2.84 | NR | NR | | | Operable | 3.69 | NR | NR | | | Entrance door | 6.25 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 3.97 | 0.30 | NR | | Residential | 3.97 | 0.30 | NR | | Semi-heated | 10.22 | NR | NR | *** ### Climate Zone 1 (A,B) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.273 | R-3.5 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-1.986 | NR | | Wood-framed and other | U-1.599 | NR | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Non-swinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass\*\* | U-0.857 | R-1.0 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-1.986 | NR | | Wood-framed and other | U-1.599 | NR | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Non-swinging | U-1.760 | — | #### Opaque Elements - Semiheated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-1.240 | R-0.7 c.i. | | Metal building | U-0.653 | R-1.8 | | Attic and other | U-0.459 | R-2.3 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-1.998 | NR | | Steel-framed | U-1.998 | NR | | Wood-framed and other | U-1.660 | NR | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-1.986 | NR | | Wood-framed and other | U-1.599 | NR | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-3.975 | — | | Non-swinging | U-8.233 | — | #### Fenestration - Climate Zone 1 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 2.84 | 0.23 | 1.10 | | | Operable | 3.52 | 0.21 | 1.10 | | | Entrance door | 4.71 | 0.21 | 1.10 | | **Residential** | Fixed | 2.84 | 0.23 | 1.10 | | | Operable | 3.52 | 0.21 | 1.10 | | | Entrance door | 4.71 | 0.21 | 1.10 | | **Semiheated** | Fixed | 6.81 | NR | NR | | | Operable | 6.81 | NR | NR | | | Entrance door | 6.25 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 3.97 | 0.30 | NR | | Residential | 3.97 | 0.30 | NR | | Semi-heated | 10.22 | NR | NR | *** ### Climate Zone 2 (A,B) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass\*\* | U-0.857 | R-1.0 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.479 | R-2.3 + R-0.7 c.i. | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.606 | R-1.9 | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.558 | R-1.8 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Non-swinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass | U-0.701 | R-1.3 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.365 | R-2.3 + R-1.3 c.i. | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.496 | R-1.5 | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.489 | R-2.6 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semi-heated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.982 | R-0.9 c.i. | | Metal building | U-0.545 | R-2.8 | | Attic and other | U-0.300 | R-3.3 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-0.920 | R-2.3 | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-1.825 | NR | | Steel joist | U-0.390 | R-2.3 | | Wood-framed and other | U-0.376 | R-2.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-3.975 | — | | Non-swinging | U-8.233 | — | #### Fenestration - Climate Zone 2 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 2.56 | 0.25 | 1.10 | | | Operable | 3.41 | 0.23 | 1.10 | | | Entrance door | 4.37 | 0.23 | 1.10 | | **Residential** | Fixed | 2.56 | 0.25 | 1.10 | | | Operable | 3.41 | 0.23 | 1.10 | | | Entrance door | 4.37 | 0.23 | 1.10 | | **Semiheated** | Fixed | 2.84 | NR | NR | | | Operable | 3.69 | NR | NR | | | Entrance door | 4.37 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 3.69 | 0.30 | NR | | Residential | 3.69 | 0.30 | NR | | Semi-heated | 5.11 | NR | NR | *** ### Climate Zone 3 (A,B,C) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass | U-0.701 | R-1.3 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.435 | R-2.3 + R-0.9 c.i. | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.420 | R-1.8 c.i. | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.489 | R-2.6 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Non-swinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | --------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building\* | U-0.233 | R-1.8 + R-3.3 FC | | Attic and other | U-0.153 | R-6.7 | | **Walls, Above Grade** | | | | Mass | U-0.592 | R-1.7 c.i. | | Metal building | U-0.410 | R-0 + R-2.3 c.i. | | Steel-framed | U-0.365 | R-2.3 + R-1.3 c.i. | | Wood-framed and other | U-0.365 | R-2.3 + R-0.7 c.i. or R-3.5 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.420 | R-1.8 c.i. | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.935 | R-1.8 for 600 mm | | Heated | F-1.489 | R-2.6 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semiheated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.677 | R-1.3 c.i. | | Metal building | U-0.545 | R-2.8 | | Attic and other | U-0.300 | R-3.3 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-0.920 | R-2.3 | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.780 | R-0.7 c.i. | | Steel joist | U-0.296 | R-3.3 | | Wood-framed and other | U-0.288 | R-3.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.766 | R-1.3 for 300 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-2.044 | — | #### Fenestration - Climate Zone 3 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 2.38 | 0.25 | 1.10 | | | Operable | 3.07 | 0.23 | 1.10 | | | Entrance door | 3.86 | 0.23 | 1.10 | | **Residential** | Fixed | 2.38 | 0.25 | 1.10 | | | Operable | 3.07 | 0.23 | 1.10 | | | Entrance door | 3.86 | 0.23 | 1.10 | | **Semiheated** | Fixed | 2.84 | NR | NR | | | Operable | 3.69 | NR | NR | | | Entrance door | 4.37 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 3.12 | 0.30 | NR | | Residential | 3.12 | 0.30 | NR | | Semiheated | 5.11 | NR | NR | *** ### Climate Zone 4 (A,B,C) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ------------------------------------ | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.210 | R-3.3 + R-1.9 Ls or R-4.4 + R-1.4 Ls | | Attic and other | U-0.119 | R-8.6 | | **Walls, Above Grade** | | | | Mass | U-0.592 | R-1.7 c.i. | | Metal building | U-0.341 | R-0 + R-2.8 c.i. | | Steel-framed | U-0.365 | R-2.3 + R-1.3 c.i. | | Wood-framed and other | U-0.365 | R-2.3 + R-0.7 c.i. or R-3.5 | | **Wall, Below Grade** | | | | Below-grade wall | C-0.678 | R-1.3 c.i. | | **Floors** | | | | Mass | U-0.321 | R-2.6 c.i. | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.900 | R-2.6 for 600 mm | | Heated | F-1.459 | R-3.5 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ------------------------------------ | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.210 | R-3.3 + R-1.9 Ls or R-4.4 + R-1.4 Ls | | Attic and other | U-0.119 | R-8.6 | | **Walls, Above Grade** | | | | Mass | U-0.513 | R-2.0 c.i. | | Metal building | U-0.286 | R-0 + R-3.3 c.i. | | Steel-framed | U-0.365 | R-2.3 + R-1.3 c.i. | | Wood-framed and other | U-0.365 | R-2.3 + R-0.7 c.i. or R-3.5 | | **Wall, Below Grade** | | | | Below-grade wall | C-0.522 | R-1.8 c.i. | | **Floors** | | | | Mass | U-0.287 | R-2.9 c.i. | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.900 | R-2.6 for 600 mm | | Heated | F-1.191 | R-3.5 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semiheated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.527 | R-1.8 c.i. | | Metal building | U-0.466 | R-3.3 | | Attic and other | U-0.192 | R-5.3 | | **Walls, Above Grade** | | | | Mass | U-3.293 | NR | | Metal building | U-0.920 | R-2.3 | | Steel-framed | U-0.705 | R-2.3 | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.606 | R-1.1 c.i. | | Steel joist | U-0.296 | R-3.3 | | Wood-framed and other | U-0.288 | R-3.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.558 | R-1.8 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-2.044 | — | #### Fenestration - Climate Zone 4 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 2.04 | 0.36 | 1.10 | | | Operable | 2.56 | 0.33 | 1.10 | | | Entrance door | 3.58 | 0.33 | 1.10 | | **Residential** | Fixed | 2.04 | 0.36 | 1.10 | | | Operable | 2.56 | 0.33 | 1.10 | | | Entrance door | 3.58 | 0.33 | 1.10 | | **Semiheated** | Fixed | 2.84 | NR | NR | | | Operable | 3.69 | NR | NR | | | Entrance door | 4.37 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 2.84 | 0.40 | NR | | Residential | 2.84 | 0.40 | NR | | Semiheated | 4.26 | NR | NR | *** ### Climate Zone 5 (A,B,C) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ---------------------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.210 | R-3.3 + R-1.9 Ls or R-4.4 + R-1.4 Ls | | Attic and other | U-0.119 | R-8.6 | | **Walls, Above Grade** | | | | Mass | U-0.513 | R-2.0 c.i. | | Metal building | U-0.286 | R-0 + R-3.3 c.i. | | Steel-framed | U-0.315 | R-2.3 + R-1.8 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-0.9 c.i. or R-3.3 + R-0.9 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.678 | R-1.3 c.i. | | **Floors** | | | | Mass | U-0.321 | R-2.6 c.i. | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.900 | R-2.6 for 600 mm | | Heated | F-1.191 | R-3.5 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ---------------------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.210 | R-3.3 + R-1.9 Ls or R-4.4 + R-1.4 Ls | | Attic and other | U-0.119 | R-8.6 | | **Walls, Above Grade** | | | | Mass | U-0.453 | R-2.3 c.i. | | Metal building | U-0.286 | R-0 + R-3.3 c.i. | | Steel-framed | U-0.315 | R-2.3 + R-1.8 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-0.9 c.i. or R-3.3 + R-0.9 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.522 | R-1.8 c.i. | | **Floors** | | | | Mass | U-0.287 | R-2.9 c.i. | | Steel joist | U-0.214 | R-5.3 | | Wood-framed and other | U-0.188 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.882 | R-3.5 for 600 mm | | Heated | F-1.191 | R-3.5 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semiheated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.360 | R-2.6 c.i. | | Metal building | U-0.466 | R-3.3 | | Attic and other | U-0.192 | R-5.3 | | **Walls, Above Grade** | | | | Mass\*\* | U-0.857 | R-1.0 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.479 | R-2.3 + R-0.7 c.i. | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-6.473 | NR | | **Floors** | | | | Mass | U-0.606 | R-1.1 c.i. | | Steel joist | U-0.296 | R-3.3 | | Wood-framed and other | U-0.288 | R-3.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.558 | R-1.8 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-2.044 | — | #### Fenestration - Climate Zone 5 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 2.04 | 0.38 | 1.10 | | | Operable | 2.56 | 0.33 | 1.10 | | | Entrance door | 3.58 | 0.33 | 1.10 | | **Residential** | Fixed | 2.04 | 0.38 | 1.10 | | | Operable | 2.56 | 0.33 | 1.10 | | | Entrance door | 3.58 | 0.33 | 1.10 | | **Semiheated** | Fixed | 2.84 | NR | NR | | | Operable | 3.69 | NR | NR | | | Entrance door | 4.37 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 2.84 | 0.40 | NR | | Residential | 2.84 | 0.40 | NR | | Semiheated | 4.26 | NR | NR | *** ### Climate Zone 6 (A,B) #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ---------------------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.175 | R-4.4 + R-1.9 Ls | | Attic and other | U-0.119 | R-8.6 | | **Walls, Above Grade** | | | | Mass | U-0.453 | R-2.3 c.i. | | Metal building | U-0.286 | R-0 + R-3.3 c.i. | | Steel-framed | U-0.277 | R-2.3 + R-2.2 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-1.3 c.i. or R-3.3 + R-0.9 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.522 | R-1.8 c.i. | | **Floors** | | | | Mass | U-0.287 | R-2.9 c.i. | | Steel joist | U-0.183 | R-6.7 | | Wood-framed and other | U-0.153 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.882 | R-3.5 for 600 mm | | Heated | F-1.191 | R-3.5 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ---------------------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.184 | R-5.3 c.i. | | Metal building\* | U-0.163 | R-5.3 + R-1.9 Ls | | Attic and other | U-0.119 | R-8.6 | | **Walls, Above Grade** | | | | Mass | U-0.404 | R-2.7 c.i. | | Metal building | U-0.286 | R-0 + R-3.3 c.i. | | Steel-framed | U-0.277 | R-2.3 + R-2.2 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-1.3 c.i. or R-3.3 + R-0.9 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.358 | R-2.6 c.i. | | **Floors** | | | | Mass | U-0.287 | R-2.9 c.i. | | Steel joist | U-0.183 | R-6.7 | | Wood-framed and other | U-0.153 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.750 | R-3.5 for 1200 mm | | Heated | F-1.162 | R-4.4 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semiheated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.360 | R-2.6 c.i. | | Metal building | U-0.341 | R-3.3 + R-3.3 | | Attic and other | U-0.192 | R-5.3 | | **Walls, Above Grade** | | | | Mass\*\* | U-0.857 | R-1.0 c.i. | | Metal building | U-0.533 | R-0 + R-1.7 c.i. | | Steel-framed | U-0.479 | R-2.3 + R-0.7 c.i. | | Wood-framed and other | U-0.504 | R-2.3 | | **Wall, Below Grade** | | | | Below-grade wall | C-0.678 | R-1.3 c.i. | | **Floors** | | | | Mass | U-0.496 | R-1.5 c.i. | | Steel joist | U-0.296 | R-3.3 | | Wood-framed and other | U-0.288 | R-3.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.489 | R-2.6 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-2.044 | — | #### Fenestration - Climate Zone 6 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 1.93 | 0.38 | 1.10 | | | Operable | 2.38 | 0.34 | 1.10 | | | Entrance door | 3.58 | 0.34 | 1.10 | | **Residential** | Fixed | 1.93 | 0.38 | 1.10 | | | Operable | 2.38 | 0.34 | 1.10 | | | Entrance door | 3.58 | 0.34 | 1.10 | | **Semiheated** | Fixed | 2.21 | NR | NR | | | Operable | 2.73 | NR | NR | | | Entrance door | 3.86 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 2.67 | 0.40 | NR | | Residential | 2.84 | 0.40 | NR | | Semiheated | 4.26 | NR | NR | *** ### Climate Zone 7 #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ---------------------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.158 | R-6.2 c.i. | | Metal building\* | U-0.163 | R-5.3 + R-1.9 Ls | | Attic and other | U-0.098 | R-10.6 | | **Walls, Above Grade** | | | | Mass | U-0.404 | R-2.7 c.i. | | Metal building | U-0.248 | R-0 + R-3.9 c.i. | | Steel-framed | U-0.277 | R-2.3 + R-2.2 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-1.3 c.i. or R-3.3 + R-0.9 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.358 | R-2.6 c.i. | | **Floors** | | | | Mass | U-0.236 | R-3.7 c.i. | | Steel joist | U-0.183 | R-6.7 | | Wood-framed and other | U-0.153 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.882 | R-3.5 for 600 mm | | Heated | F-1.162 | R-4.4 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ---------------------------------------- | | **Roofs** | | | | Insulation entirely above deck | U-0.158 | R-6.2 c.i. | | Metal building\* | U-0.163 | R-5.3 + R-1.9 Ls | | Attic and other | U-0.098 | R-10.6 | | **Walls, Above Grade** | | | | Mass | U-0.404 | R-2.7 c.i. | | Metal building | U-0.248 | R-0 + R-3.9 c.i. | | Steel-framed | U-0.240 | R-2.3 + R-2.7 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-1.3 c.i. or R-3.3 + R-0.9 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.358 | R-2.6 c.i. | | **Floors** | | | | Mass | U-0.236 | R-3.7 c.i. | | Steel joist | U-0.183 | R-6.7 | | Wood-framed and other | U-0.153 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.750 | R-3.5 for 1200 mm | | Heated | F-1.162 | R-4.4 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semiheated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ------------------------------------ | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building | U-0.210 | R-3.3 + R-1.9 Ls or R-4.4 + R-1.4 Ls | | Attic and other | U-0.153 | R-6.7 c.i. | | **Walls, Above Grade** | | | | Mass | U-0.701 | R-1.3 c.i. | | Metal building | U-0.410 | R-0 + R-2.3 c.i. | | Steel-framed | U-0.365 | R-2.3 + R-1.3 c.i. | | Wood-framed and other | U-0.365 | R-2.3 + R-0.7 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.678 | R-1.3 c.i. | | **Floors** | | | | Mass | U-0.420 | R-1.8 c.i. | | Steel joist | U-0.296 | R-3.3 | | Wood-framed and other | U-0.288 | R-3.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-1.264 | NR | | Heated | F-1.489 | R-2.6 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Fenestration - Climate Zone 7 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 1.65 | 0.40 | 1.10 | | | Operable | 2.04 | 0.36 | 1.10 | | | Entrance door | 3.58 | 0.36 | 1.10 | | **Residential** | Fixed | 1.65 | 0.40 | 1.10 | | | Operable | 2.04 | 0.36 | 1.10 | | | Entrance door | 3.58 | 0.36 | 1.10 | | **Semiheated** | Fixed | 2.04 | NR | NR | | | Operable | 2.50 | NR | NR | | | Entrance door | 3.58 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 2.50 | NR | NR | | Residential | 2.50 | NR | NR | | Semiheated | 4.26 | NR | NR | *** ### Climate Zone 8 #### Opaque Elements - Nonresidential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ------------------------ | | **Roofs** | | | | Insulation entirely above deck | U-0.158 | R-6.2 c.i. | | Metal building\* | U-0.147 | R-4.4 + R-1.9 + R-1.9 Ls | | Attic and other | U-0.098 | R-10.6 | | **Walls, Above Grade** | | | | Mass | U-0.273 | R-3.3 c.i. | | Metal building | U-0.220 | R-0 + R-4.4 c.i. | | Steel-framed | U-0.212 | R-2.3 + R-3.3 c.i. | | Wood-framed and other | U-0.182 | R-2.3 + R-3.3 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.358 | R-2.6 c.i. | | **Floors** | | | | Mass | U-0.217 | R-4.1 c.i. | | Steel joist | U-0.183 | R-6.7 | | Wood-framed and other | U-0.153 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.750 | R-3.5 for 1200 mm | | Heated | F-1.162 | R-4.4 for 1200 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Residential | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ------------------------ | | **Roofs** | | | | Insulation entirely above deck | U-0.158 | R-6.2 c.i. | | Metal building\* | U-0.147 | R-4.4 + R-1.9 + R-1.9 Ls | | Attic and other | U-0.098 | R-10.6 | | **Walls, Above Grade** | | | | Mass | U-0.273 | R-3.3 c.i. | | Metal building | U-0.220 | R-0 + R-4.4 c.i. | | Steel-framed | U-0.212 | R-2.3 + R-3.3 c.i. | | Wood-framed and other | U-0.182 | R-2.3 + R-3.3 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.358 | R-2.6 c.i. | | **Floors** | | | | Mass | U-0.217 | R-4.1 c.i. | | Steel joist | U-0.183 | R-6.7 | | Wood-framed and other | U-0.153 | R-6.7 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.734 | R-4.4 for 1200 mm | | Heated | F-0.646 | R-3.5 full slab | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Opaque Elements - Semi-heated | Element | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ------------------------------------ | | **Roofs** | | | | Insulation entirely above deck | U-0.220 | R-4.4 c.i. | | Metal building | U-0.210 | R-3.3 + R-1.9 Ls or R-4.4 + R-1.4 Ls | | Attic and other | U-0.153 | R-6.7 c.i. | | **Walls, Above Grade** | | | | Mass | U-0.592 | R-1.7 c.i. | | Metal building | U-0.341 | R-0 + R-2.8 c.i. | | Steel-framed | U-0.365 | R-2.3 + R-1.3 c.i. | | Wood-framed and other | U-0.291 | R-2.3 + R-1.3 c.i. | | **Wall, Below Grade** | | | | Below-grade wall | C-0.678 | R-1.3 c.i. | | **Floors** | | | | Mass | U-0.363 | R-2.2 c.i. | | Steel joist | U-0.296 | R-3.3 | | Wood-framed and other | U-0.188 | R-5.3 | | **Slab-on-Grade Floors** | | | | Unheated | F-0.935 | R-1.8 for 600 mm | | Heated | F-1.489 | R-2.6 for 600 mm | | **Opaque Doors** | | | | Swinging | U-2.101 | — | | Nonswinging | U-1.760 | — | #### Fenestration - Climate Zone 8 **Vertical Fenestration (0% to 40% of Wall)** | Space Type | Fenestration Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | ------------------ | ----------------- | --------------- | ------------------ | --------------------- | | **Nonresidential** | Fixed | 1.48 | 0.40 | 1.10 | | | Operable | 1.82 | 0.36 | 1.10 | | | Entrance door | 3.58 | 0.36 | 1.10 | | **Residential** | Fixed | 1.48 | 0.40 | 1.10 | | | Operable | 1.82 | 0.36 | 1.10 | | | Entrance door | 3.58 | 0.36 | 1.10 | | **Semiheated** | Fixed | 2.04 | NR | NR | | | Operable | 2.50 | NR | NR | | | Entrance door | 3.58 | NR | NR | **Skylights (0% to 3% of Roof)** | Space Type | Assembly Max. U | Assembly Max. SHGC | Assembly Min. VT/SHGC | | -------------- | --------------- | ------------------ | --------------------- | | Nonresidential | 2.33 | NR | NR | | Residential | 2.33 | NR | NR | | Semiheated | 4.26 | NR | NR | ## Roof Insulation All roofs shall comply with the insulation values specified above. Skylight curbs shall be insulated to the level of roofs with insulation entirely above deck or R-0.9, whichever is less. ### Roof Solar Reflectance and Thermal Emittance Roofs in Climate Zones 0 through 3 shall have one of the following: #### Option a: Minimum Aged Reflectance and Emittance A minimum three-year-aged solar reflectance of 0.55 and a minimum three-year-aged thermal emittance of 0.75 when tested in accordance with CRRC S100. #### Option b: Minimum Solar Reflectance Index A minimum Solar Reflectance Index of 64 when determined in accordance with the Solar Reflectance Index method in ASTM E1980 using a convection coefficient of 12 W/m²·K, based on three-year-aged solar reflectance and three-year-aged thermal emittance tested in accordance with CRRC S100. #### Option c: Increased Insulation Increased roof insulation levels found below. #### Climate Zone 0 #### Nonresidential | Roof Type | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | Insulation entirely above deck | U-0.153 | R-6.4 c.i. | | Metal buildings | U-0.159 | R-6.2 | #### Residential | Roof Type | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | Insulation entirely above deck | U-0.153 | R-6.4 c.i. | #### Climate Zones 1 to 3 #### Nonresidential | Roof Type | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | Insulation entirely above deck | U-0.170 | R-5.8 c.i. | | Metal buildings | U-0.159 | R-6.2 | #### Residential | Roof Type | Assembly Maximum | Insulation Min. R-Value | | ------------------------------ | ---------------- | ----------------------- | | Insulation entirely above deck | U-0.165 | R-6.0 c.i. | #### Exceptions The following roof types are exempt from the solar reflectance and thermal emittance requirements:
ExceptionDescription
1. Ballasted RoofsBallasted roofs with a minimum stone ballast of 83 kg/m² or 112 kg/m² pavers
2. Vegetative RoofsVegetative roof systems that contain a minimum thickness of 64 mm of growing medium and covering a minimum of 75% of the roof area with durable plantings
3. Shaded/Covered RoofsRoofs where a minimum of 75% of the roof area:<br>a. Is shaded during the peak sun angle on June 21 by permanent components or features of the building<br>b. Is covered by offset photovoltaic arrays, building-integrated photovoltaic arrays, or solar air or water collectors<br>c. Is permitted to be interpolated using a combination of (a) and (b) above
4. Steep-Sloped RoofsSteep-sloped roofs
5. Metal Building RoofsLow-sloped metal building roofs in Climate Zones 2 and 3
6. Uncooled SpacesRoofs over ventilated attics, roofs over semi-heated spaces, or roofs over conditioned spaces that are not cooled spaces
7. Asphaltic MembranesAsphaltic membranes in Climate Zones 2 and 3
{% hint style="success" %} These requirements establish minimum solar reflectance and thermal emittance standards for roofs in hot climates (Climate Zones 0-3) to reduce cooling loads from solar heat gain. The exceptions recognize roof types that inherently have reduced solar heat gain through other means (ballast, vegetation, shading) or where cooling loads are not a concern (uncooled spaces). For baseline modeling, roofs meeting these requirements use the specified reflectance and emittance values, while exempt roofs are modeled as proposed. {% endhint %} ## Fenestration ### General Compliance with U-factors, SHGC, and VT/SHGC shall be demonstrated for the overall fenestration product. Gross wall areas and gross roof areas shall be calculated separately for each space conditioning category for the purposes of determining compliance. **Exception 1: Area-Weighted Average Within Single Class** If there are multiple assemblies within a single class of construction for a single space conditioning category, it shall be permitted to demonstrate compliance based on an area-weighted average U-factor, SHGC, VT/SHGC, or LSG. The area-weighted average across multiple classes of construction or multiple space conditioning categories shall not be permitted for use to demonstrate compliance. **Exception 2: Area-Weighted Average for Vertical Fenestration Across Classes** Vertical fenestration shall be permitted to demonstrate compliance based on an area-weighted average U-factor, SHGC, VT/SHGC, or LSG across multiple classes of construction for a single space conditioning category, but not across multiple space conditioning categories. ### Fenestration Area #### Vertical Fenestration Area The total vertical fenestration area shall not be greater than that specified in the tables above. #### Exception 3: Street-Level Fenestration Vertical fenestration that is located on the street side of the street-level story only, provided that all of the following criteria are met: | Criterion | Requirement | | ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Height Limit** | The street side of the street-level story does not exceed 6 m in height | | **Shading** | The fenestration has a continuous overhang with a weighted average PF greater than 0.5 | | **Area Limit** | The fenestration area for the street side of the street-level story is less than 75% of the gross wall area for the street side of the street-level story | **Calculation Requirements:** When this exception is used, separate calculations shall be performed for these sections of the building envelope, and these values shall not be averaged with any others for compliance purposes. No credit shall be given here or elsewhere in the building for not fully utilizing the fenestration area allowed. ### Modeling Intent This exception accommodates the unique needs of street-level retail and commercial spaces that require extensive glazing for visibility and access while maintaining energy performance through height limits, mandatory shading, and area restrictions. The separate calculation requirement prevents this exception from being used to circumvent fenestration limits for other portions of the building. #### Maximum Skylight Fenestration Area The total skylight area shall not be greater than that specified in the tables above. **Exception** The total skylight area is permitted to be increased to no greater than 6% of the gross roof area, provided the skylights meet all of the criteria in Exception 1 below and the total daylight area under skylights is a minimum of half the floor area of the space. #### Exception 1: High-Diffusing Skylights with Photocontrols Skylights are exempt from SHGC requirements provided the following criteria are met: | Criterion | Requirement | | ---------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- | | **a. Haze Value** | Glazing material or diffuser with a measured haze value greater than 90% when tested according to ASTM D1003 | | **b. Visible Transmittance** | Skylight VT greater than 0.40 | | **c. Lighting Controls** | All general lighting in the daylight area under skylights controlled by multilevel photocontrols in accordance with Section 9.4.1.1(f) | #### Exception 2: Dynamic Glazing For dynamic glazing, the minimum SHGC shall be used to demonstrate compliance with this section. Dynamic glazing shall be considered separately from other skylights, and area-weighted averaging with other skylights that are not dynamic glazing shall not be permitted. {% hint style="success" %} These requirements establish maximum fenestration-to-wall and fenestration-to-roof area ratios (typically 40% for walls and 3% for roofs as shown in Tables 5.5-0 through 5.5-8) while requiring fenestration products to meet thermal and solar performance criteria. The exceptions allow flexibility for area-weighted averaging within defined boundaries and for increased skylight area when enhanced daylighting performance is achieved. In baseline modeling, fenestration area is reduced proportionally if the proposed design exceeds these limits, ensuring fair comparison of envelope performance. {% endhint %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.betterbuilding.io/user-guide/workflows/energy-efficiency/ashrae-90.1-2019/appendix-c-methodology-for-building-envelope-trade-off-option/prescriptive-building-envelope-compliance-path.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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