Heads up: There are no amended sections in this chapter.
Section 5 specifies requirements for the building envelope.
Separate exterior building envelope requirements are specified for each of three categories of conditioned space: (a) nonresidential conditioned space, (b) residential conditioned space, and (c) semiheated space.
The minimum skylight area requirements in Section 5.5.4.2.3 are also specified for unconditioned spaces.
Spaces shall be assumed to be conditioned spaces and shall comply with the requirements for conditioned spaces at the time of construction, regardless of whether mechanical or electrical equipment is included in the building permit application or installed at that time.
In Climate Zones 3 through 8, a space may be designated as either a semiheated space or an unconditioned space only if approved by the building official.

5.1.3 Envelope Alterations

AMENDMENT
This section has been amended at the state or city level.
Alterations to the building envelope shall comply with the requirements of Section 5 for insulation, air leakage, and fenestration applicable to those specific portions of the building that are being altered.

Exceptions:

  1. Installation of storm windows or glazing panels over existing glazing, provided the storm window or glazing panel contains a low-emissivity coating. However, a low-emissivity coating is not required where the existing glazing already has a low-emissivity coating. Installation may be either on the inside or outside of the existing glazing.
  2. Replacement of glazing in existing sash and frame, provided the U-factor and SHGC will be equal to or lower than before the glass replacement.
  3. Alterations to roof or ceiling, wall, or floor cavities that are insulated to full depth with insulation having a minimum nominal value of R-3.0/in.
  4. Alterations to walls and floors, where the existing structure is without framing cavities and no new framing cavities are created.
  5. Roof recovering.
  6. Removal and replacement of a roof membrane where there is existing roof insulation integral to or below the roof deck
  7. Removal and replacement of a roof membrane where the insulation is installed entirely above the roof deck, a minimum of R-20 insulation shall be permitted where the placement of additional insulation greater than R-20 insulation would require either of the following:
    1. Raising the height of parapets, weep systems, or through wall flashings where roof abuts adjoining walls or parapets.
    2. Raising the height of mechanical or electrical equipment, mechanical curbs, roof hatches, skylight curbs, service equipment, piping, conduit, duct work, roof platforms, ladders, stairs, guard rails, expansion joints, roof davits, or door thresholds.
  8. Replacement of existing fenestration, provided that the area of the replacement fenestration does not exceed 25% of the total fenestration area of an existing building and that the U-factor and SHGC, will be equal to or lower than before the fenestration replacement.
Determine the climate zone for the location. For U.S. locations, follow the procedure in Section 5.1.4.1. For international locations, follow the procedure in Section 5.1.4.2.
Use Figure B1-1 or Table B1-1 in Appendix B to determine the required climate zone.

Exception: If there are recorded historical climatic data available for a construction site, they may be used to determine compliance if approved by the building official.

For locations in Canada that are listed in Table B1-2 in Appendix B, use this table to determine the required climate zone number and, when a climate zone letter is also required, use Table B1-4 and the Major Climate Type Definitions in Appendix B to determine the letter (A, B, or C). For locations in other international countries that are listed in Table B1-3, use this table to determine the required climate zone number and, when a climate zone letter is also required, use Table B1-4 and the Major Climate Type Definitions in Appendix B to determine the letter (A, B, or C). For all international locations that are not listed either in Table B1-2 or B1-3, use Table B1-4 and the Major Climate Type Definitions in Appendix B to determine both the climate zone letter and number.
For the appropriate climate, space-conditioning category, and class of construction, the building envelope shall comply with Section 5.1, "General"; Section 5.4, "Mandatory Provisions"; Section 5.7, "Submittals"; Section 5.8, "Product Information and Installation Requirements"; and either
  1. Section 5.5, "Prescriptive Building Envelope Option," provided that the fenestration area does not exceed the maximum allowed by Section 5.5.4.2, or
  2. Section 5.6, "Building Envelope Trade-Off Option."
Projects using the Energy Cost Budget Method (see Section 11 of this standard) must comply with Section 5.4, the mandatory provisions of this section, as a portion of that compliance path.
Where insulation is required in Section 5.5 or 5.6, it shall comply with the requirements found in Sections 5.8.1.1 through 5.8.1.10.
Procedures for determining fenestration and door performance are described in Section 5.8.2. Product samples used for determining fenestration performance shall be production line units or representative of units purchased by the consumer or contractor.
The entire building envelope shall be designed and constructed with a continuous air barrier.

Exceptions:

  1. Semiheated spaces in Climate Zones 1 through 6.
  2. Single wythe concrete masonry buildings in Climate Zone 2B.
The air barrier shall be designed and noted in the following manner:
  1. All air barrier components of each building envelope assembly shall be clearly identified or otherwise noted on construction documents.
  2. The joints, interconnections, and penetrations of the air barrier components, including lighting fixtures, shall be detailed or otherwise noted.
  3. The continuous air barrier shall extend over all surfaces of the building envelope (at the lowest floor, exterior walls, and ceiling or roof).
  4. The continuous air barrier shall be designed to resist positive and negative pressures from wind, stack effect, and mechanical ventilation.
The following areas of the continuous air barrier in the building envelope shall be wrapped, sealed, caulked, gasketed, or taped in an approved manner to minimize air leakage:
  1. Joints around fenestration and door frames (both manufactured and site-built)
  2. Junctions between walls and floors, between walls at building corners, and between walls and roofs or ceilings
  3. Penetrations through the air barrier in building envelope roofs, walls, and floors
  4. Building assemblies used as ducts or plenums
  5. Joints, seams, connections between planes, and other changes in air barrier materials
Continuous air barrier materials and assemblies for the opaque building envelope shall comply with one of the following requirements:
  1. Materials that have an air permeance not exceeding 0.004 cfm/ft2 under a pressure differential of 0.3 in. H2O (1.57 psf) when tested in accordance with ASTM E 2178. The following materials meet these requirements:
    1. Plywood—minimum 3/8 in.
    2. Oriented strand board—minimum 3/8 in.
    3. Extruded polystyrene insulation board—minimum 1/ 2 in.
    4. Foil-faced urethane insulation board—minimum 1/2 in.
    5. Exterior gypsum sheathing or interior gypsum board—minimum 1/2 in.
    6. Cement board—minimum 1/2 in.
    7. Built-up roofing membrane
    8. Modified bituminous roof membrane
    9. Fully adhered single-ply roof membrane
    10. A Portland cement/sand parge, stucco, or gypsum plaster—minimum 1/2 in. thick
    11. Cast-in-place and precast concrete
    12. Sheet metal
    13. Closed-cell 2 lb/ft3 nominal density spray polyurethane foam—minimum 1 in.
  2. Assemblies of materials and components (sealants, tapes, etc.) that have an average air leakage not to exceed 0.04 cfm/ft2 under a pressure differential of 0.3 in. H2O (1.57 psf) when tested in accordance with ASTM E 2357, ASTM E 1677, ASTM E 1680, or ASTM E283. The following assemblies meet these requirements:
    1. Concrete masonry walls that are
      1. fully grouted, or
      2. painted to fill the pores.
Air leakage for fenestration and doors shall be determined in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, NFRC 400, or ASTM E283 as specified below. Air leakage shall be determined by a laboratory accredited by a nationally recognized accreditation organization, such as the National Fenestration Rating Council, and shall be labeled and certified by the manufacturer. Air leakage shall not exceed
  1. 1.0 cfm/ft2 for glazed swinging entrance doors and revolving doors, tested at a pressure of at least 1.57 psf in accordance with AAMA/WDMA/CSA 101/I.S.2/ A440, NFRC 400, or ASTM E283;
  2. 0.06 cfm/ft2 for curtainwall and storefront glazing, tested at a pressure of at least 1.57 psf or higher in accordance with NFRC 400 or ASTM E283;
  3. 0.3 cfm/ft2 for unit skylights having condensation weep-age openings, tested at a pressure of at least 1.57 psf in accordance with AAMA/WDMA/CSA 101/I.S.2/A440 or NFRC 400, or 0.5 cfm/ft2 tested at a pressure of at least 6.24 psf in accordance with AAMA/WDMA/CSA 101/ I.S.2/A440;
  4. 1.3 cfm/ft2 for nonswinging doors intended for vehicular access and material transportation, with a minimum opening rate of 32 in./s, tested at a pressure of at least 1.57 psf or higher in accordance with ANSI/DASMA 105, NFRC 400, or ASTM E283.
  5. 0.4 cfm/ft2 for other nonswinging opaque doors, glazed sectional garage doors, and upward acting nonswinging glazed doors tested at a pressure of at least 1.57 psf or higher in accordance with ANSI/DASMA 105, NFRC 400, or ASTM E283; and
  6. 0.2 cfm/ft2 for all other products tested at a pressure of at least 1.57 psf in accordance with AAMA/WDMA/CSA 101/I.S.2/A440 or NFRC 400, or 0.3 cfm/ft2 tested at a pressure of at least 6.24 psf in accordance with AAMA/ WDMA/CSA 101/I.S/A440.

Exceptions:

  1. Field-fabricated fenestration and doors
  2. Metal coiling doors in semiheated spaces in Climate Zones 1 through 6
  3. Products in buildings that comply with a whole building air leakage rate of 0.4 cfm/ft2 under a pressure differential of 0.3 in. H2O, 1.57 psf when tested in accordance with ASTM E 779
In Climate Zones 4 through 8, cargo doors and loading dock doors shall be equipped with weatherseals to restrict infiltration when vehicles are parked in the doorway.

5.4.3.4 Vestibules

AMENDMENT
This section has been amended at the state or city level.
Building entrances that separate conditioned space from the exterior shall be protected with an enclosed vestibule, with all doors opening into and out of the vestibule equipped with self-closing devices. Vestibules shall be designed so that in passing through the vestibule it is not necessary for the interior and exterior doors to open at the same time. Interior and exterior doors shall have a minimum distance between them of not less than 7 feet when in the closed position. The floor area of each vestibule shall not exceed the greater of 50 feet2 or 2% of the gross conditioned floor area for that level of the building. The exterior envelope of conditioned vestibules shall comply with the requirements for a conditioned space. The interior and exterior envelope of unconditioned vestibules shall comply with the requirements for a semiheated space.

Exceptions:

  1. Doors not intended to be used by the public, such as doors to storage, mechanical, electrical, or equipment rooms.
  2. Doors opening directly from a sleeping unit or dwelling unit.
  3. Doors that open directly from a space less than 3,000 feet2 (298 m2) in area.
  4. Revolving doors.
  5. Doors used primarily to facilitate shipping, receiving, or material handling.
  6. Doors with no exterior entrance hardware.
  7. Doors leading solely to outdoor eating areas.
  8. Overhead doors.
Where vestibules are required under Section 5.4.3.4, for spaces having a gross conditioned floor area for that level of the building of 40,000 ft2 and greater, and when the doors opening into and out of the vestibule are equipped with automatic, electrically driven, self-closing devices, the interior and exterior doors shall have a minimum distance between them of not less than 16 ft.

Table 5.5-1 Building Envelope Requirements for Climate Zone 1 (A,B,C)*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.048 R-20 c.i.   U-0.039 R-25 c.i.   U-0.218 R-3.8 c.i.  
Metal Buildinga U-0.041 R-10 + R-19 FC   U-0.041 R-10 + R-19 FC   U-0.115 R-10  
Attic and Other U-0.027 R-38   U-0.027 R-38   U-0.081 R-13  
Walls, above Grade
Mass U-0.580 NR   U-0.151b R-5.7 c.i.b   U-0.580 NR  
Metal Building U-0.094 R-0 + R-9.8 c.i.   U-0.094 R-0 + R-9.8 c.i.   U-0.352 NR  
Steel Framed U-0.124 R-13   U-0.124 R-13   U-0.352 NR  
Wood Framed and Other U-0.089 R-13   U-0.089 R-13   U-0.292 NR  
Wall, below Grade
Below Grade Wall C-1.140 NR   C-1.140 NR   C-1.140 NR  
Floors
Mass U-0.322 NR   U-0.322 NR   U-0.322 NR  
Steel Joist U-0.350 NR   U-0.350 NR   U-0.350 NR  
Wood Framed and Other U-0.282 NR   U-0.282 NR   U-0.282 NR  
Slab-on-Grade Floors
Unheated F-0.730 NR   F-0.730 NR   F-0.730 NR  
Heated F-1.020 R-7.5 for 12 in.   F-1.020 R-7.5 for 12 in.   F-1.020 R-7.5 for 12 in.  
Opaque Doors
Swinging U-0.700     U-0.500     U-0.700    
Nonswinging U-1.450     U-0.500     U-1.450    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.50c     U-0.50c     U-0.93    
Metal framing, fixed U-0.57c     U-0.57c     U-1.20    
Metal framing, operable U-0.65c SHGC-0.25 1.10 U-0.65c SHGC-0.25 1.10 U-1.20 NR NR
Metal framing, entrance door U-1.10c     U-1.10c     U-1.10c    
Skylight, 0%—3% of Roof
All types U-0.75 SHGC-0.35 NR U-0.75 SHGC-0.35 NR U-1.80 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

b. Exception to Section 5.5.3.2 applies for mass walls above grade.

c. For locations in Climate Zone 1 with a cooling design temperature of 95°F and greater, see Section 5.5.4.3 for the maximum U-factors for vertical fenestration.

Table 5.5-2 Building Envelope Requirements for Climate Zone 2 (A,B)*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.039 R-25 c.i.   U-0.039 R-25 c.i.   U-0.173 R-5 c.i.  
Metal Buildinga U-0.041 R-10 + R-19 FC   U-0.041 R-10 + R-19 FC   U-0.096 R-16  
Attic and Other U-0.027 R-38   U-0.027 R-38   U-0.053 R-19  
Walls, above Grade
Mass U-0.151b R-5.7 c.i.b   U-0.123 R-7.6 c.i.   U-0.580 NR  
Metal Building U-0.094 R-0 + R-9.8 c.i.   U-0.094 R-0 + R-9.8 c.i.   U-0.162 R-13  
Steel Framed U-0.084 R-13 + R-3.8 c.i.   U-0.064 R-13 + R-7.5 c.i.   U-0.124 R-13  
Wood Framed and Other U-0.089 R-13   U-0.089 R-13   U-0.089 R-13  
Wall, below Grade
Below Grade Wall C-1.140 NR   C-1.140 NR   C-1.140 NR  
Floors
Mass U-0.107 R-6.3 c.i.   U-0.087 R-8.3 c.i.   U-0.322 NR  
Steel Joist U-0.038 R-30   U-0.038 R-30   U-0.069 R-13  
Wood Framed and Other U-0.033 R-30   U-0.033 R-30   U-0.066 R-13  
Slab-on-Grade Floors
Unheated F-0.730 NR   F-0.730 NR   F-0.730 NR  
Heated F-0.900 R-10 for 24 in.   F-0.860 R-15 for 24 in.   F-1.020 R-7.5 for 12 in.  
Opaque Doors
Swinging U-0.700     U-0.500     U-0.700    
Nonswinging U-0.500     U-0.500     U-1.450    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.40     U-0.40     U-0.93    
Metal framing, fixed U-0.57     U-0.57     U-1.20    
Metal framing, operable U-0.65 SHGC-0.25 1.10 U-0.65 SHGC-0.25 1.10 U-1.20 NR NR
Metal framing, entrance door U-0.83     U-0.77     U-0.83    
Skylight, 0%—3% of Roof
All types U-0.65 SHGC-0.35 NR U-0.65 SHGC-0.35 NR U-1.80 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

b. Exception to Section 5.5.3.2 applies for mass walls above grade.

Table 5.5-3 Building Envelope Requirements for Climate Zone 3 (A,B,C)*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.039 R-25 c.i.   U-0.039 R-25 c.i.   U-0.119 R-7.6 c.i.  
Metal Buildinga U-0.041 R-10 + R-19 FC   U-0.041 R-10 + R-19 FC   U-0.096 R-16  
Attic and Other U-0.027 R-38   U-0.027 R-38   U-0.053 R-19  
Walls, above Grade
Mass U-0.123 R-7.6 c.i.   U-0.104 R-9.5 c.i.   U-0.580 NR  
Metal Building U-0.094 R-0 + R-9.8 c.i.   U-0.072 R-0 + R-13 c.i.   U-0.162 R-13  
Steel Framed U-0.077 R-13 + R-5 c.i.   U-0.064 R-13 + R-7.5 c.i.   U-0.124 R-13  
Wood Framed and Other U-0.089 R-13   U-0.064 R-13 + R-3.8 c.i. or R-20   U-0.089 R-13  
Wall, below Grade
Below Grade Wall C-1.140 NR   C-1.140 NR   C-1.140 NR  
Floors
Mass U-0.074 R-10 c.i.   U-0.074 R-10 c.i.   U-0.137 R-4.2 c.i.  
Steel Joist U-0.038 R-30   U-0.038 R-30   U-0.052 R-19  
Wood Framed and Other U-0.033 R-30   U-0.033 R-30   U-0.051 R-19  
Slab-on-Grade Floors
Unheated F-0.730 NR   F-0.540 R-10 for 24 in.   F-0.730 NR  
Heated F-0.860 R-15 for 24 in.   F-0.860 R-15 for 24 in.   F-1.020 R-7.5 for 12 in.  
Opaque Doors
Swinging U-0.700     U-0.500     U-0.700    
Nonswinging U-0.500     U-0.500     U-1.450    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.35     U-0.35     U-0.87    
Metal framing, fixed U-0.50     U-0.50     U-1.20    
Metal framing, operable U-0.60 SHGC-0.25 1.10 U-0.60 SHGC-0.25 1.10 U-1.20 NR NR
Metal framing, entrance door U-0.77     U-0.68     U-0.77    
Skylight, 0%—3% of Roof
All types U-0.55 SHGC-0.35 NR U-0.55 SHGC-0.35 NR U-1.70 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

Table 5.5-4 Building Envelope Requirements for Climate Zone 4 (A,B,C)*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.032 R-30 c.i.   U-0.032 R-30 c.i.   U-0.093 R-10 c.i.  
Metal Buildinga U-0.037 R-19 + R-11 Ls or
R-25 + R-8 Ls
  U-0.037 R-19 + R-11 Ls or
R-25 + R-8 Ls
  U-0.082 R-19  
Attic and Other U-0.021 R-49   U-0.021 R-49   U-0.034 R-30  
Walls, above Grade
Mass U-0.104 R-9.5 c.i.   U-0.090 R-11.4 c.i.   U-0.580 NR  
Metal Building U-0.060 R-0 + R-15.8 c.i.   U-0.050 R-0 + R-19 c.i.   U-0.162 R-13  
Steel Framed U-0.064 R-13 + R-7.5 c.i.   U-0.064 R-13 + R-7.5 c.i.   U-0.124 R-13  
Wood Framed and Other U-0.064 R-13 + R-3.8 c.i.
or R-20
  U-0.064 R-13 + R-3.8 c.i. or R-20   U-0.089 R-13  
Wall, below Grade
Below Grade Wall C-0.119 R-7.5 c.i.   C-0.092 R-10 c.i.   C-1.140 NR  
Floors
Mass U-0.057 R-14.6 c.i.   U-0.051 R-16.7 c.i.   U-0.107 R-6.3 c.i.  
Steel Joist U-0.038 R-30   U-0.038 R-30   U-0.052 R-19  
Wood Framed and Other U-0.033 R-30   U-0.033 R-30   U-0.051 R-19  
Slab-on-Grade Floors
Unheated F-0.520 R-15 for 24 in.   F-0.520 R-15 for 24 in.   F-0.730 NR  
Heated F-0.843 R-20 for 24 in.   F-0.688 R-20 for 48 in.   F-0.900 R-10 for 24 in.  
Opaque Doors
Swinging U-0.500     U-0.500     U-0.700    
Nonswinging U-0.500     U-0.500     U-1.450    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.35     U-0.35     U-0.51    
Metal framing, fixed U-0.42     U-0.42     U-0.73    
Metal framing, operable U-0.50 SHGC-0.40 1.10 U-0.50 SHGC-0.40 1.10 U-0.81 NR NR
Metal framing, entrance door U-0.77     U-0.68     U-0.77    
Skylight, 0%—3% of Roof
All types U-0.50 SHGC-0.40 NR U-0.50 SHGC-0.40 NR U-1.15 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

Table 5.5-5 Building Envelope Requirements for Climate Zone 5 (A,B,C)*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.032 R-30 c.i.   U-0.032 R-30 c.i.   U-0.063 R-15 c.i.  
Metal Buildinga U-0.037 R-19 + R-11 Ls or
R-25 + R-8 Ls
  U-0.037 R-19 + R-11 Ls or
R-25 + R-8 Ls
  U-0.082 R-19  
Attic and Other U-0.021 R-49   U-0.021 R-49   U-0.034 R-30  
Walls, above Grade
Mass U-0.090 R-11.4 c.i.   U-0.080 R-13.3 c.i.   U-0.151b R-5.7 c.i.b  
Metal Building U-0.050 R-0 + R-19 c.i.   U-0.050 R-0 + R-19 c.i.   U-0.094 R-0 + R-9.8 c.i.  
Steel Framed U-0.055 R-13 + R-10 c.i.   U-0.055 R-13 + R-10 c.i.   U-0.084 R-13+R-3.8 c.i.  
Wood Framed and Other U-0.051 R-13 + R-7.5 c.i. or
R-19 + R-5 c.i.
  U-0.051 R-13 + R-7.5 c.i. or
R-19 + R-5 c.i.
  U-0.089 R-13  
Wall, below Grade
Below Grade Wall C-0.119 R-7.5 c.i.   C-0.092 R-10 c.i.   C-1.140 NR  
Floors
Mass U-0.057 R-14.6 c.i.   U-0.051 R-16.7 c.i.   U-0.107 R-6.3 c.i.  
Steel Joist U-0.038 R-30   U-0.038 R-30   U-0.052 R-19  
Wood Framed and Other U-0.033 R-30   U-0.033 R-30   U-0.051 R-19  
Slab-on-Grade Floors
Unheated F-0.520 R-15 for 24 in.   F-0.510 R-20 for 24 in.   F-0.730 NR  
Heated F-0.688 R-20 for 48 in.   F-0.688 R-20 for 48 in.   F-0.900 R-10 for 24 in.  
Opaque Doors
Swinging U-0.500     U-0.500     U-0.700    
Nonswinging U-0.500     U-0.500     U-1.450    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.32     U-0.32     U-0.45    
Metal framing, fixed U-0.42     U-0.42     U-0.62    
Metal framing, operable U-0.50 SHGC-0.40 1.10 U-0.50 SHGC-0.40 1.10 U-0.70 NR NR
Metal framing, entrance door U-0.77     U-0.68     U-0.77    
Skylight, 0%—3% of Roof
All types U-0.50 SHGC-0.40 NR U-0.50 SHGC-0.40 NR U-0.98 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

b. Exception to Section 5.5.3.2 applies for mass walls above grade.

Table 5.5-6 Building Envelope Requirements for Climate Zone 6 (A,B)*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.032 R-30 c.i.   U-0.032 R-30 c.i.   U-0.063 R-15 c.i.  
Metal Buildinga U-0.031 R-25 + R-11 Ls   U-0.029 R-30 + R-11 Ls   U-0.060 R-19 + R-19  
Attic and Other U-0.021 R-49   U-0.021 R-49   U-0.034 R-30  
Walls, above Grade
Mass U-0.080 R-13.3 c.i.   U-0.071 R-15.2 c.i.   U-0.151b R-5.7 c.i.b  
Metal Building U-0.050 R-0 + R-19 c.i.   U-0.050 R-0 + R-19 c.i.   U-0.094 R-0 + R-9.8 c.i.  
Steel Framed U-0.049 R-13 + R-12.5 c.i.   U-0.049 R-13 + R-12.5 c.i.   U-0.084 R-13+R-3.8 c.i.  
Wood Framed and Other U-0.051 R-13 + R-7.5 c.i. or
R-19 + R-5 c.i.
  U-0.051 R-13 + R-7.5 c.i. or
R-19 + R-5 c.i.
  U-0.089 R-13  
Wall, below Grade
Below Grade Wall C-0.092 R-10 c.i.   C-0.063 R-15 c.i.   C-0.119 R-7.5 c.i  
Floors
Mass U-0.051 R-16.7 c.i.   U-0.051 R-16.7 c.i.   U-0.087 R-8.3 c.i.  
Steel Joist U-0.032 R-38   U-0.032 R-38   U-0.052 R-19  
Wood Framed and Other U-0.027 R-38   U-0.027 R-38   U-0.051 R-19  
Slab-on-Grade Floors
Unheated F-0.510 R-20 for 24 in.   F-0.434 R-20 for 48 in.   F-0.730 NR  
Heated F-0.688 R-20 for 48 in.   F-0.671 R-25 for 48 in.   F-0.860 R-15 for 24 in.  
Opaque Doors
Swinging U-0.500     U-0.500     U-0.700    
Nonswinging U-0.500     U-0.500     U-0.500    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.32     U-0.32     U-0.45    
Metal framing, fixed U-0.42     U-0.42     U-0.51    
Metal framing, operable U-0.50 SHGC-0.40 1.10 U-0.50 SHGC-0.40 1.10 U-0.59 NR NR
Metal framing, entrance door U-0.77     U-0.68     U-0.77    
Skylight, 0%—3% of Roof
All types U-0.50 SHGC-0.40 NR U-0.50 SHGC-0.40 NR U-0.85 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

b, Exception to Section 5.5.3.2 applies for mass walls above grade.

Table 5.5-7 Building Envelope Requirements for Climate Zone 7*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.028 R-35 c.i.   U-0.028 R-35 c.i.   U-0.039 R-25 c.i.  
Metal Buildinga U-0.029 R-30 + R-11 Ls   U-0.029 R-30 + R-11 Ls   U-0.037 R-19 + R-11 Ls or
R-25 + R-8 Ls
 
Attic and Other U-0.017 R-60   U-0.017 R-60   U-0.027 R-38  
Walls, above Grade
Mass U-0.071 R-15.2 c.i.   U-0.071 R-15.2 c.i.   U-0.123 R-7.6 c.i.  
Metal Building U-0.044 R-0 + R.22.1 c.i.   U-.044 R-0 + R.22.1 c.i.   U-0.072 R-0 + R-13 c.i.  
Steel Framed U-0.049 R-13 + R-12.5 c.i.   U-0.042 R-13 + R-15.6 c.i.   U-0.064 R-13 + R-7.5 c.i.  
Wood Framed and Other U-0.051 R-13 + R-7.5 c.i. or
R-19 + R-5 c.i.
  U-0.051 R-13 + R-7.5 c.i. or
R-19 + R-5 c.i.
  U-0.064 R-13 + R-3.8 c.i.  
Wall, below Grade
Below Grade Wall C-0.063 R-15 c.i.   C-0.063 R-15 c.i.   C-0.119 R-7.5 c.i  
Floors
Mass U-0.042 R-20.9 c.i.   U-0.042 R-20.9 c.i.   U-0.074 R-10.4 c.i.  
Steel Joist U-0.032 R-38   U-0.032 R-38   U-0.052 R-19  
Wood Framed and Other U-0.027 R-38   U-0.027 R-38   U-0.051 R-19  
Slab-on-Grade Floors
Unheated F-0.510 R-20 for 24 in.   F-0.434 R-20 for 48 in.   F-0.730 NR  
Heated F-0.671 R-25 for 48 in.   F-0.671 R-25 for 48 in.   F-0.860 R-15 for 24 in.  
Opaque Doors
Swinging U-0.500     U-0.500     U-0.700    
Nonswinging U-0.500     U-0.500     U-0.500    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.32     U-0.32     U-0.32    
Metal framing, fixed U-0.38     U-0.38     U-0.38    
Metal framing, operable U-0.40 SHGC-0.45 1.10 U-0.40 SHGC-0.45 1.10 U-0.44 NR NR
Metal framing, entrance door U-0.77     U-0.68     U-0.77    
Skylight, 0%—3% of Roof
All types U-0.50 NR NR U-0.50 NR NR U-0.85 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

Table 5.5-8 Building Envelope Requirements for Climate Zone 8*

Opaque Elements Nonresidential   Residential   Semiheated  
Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value   Assembly Maximum Insulation Min. R-Value  
Roofs
Insulation Entirely above Deck U-0.028 R-35 c.i.   U-0.028 R-35 c.i.   U-0.039 R-25 c.i.  
Metal Buildinga U-0.026 R-25 + R-11+R-11 Ls   U-0.026 R-25 + R-11+R-11 Ls   U-0.037 R-19 + R-11 Ls or
R-25 + R-8 Ls
 
Attic and Other U-0.017 R-60   U-0.017 R-60   U-0.027 R-38  
Walls, above Grade
Mass U-0.048 R-19 c.i.   U-0.048 R-19 c.i.   U-0.104 R-9.5 c.i.  
Metal Building U-0.039 R-0 + R.25 c.i.   U-0.039 R-0 + R.25 c.i.   U-0.060 R-0 + R-15.8 c.i.  
Steel Framed U-0.037 R-13 + R-18.8 c.i.   U-0.037 R-13 + R-18.8 c.i.   U-0.064 R-13 + R-7.5 c.i.  
Wood Framed and Other U-0.032 R-13 + R-18.8 c.i.   U-0.032 R-13 + R-18.8 c.i.   U-0.051 R-13 + R-7.5 c.i.  
Wall, below Grade
Below Grade Wall C-0.063 R-15 c.i.   C-0.063 R-15 c.i.   C-0.119 R-7.5 c.i  
Floors
Mass U-0.038 R-23 c.i.   U-0.038 R-23 c.i.   U-0.064 R-12.5 c.i.  
Steel Joist U-0.032 R-38   U-0.032 R-38   U-0.052 R-19  
Wood Framed and Other U-0.027 R-38   U-0.027 R-38   U-0.033 R-30  
Slab-on-Grade Floors
Unheated F-0.434 R-20 for 48 in.   F-0.424 R-25 for 48 in.   F-0.540 R-10 for 24 in.  
Heated F-0.671 R-25 for 48 in.   F-0.373 R-20 full slab   F-0.860 R-15 for 24 in.  
Opaque Doors
Swinging U-0.500     U-0.500     U-0.500    
Nonswinging U-0.500     U-0.500     U-0.500    
Fenestration Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC Assembly Max. U Assembly Max. SHGC Assembly Min. VT/SHGC
Vertical Fenestration, 0%—40% of Wall   (for all frame types)   (for all frame types)   (for all frame types)
Nonmetal framing, all U-0.32     U-0.32     U-0.32    
Metal framing, fixed U-0.38     U-0.38     U-0.38    
Metal framing, operable U-0.40 SHGC-0.45 1.10 U-0.40 SHGC-0.45 1.10 U-0.44 NR NR
Metal framing, entrance door U-0.77     U-0.68     U-0.77    
Skylight, 0%—3% of Roof
All types U-0.50 NR NR U-0.50 NR NR U-0.85 NR NR

* The following definitions apply: 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.

a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2).

For a conditioned space, the exterior building envelope shall comply with either the nonresidential or residential requirements in Tables 5.5-1 through 5.5-8 for the appropriate climate.
If a building contains any semiheated space or unconditioned space, then the semi-exterior building envelope shall comply with the requirements for semiheated space in Tables 5.5-1 through 5.5-8 for the appropriate climate. (See Figure 5.5.2.)

Figure 5.5.2. Exterior and semiexterior building envelope.

For all opaque surfaces except doors, compliance shall be demonstrated by one of the following two methods:
  1. Minimum rated R-values of insulation for the thermal resistance of the added insulation in framing cavities and continuous insulation only. Specifications listed in Normative Appendix A for each class of construction shall be used to determine compliance.
  2. Maximum U-factor, C-factor, or F-factor for the entire assembly. The values for typical construction assemblies listed in Normative Appendix A shall be used to determine compliance.

Exceptions:

  1. For assemblies significantly different than those in Appendix A, calculations shall be performed in accordance with the procedures required in Appendix A.
  2. For multiple assemblies within a single class of construction for a single space-conditioning category, compliance shall be shown for either (a) the most restrictive requirement or (b) an area-weighted average U-factor, C-factor, or F-factor.
All roofs shall comply with the insulation values specified in Tables 5.5-1 through 5.5-8. Skylight curbs shall be insulated to the level of roofs with insulation entirely above deck or R-5.0, whichever is less.
Roofs in Climate Zones 1 through 3 shall have one of the following:
  1. 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-1 Standard
  2. 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 2.1 Btu/h•ft2•°F, based on three-year-aged solar reflectance and three-year-aged thermal emittance tested in accordance with CRRC-1 Standard
  3. Increased roof insulation levels found in Table 5.5.3.1.1
    Exceptions:
    1. Ballasted roofs with a minimum stone ballast of 17 lb/ft2 or 23 lb/ft2 pavers
    2. Vegetated roof systems that contain a minimum thickness of 2.5 in. of growing medium and covering a minimum of 75% of the roof area with durable plantings
    3. Roofs where a minimum of 75% of the roof area
      1. is shaded during the peak sun angle on June 21 by permanent components or features of the building;
      2. is covered by offset photovoltaic arrays, building-integrated photovoltaic arrays, or solar air or water collectors; or
      3. is permitted to be interpolated using a combination of 1 and 2 above
    4. Steep-sloped roofs
    5. Low-sloped metal building roofs in Climate Zones 2 and 3
    6. Roofs over ventilated attics, roofs over semiheated spaces, or roofs over conditioned spaces that are not cooled spaces
    7. Asphaltic membranes in Climate Zones 2 and 3

The values for three-year-aged solar reflectance and three-year-aged thermal emittance shall be determined by a laboratory accredited by a nationally recognized accreditation organization and shall be labeled and certified by the manufacturer.

Table 5.5.3.1.1 Increased Roof Insulation Levels

Roofs Nonresidential Residential
Opaque Elements Assembly Maximum Insulation Min. R-Value Assembly Maximum Insulation Min. R-Value
Insulation entirely above deck U-0.030 R-33 U-0.029 R-34
Metal buildings U-0.028 R-35    
All above-grade walls shall comply with the insulation values specified in Tables 5.5-1 through 5.5-8.

Exception: Alternatively, for mass walls, where the requirement in Tables 5.5-1 through 5.5-8 is for a maximum assembly U-0.151 followed by footnote "b," ASTM C90 concrete block walls, ungrouted or partially grouted at 32 in. or less on center vertically and 48 in.or less on center horizontally, shall have ungrouted cores filled with material having a maximum thermal conductivity of 0.44 Btu•in./h•ft2•°F. Other mass walls with integral insulation shall meet the criteria when their U-factors are equal to or less than those for the appropriate thickness and density in the "Partly Grouted, Cells Insulated" column of Table A3.1-3.

When a wall consists of both above-grade and below-grade portions, the entire wall for that story shall be insulated on either the exterior or the interior or be integral.

  1. If insulated on the interior, the wall shall be insulated to the above-grade wall requirements.
  2. If insulated on the exterior or integral, the below-grade wall portion shall be insulated to the below-grade wall requirements, and the above-grade wall portion shall be insulated to the above-grade wall requirements.
Below-grade walls shall have a rated R-value of insulation no less than the insulation values specified in Tables 5.5-1 through 5.5-8.

Exception: Where framing, including metal and wood studs, is used, compliance shall be based on the maximum assembly C-factor.

All floors shall comply with the insulation values specified in Tables 5.5-1 through 5.5-8.
All slab-on-grade floors, including heated slab-on-grade floors and unheated slab-on-grade floors, shall comply with the insulation values specified in Tables 5.5-1 through 5.5-8.
All opaque doors shall have a U-factor not greater than that specified in Tables 5.5-1 through 5.5-8.
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: If there are multiple assemblies within a single class of construction for a single space-conditioning category, compliance shall be based on an area-weighted average U-factor, SHGC, VT/SHGC, or LSG. It is not acceptable to do an area-weighted average across multiple classes of construction or multiple space-conditioning categories.

The total vertical fenestration area shall not be greater than that specified in Tables 5.5-1 through 5.5-8.

Exception: Vertical fenestration complying with Exception (3) to Section 5.5.4.4.1.

The total skylight area shall not be greater than that specified in Tables 5.5-1 through 5.5-8.

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) to Section 5.5.4.4.2 and the total daylight area under skylights is a minimum of half the floor area of the space.

In any enclosed space in a building that is
  1. 2500 ft2 and greater;
  2. directly under a roof with ceiling heights greater than 15 ft; and
  3. one of the following space types: office, lobby, atrium, concourse, corridor, storage (including nonrefrigerated warehouse), gymnasium, fitness/exercise area, playing area, gymnasium seating area, convention exhibit/event space, courtroom, automotive service, fire station engine room, manufacturing corridor/transition and bay areas, retail, library reading and stack areas, distribution/sorting area, transportation baggage and seating areas, or workshop,

    the total daylight area under skylights shall be a minimum of half the floor area and either

  1. provide a minimum skylight area to daylight area under skylights of 3% with a skylight VT of at least 0.40 or
  2. provide a minimum skylight effective aperture of at least 1%.

These skylights shall have a glazing material or diffuser with a measured haze value greater than 90% when tested according to ASTM D1003. General lighting in the daylight area shall be controlled as described in Section 9.4.1.1(f).

Exceptions:

  1. Enclosed spaces in Climate Zones 6 through 8
  2. Enclosed spaces where it is documented that existing structures or natural objects block direct beam sunlight on at least half of the roof over the enclosed space for more than 1500 daytime hours per year between 8 a.m. and 4 p.m.
  3. Enclosed spaces where the daylight area under roof monitors is greater than 50% of the enclosed space floor area
  4. Enclosed spaces where it is documented that 90% of the skylight area is shaded on June 21 in the Northern Hemisphere (December 21 in the Southern Hemisphere) at noon by permanent architectural features of the building
  5. Enclosed spaces where the total area minus the primary and secondary sidelighted area(s) is less than 2500 ft2 and where the lighting is controlled according to sidelighting requirements described in Section 9.4.1.1(e)
Fenestration shall have a U-factor not greater than that specified in Tables 5.5-1 through 5.5-8.

However, for locations in Climate Zone 1 with a cooling design temperature of 95°F and greater, the maximum allowed U-factors for vertical fenestration for all conditioned spaces, nonresidential and residential, are U-0.32 for nonmetal framing, U-0.50 for fixed metal framing, U-0.65 for operable metal framing, and U-0.83 for entrance door metal framing.

Exception: The U-factor for skylights is permitted to be increased to no greater than 0.90 Btu/h•ft2•°F in Climate Zones 1 through 3 and 0.75 Btu/h•ft2•°F in Climate Zones 4 through 8, provided the skylights meet all of the criteria in Exception (1) to Section 5.5.4.4.2.

Vertical fenestration shall have an SHGC not greater than that specified in Tables 5.5-1 through 5.5-8.

Exceptions:

  1. For demonstrating compliance for vertical fenestration shaded by opaque permanent projections that will last as long as the building itself, the SHGC in the proposed building shall be reduced by using the multipliers in Table 5.5.4.4.1. Permanent projections consisting of open louvers shall be considered to provide shading, provided that no sun penetrates the louvers during the peak sun angle on June 21.

    Table 5.5.4.4.1 SHGC Multipliers for Permanent Projections

    Projection Factor SHGC Multiplier (all Other Orientations) SHGC Multiplier (North-Oriented)
    0—0.10 1.00 1.00
    >0.10—0.20 0.91 0.95
    >0.20—0.30 0.82 0.91
    >0.30—0.40 0.74 0.87
    >0.40—0.50 0.67 0.84
    >0.50—0.60 0.61 0.81
    >0.60—0.70 0.56 0.78
    >0.70—0.80 0.51 0.76
    >0.80—0.90 0.47 0.75
    >0.90—1.00 0.44 0.73
  2. For demonstrating compliance for vertical fenestration shaded by partially opaque permanent projections (e.g., framing with glass or perforated metal) that will last as long as the building itself, the projection factor (PF) shall be reduced by multiplying it by a factor of Os, which is derived as follows:

    Os = (Ai × Oi) + (Af × Of)

    where

    Os = percent opacity of the shading device
    Ai = percent of the area of the shading device that is a partially opaque infill
    Oi = percent opacity of the infill for glass Oi = (100% — Ts), where Ts is the solar transmittance as determined in accordance with NFRC 300; for perforated or decorative metal panels, Oi = percentage of solid material
    Af = percent of the area of the shading device that represents the framing members
    Of = percent opacity of the framing members; if solid, then 100%

    The SHGC in the proposed building then shall be reduced by using the multipliers in Table 5.5.4.4.1 for each fenestration product.

  3. Vertical fenestration that is located on the street side of the street-level story only, provided that
    1. the street side of the street-level story does not exceed 20 ft in height,
    2. the fenestration has a continuous overhang with a weighted average PF greater than 0.5, and
    3. 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.

    When this exception is utilized, 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.

  4. For dynamic glazing, the minimum SHGC shall be used to demonstrate compliance with this section. Dynamic glazing shall be considered separately from other vertical fenestration, and area-weighted averaging with other vertical fenestration that is not dynamic glazing shall not be permitted.
  5. Vertical fenestration that is north-oriented shall be allowed to have a maximum solar heat gain coefficient SHGC-0.05 greater than that specified in Tables 5.5-1 through 5.5-8. When this exception is utilized, 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.
Skylights shall have an SHGC not greater than that specified in Tables 5.5-1 through 5.5-8.

Exceptions:

  1. Skylights are exempt from SHGC requirements provided the following:
    1. They have a glazing material or diffuser with a measured haze value greater than 90% when tested according to ASTM D1003.
    2. They have a skylight VT greater than 0.40.
    3. They have all general lighting in the daylight area under skylights controlled by multilevel photocontrols in accordance with Section 9.4.1.1(f).
  2. 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 is not dynamic glazing shall not be permitted.
The vertical fenestration shall comply with either (a) or (b):
  1. AW ≤ (AT)/4 and AE ≤ (AT)/4
  2. AW × SHGCW ≤ (AT × SHGCC)/4 and AE × SHGCE(AT × SHGCC)/4

where

Aw = west-oriented vertical fenestration area (oriented within 45 degrees of true west to the south and within 22.5 degrees of true west to the north in the northern hemisphere; oriented within 45 degrees of true west to the north and within 22.5 degrees of true west to the south in the southern hemisphere)
Ae = east-oriented vertical fenestration area (oriented within 45 degrees of true east to the south and within 22.5 degrees of true east to the north in the northern hemisphere; oriented within 45 degrees of true east to the north and within 22.5 degrees of true east to the south in the southern hemisphere)
AT = total vertical fenestration area
SHGCC = SHGC criteria in Tables 5.5-1 through 5.5-8 for each climate zone
SHGCE = SHGC for east-oriented fenestration that complies with Section 5.5.4.4.1
SHGCW = SHGC for west-oriented fenestration that complies with Section 5.5.4.4.1

Exceptions:

  1. Vertical fenestration that complies with Exception (3) Section 5.5.4.4.1.
  2. Buildings that have an existing building or existing permanent infrastructure within 20 ft to the south (north in the southern hemisphere) that is at least half as tall as the proposed building
  3. Buildings with shade on 75% of the west- and east-oriented vertical fenestration areas from permanent projections, existing buildings, existing permanent infrastructure, or topography at 9 a.m. and 3 p.m. on the summer solstice (June 21 in the northern hemisphere)
  4. Alterations and additions with no increase in vertical fenestration area
  5. Buildings where the west-oriented and east-oriented vertical fenestration area (as defined in Section 5.5.4.5) does not exceed 20% of the gross wall area for each of those façades, and SHGC on those facades is no greater than 90% of the criteria in Tables 5.5-1 through 5.5-8
  6. Buildings in Climate Zone 8
Where automatic daylighting controls are required in accordance with Section 9.4.1.1(e) or (f), fenestration shall have a ratio of VT divided by SHGC not less than that specified in Tables 5.5-1 through 5.5-8 for the appropriate fenestration area.

Exceptions:

  1. A light-to-solar-gain ratio (LSG) of not less than 1.25 is allowed to be used as an alternative to VT/SHGC. When using this option, the center-of-glass VT and the center-of-glass SHGC shall be determined in accordance with NFRC 300 and NFRC 301, determined by an independent laboratory or included in a database published by a government agency, and certified by the manufacturer.
  2. Fenestration not covered in the scope of the NFRC 200
  3. Enclosed spaces where the daylight area under rooftop monitors is greater than 50% of the enclosed space floor area
  4. Enclosed spaces with skylight(s) that comply with Section 5.5.4.2.3
  5. Enclosed spaces where the sidelighting effective aperture is greater than or equal to 0.15
  6. For dynamic glazing, the VT/SHGC ratio and the LSG shall be determined using the maximum VT and maximum SHGC. Dynamic glazing shall be considered separately from other fenestration, and area-weighted averaging with other fenestration that is not dynamic glazing shall not be permitted.
The building envelope complies with the standard if
  1. the proposed building satisfies the provisions of Sections 5.1, 5.4, 5.7, and 5.8 and
  2. the envelope performance factor of the proposed building is less than or equal to the envelope performance factor of the budget building.
All components of the building envelope shown on architectural drawings or installed in existing buildings shall be modeled in the proposed building design. The simulation model fenestration and opaque envelope types and area shall be consistent with the design documents. Any envelope assembly that covers less than 5% of the total area of that assembly type (e.g., exterior walls) need not be separately described, provided it is similar to an assembly being modeled. If not separately described, the area of an envelope assembly shall be added to the area of an assembly of that same type with the same orientation and thermal properties.
When the building permit being sought applies to less than the whole building, parameters relating to unmodified existing conditions or to future building components shall be identical for both the proposed envelope performance factor and the base envelope performance factor. Future building components shall meet the prescriptive requirements of Section 5.5
Envelope performance factor shall be calculated using the procedures of Normative Appendix C.
The authority having jurisdiction may require submittal of compliance documentation and supplemental information in accordance with Section 4.2.2 of this standard.
For buildings that contain spaces that will be only semiheated or unconditioned, and compliance is sought using the semiheated envelope criteria, such spaces shall be clearly indicated on the floor plans that are submitted for review.
Test results required in Section 5.8.2.5 for skylight glazing or diffusers shall be included with construction documents submitted with each application for a permit.
The rated R-value shall be clearly identified by an identification mark applied by the manufacturer to each piece of building envelope insulation.

Exception: When insulation does not have such an identification mark, the installer of such insulation shall provide a signed and dated certification for the installed insulation listing the type of insulation, the manufacturer, the rated R-value, and, where appropriate, the initial installed thickness, the settled thickness, and the coverage area.

Insulation materials shall be installed in accordance with manufacturers' recommendations and in such a manner as to achieve rated R-value of insulation.

Exception: Where metal-building roof and metal-building wall insulation is compressed between the roof or wall skin and the structure

Open-blown or poured loose-fill insulation shall not be used in attic roof spaces when the slope of the ceiling is more than three in twelve.
When eave vents are installed, baffling of the vent openings shall be provided to deflect the incoming air above the surface of the insulation.
Insulation shall be installed in a permanent manner in substantial contact with the inside surface in accordance with manufacturers' recommendations for the framing system used. Flexible batt insulation installed in floor cavities shall be supported in a permanent manner by supports no greater than 24 in. on center.

Exception: Insulation materials that rely on air spaces adjacent to reflective surfaces for their rated performance.

Lighting fixtures; heating, ventilating, and air-conditioning equipment, including wall heaters, ducts, and plenums; and other equipment shall not be recessed in such a manner as to affect the insulation thickness unless
  1. the total combined area affected (including necessary clearances) is less than 1% of the opaque area of the assembly,
  2. the entire roof, wall, or floor is covered with insulation to the full depth required, or
  3. the effects of reduced insulation are included in calculations using an area-weighted-average method and compressed insulation values obtained from Table A9.4-2.

In all cases, air leakage through or around the recessed equipment to the conditioned space shall be limited in accordance with Section 5.4.3.

Exterior insulation shall be covered with a protective material to prevent damage from sunlight, moisture, landscaping operations, equipment maintenance, and wind.
In attics and mechanical rooms, a way to access equipment that prevents damaging or compressing the insulation shall be provided.
Foundation vents shall not interfere with the insulation.
Insulation materials in ground contact shall have a water absorption rate no greater than 0.3% when tested in accordance with ASTM C272.
The roof insulation shall not be installed on a suspended ceiling with removable ceiling panels.
Insulation shall extend over the full component area to the required rated R-value of insulation, U-factor, C-factor, or F-factor, unless otherwise allowed in Section 5.8.1.
Where two or more layers of rigid insulation board are used in a construction assembly, the edge joints between each layer of boards shall be staggered.
The U-factor, SHGC, VT, and air leakage rate for all manufactured fenestration products shall be determined by a laboratory accredited by a nationally recognized accreditation organization, such as the National Fenestration Rating Council.
All manufactured and site-built fenestration and door products shall be labeled, or a signed and dated certificate shall be provided, by the manufacturer, listing the U-factor, SHGC, VT, and air leakage rate.

Exception: Doors with less than 25% glazing are not required to list SHGC and VT.

U-factors shall be determined in accordance with NFRC 100. U-factors for skylights shall be determined for a slope of 20 degrees above the horizontal.

Exceptions:

  1. U-factors from Section A8.1 shall be an acceptable alternative for determining compliance with the U-factor criteria for skylights. Where credit is being taken for a low-emissivity coating, the emissivity of the coating shall be determined in accordance with NFRC 300. Emissivity shall be verified and certified by the manufacturer.
  2. U-factors from Section A8.2 shall be an acceptable alternative for determining compliance with the U-factor criteria for vertical fenestration.
  3. U-factors from Section A7 shall be an acceptable alternative for determining compliance with the U-factor criteria for opaque doors.
  4. For garage doors, ANSI/DASMA105 shall be an acceptable alternative for determining U-factors.
SHGC for the overall fenestration area shall be determined in accordance with NFRC 200.

Exceptions:

  1. Shading coefficient (SC) of the center-of-glass multiplied by 0.86 shall be an acceptable alternative for determining compliance with the SHGC requirements for the overall fenestration area. SC shall be determined using a spectral data file determined in accordance with NFRC 300. SC shall be verified and certified by the manufacturer.
  2. SHGC of the center-of-glass shall be an acceptable alternative for determining compliance with the SHGC requirements for the overall fenestration area. SHGC shall be determined using a spectral data file determined in accordance with NFRC 300. SHGC shall be verified and certified by the manufacturer.
  3. SHGC from Section A8.1 shall be an acceptable alternative for determining compliance with the SHGC criteria for skylights. Where credit is being taken for a low-emissivity coating, the emissivity of the coating shall be determined in accordance with NFRC 300. Emissivity shall be verified and certified by the manufacturer.
  4. SHGC from Section A8.2 shall be an acceptable alternative for determining compliance with the SHGC criteria for vertical fenestration.
VT shall be determined in accordance with NFRC 200. VT shall be verified and certified by the manufacturer.

Exceptions: For skylights whose transmittances are not within the scope of NFRC 200, their transmittance shall be the solar photometric transmittance of the skylight glazing material(s) determined in accordance with ASTM E972.

 

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