CODES

ADOPTS WITH AMENDMENTS:

International Energy Conservation Code 2012 (IECC 2012)

Important Disclaimer

2015 Minnesota Building Code Administration

2015 Minnesota Residential Energy Code

Chapter 1 [Re] Scope and Administration

Chapter 2 [Re] Definitions

Chapter 3 [Re] General Requirements

Chapter 4 [Re] Residential Energy Efficiency

Chapter 5 Referenced Standards

2015 Minnesota Commercial Energy Code

Chapter 1 [Ce] Scope and Administration

Chapter 2 [Ce] Definitions

Chapter 3 [Ce] General Requirements

Chapter 4 [Ce] Commercial Energy Efficiency

Chapter 5 Referenced Standards

Normative Appendix A

Normative Appendix B—building Envelope Climate Criteria

Normative Appendix C Methodology for Building Envelope Trade-Off Option in Subsection 5.6

Normative Appendix D Climatic Data

Informative Appendix E Informative References

Informative Appendix F Addenda Description Information

Normative Appendix G Performance Rating Method

The requirements contained in this chapter are applicable to commercial buildings, or portions of commercial buildings.
Commercial buildings shall comply with one of the following:

1. The requirements of ANSI/ASHRAE/IESNA 90.1.

2. The requirements of Sections C402, C403, C404 and C405. In addition, commercial buildings shall comply with either Section C406.2, C406.3 or C406.4.

3. The requirements of Section C407, C402.4, C403.2, C404, C405.2, C405.3, C405.4, C405.6 and C405.7. The building energy cost shall be equal to or less than 85 percent of the standard reference design building.

Additions, alterations and repairs to existing buildings shall comply with one of the following:

1. Sections C402, C403, C404 and C405; or

2. ANSI/ASHRAE/IESNA 90.1.

Heating commercial parking facilities is prohibited in accordance with Minnesota Statutes, Section 216C.20, subdivision 3.
Once-through water use permits are prohibited in accordance with Minnesota Statutes, Section 103G.271, subdivision 5.
Parking lot lighting is regulated by the Minnesota Department of Transportation in Minnesota Rules, Chapter 8885.
The building thermal envelope shall comply with Section C402.1.1. Section C402.1.2 shall be permitted as an alternative to the R-values specified in Section C402.1.1.
The building thermal envelope shall meet the requirements of Tables C402.2 and C402.3 based on the climate zone specified in Chapter 3. Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the R-values from the “Group R” column of Table C402.2. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the R-values from the “All other” column of Table C402.2. Buildings with a vertical fenestration area or skylight area that exceeds that allowed in Table C402.3 shall comply with the building envelope provisions of ANSI/ASHRAE/IESNA 90.1.
An assembly with a U-factor, C-factor, or F-factor equal or less than that specified in Table C402.1.2 shall be permitted as an alternative to the R-value in Table C402.2. Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the U-factor, C-factor, or F-factor from the “Group R” column of Table C402.1.2. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the U-factor, C-factor or F-factor from the “All other” column of Table C402.1.2.

TABLE C402.1.2 OPAQUE THERMAL ENVELOPE ASSEMBLY REQUIREMENTSa

CLIMATE ZONE1234 EXCEPT MARINE5 AND MARINE 4678
All otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup R
Roofs
Insulation entirely
above deck
U-0.048U-0.048U-0.048U-0.048U-0.048U-0.048U-0.039U-0.039U-0.039U-0.039U-0.032U-0.032U-0.028U-0.028U-0.028U-0.028
Metal buildingsU-0.044U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.031U-0.031U-0.029U-0.029U-0.029U-0.029
Attic and otherU-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.021U-0.021U-0.021U-0.021U-0.021U-0.021U-0.021
Walls, Above Grade
MassU-0.142U-0.142U-0.142U-0.123U-0.110U-0.104U-0.104U-0.090U-0.078U-0.078U-0.078U-0.071U-0.061U-0.061U-0.061U-0.061
Metal buildingU-0.079U-0.079U-0.079U-0.079U-0.079U-0.052U-0.052U-0.052U-0.052U-0.052U-0.052U-0.052U-0.052U-0.039U-0.052U-0.039
Metal framedU-0.077U-0.077U-0.077U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.057U-0.064U-0.052U-0.045U-0.045
Wood framed and
other
U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.051U-0.051U-0.051U-0.051U-0.036U-0.036
Walls, Below Grade
Below-grade wallb C-1.140C-1.140C-1.140C-1.140C-1.140C-1.140C-0.119C-0.119C-0.119C-0.119C-0.119C-0.119C-0.092C-0.092C-0.092C-0.092
Floors
MassU-0.322U-0.322U-0.107U-0.087U-0.076U-0.076U-0.076U-0.074U-0.074U-0.064U-0.064U-0.057U-0.055U-0.051U-0.055U-0.051
Joist/framingU-0.066U-0.066U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033
Slab-on-Grade Floors
Unheated slabsF-0.73F-0.73F-0.73F-0.73F-0.73F-0.73F-0.54F-0.54F-0.54F-0.54F-0.54F-0.52F-0.40F-0.40F-0.40F-0.40
Heated slabsF-0.70F-0.70F-0.70F-0.70F-0.70F-0.70F-0.65F-0.65F-0.58F-0.58F-0.58F-0.58F-0.55F-0.55F-0.55F-0.55
a. Use of opaque assembly U-factors, C-factors, and F-factors from ANSI/ASHRAE/IESNA 90.1 Appendix A shall be permitted, provided the construction complies with the applicable construction details from ANSI/ASHRAE/IESNA 90.1 Appendix A .
b. Where heated slabs are below grade, below-grade walls shall comply with the F-factor requirements for heated slabs.
Opaque assemblies shall comply with Table C402.2. Where two or more layers of continuous insulation board are used in a construction assembly, the continuous insulation boards shall be installed in accordance with Section C303.2. If the continuous insulation board manufacturer’s installation instructions do not address installation of two or more layers, the edge joints between each layer of continuous insulation boards shall be staggered.

TABLE C402.2 OPAQUE THERMAL ENVELOPE REQUIREMENTSa

CLIMATE ZONE1234 EXCEPT MARINE5 AND MARINE 4678
All OtherGroup RAll OtherGroup RAll OtherGroup RAll OtherGroup RAll OtherGroup RAll OtherGroup RAll OtherGroup RAll OtherGroup R
Roofs
Insulation entirely above deckR-20ciR-20ciR-20ciR-20ciR-20ciR-20ciR-25ciR-25ciR-25ciR-25ciR-30ciR-30ciR-35ciR-35ciR-35ciR-35ci
Metal buildings (with R-5 thermal blocks)a, bR-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-25 +
R-11 LS
R-25 +
R-11 LS
R-30 +
R-11 LS
R-30 +
R-11 LS
R-30 +
R-11 LS
R-30 +
R-11 LS
Attic and otherR-38R-38R-38R-38R-38R-38R-38R-38R-38R-49R-49R-49R-49R-49 R-49R-49
Walls, Above Grade
MassR-5.7ciR-5.7ciR-5.7ciR-7.6ciR-7.6ciR-9.5ciR-9.5ciR-11.4ciR-11.4ciR-13.3ciR-13.3ciR-15.2ciR-15.2ciR-15.2ciR-25ciR-25ci
Metal buildingR-13+
R-6.5ci
R-13 +
R-6.5ci
R13 +
R-6.5ci
R-13 +
R-13ci
R-13 +
R-6.5ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13+
R-19.5ci
R-13 +
R-13ci
R-13+
R-19.5ci
Metal framedR-13 +
R-5ci
R-13 +
R-5ci
R-13 +
R-5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-15.6ci
R-13 +
R-7.5ci
R-13+ R17.5ci
Wood framed and otherR-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-3.8ci or R-20
R-13 +
R-7.5ci or R-20 +
R-3.8ci
R-13 +
R-7.5ci or R-20 +
R-3.8ci
R-13 +
R-7.5ci or R-20 +
R-3.8ci
R-13 +
R-7.5ci or R-20 +
R-3.8ci
R-13 +
R-7.5ci or R-20 +
R-3.8ci
R-13 +
R-15.6ci or R-20 + R-10ci
R-13 +
R-15.6ci or R-20 + R-10ci
Walls, Below Grade
Below-grade walldNRNRNRNRNRNRR-7.5ciR-7.5ciR-7.5ciR-7.5ciR-7.5ciR-7.5ciR-10ciR-10ciR-10ciR-12.5ci
Floors
MassNRNRR-6.3ciR-8.3ciR-10ciR-10ciR-10ciR-10.4ciR-10ciR-12.5ciR-12.5ciR-12.5ciR-15ciR-16.7ciR-15ciR-16.7ci
Joist/framingNRNRR-30R-30R-30R-30 R-30R-30R-30R-30R-30R-30eR-30eR-30eR-30eR-30e
Slab-on-Grade Floors
Unheated slabsNRNRNRNRNRNRR-10 for 24? belowR-10 for 24? belowR-10 for 24? belowR-10 for 24? belowR-10 for 24? belowR-15 for 24? belowR-15 for 24? belowR-15 for 24? belowR-15 for 24?belowR-20 for 24? below
Heated slabsdR-7.5 for 12? belowR-7.5 for 12? belowR-7.5 for 12? belowR-7.5 for 12? belowR-10 for 24? belowR-10 for 24? belowR-15 for 24? belowR-15 for 24? belowR-15 for 36? belowR-15 for 36? belowR-15 for 36? belowR-20 for 48? belowR-20 for 24? belowR-20 for 48?belowR-20 for 48? belowR-20 for 48? below
Opaque Doors
SwingingU-0.61U-0.61U-0.61U-0.61U-0.61U-0.61U-0.61U-0.61U-0.37U-0.37U-0.37U-0.37U-0.37U-0.37U-0.37U-0.37
Roll-up or slidingR-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75
For SI: 1 inch = 25.4 mm. ci = Continuous insulation. NR = No requirement.
LS = Liner System—A continuous membrane installed below the purlins and uninterrupted by framing members. Uncompressed, unfaced insulation rests on top of the membrane between the purlins.
a. Assembly descriptions can be found in ANSI/ASHRAE/IESNA Appendix A .
b. Where using R-value compliance method, a thermal spacer block shall be provided, otherwise use the U-factor compliance method in Table C402.1.2.
c. R-5.7ci is allowed to be substituted with concrete block walls complying with ASTM C90, ungrouted or partially grouted at 32 inches or less on center vertically and 48 inches or less on center horizontally, with ungrouted cores filled with materials having a maximum thermal conductivity of 0.44 Btu-in/h-f2 °F.
d. Where heated slabs are below grade, below-grade walls shall comply with the exterior insulation requirements for heated slabs.
e. Steel floor joist systems shall be insulated to R-38.
The minimum thermal resistance (R-value) of the insulating material installed either between the roof framing or continuously on the roof assembly shall be as specified in Table C402.2, based on construction materials used in the roof assembly. Skylight curbs shall be insulated to the level of roofs with insulation entirely above deck or R-5, whichever is less.
Exceptions:

1. Continuously insulated roof assemblies where the thickness of insulation varies 1 inch (25 mm) or less and where the area-weighted U-factor is equivalent to the same assembly with the R-value specified in Table C402.2.

2. Unit skylight curbs included as a component of an NFRC 100 rated assembly shall not be required to be insulated.

Insulation installed on a suspended ceiling with removable ceiling tiles shall not be considered part of the minimum thermal resistance of the roof insulation.
Low-sloped roofs, with a slope less than 2 units vertical in 12 horizontal, directly above cooled conditioned spaces in Climate Zones 1, 2, and 3 shall comply with one or more of the options in Table C402.2.1.1.
Exceptions: The following roofs and portions of roofs are exempt from the requirements in Table C402.2.1.1:

1. Portions of roofs that include or are covered by:

1.1. Photovoltaic systems or components.

1.2. Solar air or water heating systems or components.

1.3. Roof gardens or landscaped roofs.

1.4. Above-roof decks or walkways.

1.5. Skylights.

1.6. HVAC systems, components, and other opaque objects mounted above the roof.

2. Portions of roofs shaded during the peak sun angle on the summer solstice by permanent features of the building, or by permanent features of adjacent buildings.

3. Portions of roofs that are ballasted with a minimum stone ballast of 17 pounds per square foot (psf) (74 kg/m2) or 23 psf (117 kg/m2) pavers.

4. Roofs where a minimum of 75 percent of the roof area meets a minimum of one of the exceptions above.

TABLE C402.2.1.1 MINIMUM ROOF REFLECTANCE AND EMITTANCE OPTIONSa

Three-year aged solar reflectanceb of 0.55 and three-year aged thermal emittancec of 0.75
Initial solar reflectanceb of 0.70 and initial thermal emittancec of
0.75
Three-year-aged solar reflectance indexd of 64
Initial solar reflectance indexd of 82
a. The use of area-weighted averages to meet these requirements shall be permitted. Materials lacking initial tested values for either solar reflectance or thermal emittance, shall be assigned both an initial solar reflectance of 0.10 and an initial thermal emittance of 0.90. Materials lacking three-year aged tested values for either solar reflectance or thermal emittance shall be assigned both a three-year aged solar reflectance of 0.10 and a three-year aged thermal emittance of 0.90.
b. Solar reflectance tested in accordance with ASTM C1549, ASTM E903 or ASTM E1918.
c. Thermal emittance tested in accordance with ASTM C1371 or ASTM E408.
d. Solar reflectance index (SRI) shall be determined in accordance with ASTM E1980 using a convection coefficient of 2.1 Btu/h × ft2 ×°F (12W/m2 × K). Calculation of aged SRI shall be based on aged tested values of solar reflectance and thermal emittance. Calculation of initial SRI shall be based on initial tested values of solar reflectance and thermal emittance.
For roof replacement on an existing building where the insulation is entirely above the deck and where the roof slope is less than two units vertical in 12 units horizontal, the insulation shall conform to the energy conservation requirements specified in Table C402.2, Opaque Thermal Envelope Requirements.
Exception: Where the required R-value cannot be provided because of the thickness limitations that occur with the existing rooftop conditions, including heating, ventilation and air-conditioning equipment, low door or glazing heights, parapet heights, or proper roof flashing heights, the maximum thickness of insulation compatible with the available space and existing rooftop conditions shall be installed.
Walls associated with the building envelope shall be classified in accordance with Section C402.2.2.1 or C402.2.2.2.
Above-grade walls are those walls covered by Section C402.2.3 on the exterior of the building and completely above grade or walls that are more than 15 percent above grade.
Below-grade walls covered by Section C402.2.4 are basement or first-story walls associated with the exterior of the building that are at least 85 percent below grade.
The minimum thermal resistance (R-value) of the insulating materials installed in the wall cavity between the framing members and continuously on the walls shall be as specified in Table C402.2, based on framing type and construction materials used in the wall assembly. The R-value of integral insulation installed in concrete masonry units (CMU) shall not be used in determining compliance with Table C402.2.
“Mass walls” shall include walls weighing not less than:

1. 35 psf (170 kg/m2) of wall surface area; or

2. 25 psf (120 kg/m2) of wall surface area if the material weight is not more than 120 pounds per cubic foot (pcf) (1900 kg/m3).

The minimum thermal resistance (R-value) of the insulating material installed in, or continuously on, the below-grade walls shall be as specified in Table C402.2, and shall extend to a depth of 10 feet (3048 mm) below the outside finished ground level, or to the level of the floor, whichever is less.
The minimum thermal resistance (R-value) of the insulating material installed either between the floor framing or continuously on the floor assembly shall be as specified in Table C402.2, based on construction materials used in the floor assembly.
“Mass floors” shall include floors weighing not less than:

1. 35 psf (170 kg/m2) of floor surface area; or

2. 25 psf (120 kg/m2) of floor surface area if the material weight is not more than 12 pcf (1,900 kg/m3).

Where the slab on grade is in contact with the ground, the minimum thermal resistance (R-value) of the insulation around the perimeter of unheated or heated slab-on-grade floors shall be as specified in Table C402.2. The insulation shall be placed on the outside of the foundation or on the inside of the foundation wall. The insulation shall extend downward from the top of the slab for a minimum distance as shown in the table or to the top of the footing, whichever is less, or downward to at least the bottom of the slab and then horizontally to the interior or exterior for the total distance shown in the table. Insulation extending away from the building shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil.
Exception: Where the slab-on-grade floor is greater than 24 inches (61 mm) below the finished exterior grade, perimeter insulation is not required.
Opaque doors (doors having less than 50 percent glass area) shall meet the applicable requirements for doors as specified in Table C402.2 and be considered as part of the gross area of above-grade walls that are part of the building envelope.
Radiant panels, and associated U-bends and headers, designed for sensible heating of an indoor space through heat transfer from the thermally effective panel surfaces to the occupants or indoor space by thermal radiation and natural convection and the bottom surfaces of floor structures incorporating radiant heating shall be insulated with a minimum of R-3.5 (0.62 m2/K × W).
Fenestration shall comply with Table C402.3. Automatic daylighting controls specified by this section shall comply with Section C405.2.2.3.2.

TABLE C402.3 BUILDING ENVELOPE REQUIREMENTS: FENESTRATION

CLIMATE ZONE1234 EXCEPT MARINE5 AND MARINE 4678
Vertical fenestration
U-factor
Fixed fenestration0.500.500.460.380.380.360.290.29
Operable fenestration0.650.650.600.450.450.430.370.37
Entrance doors1.100.830.770.770.770.770.770.77
SHGC
SHGC0.250.250.250.400.400.400.450.45
Skylights
U-factor0.750.650.550.500.500.500.500.50
SHGC0.350.350.350.400.400.40NRNR
NR = No requirement.
The vertical fenestration area (not including opaque doors and opaque spandrel panels) shall not exceed 30 percent of the gross above-grade wall area. The skylight area shall not exceed 3 percent of the gross roof area.
In Climate Zones 1 through 6, a maximum of 40 percent of the gross above-grade wall area shall be permitted to be vertical fenestration, provided:

1. No less than 50 percent of the conditioned floor area is within a daylight zone;

2. Automatic daylighting controls are installed in daylight zones; and

3. Visible transmittance (VT) of vertical fenestration is greater than or equal to 1.1 times solar heat gain coefficient (SHGC).

Exception: Fenestration that is outside the scope of NFRC 200 is not required to comply with Item 3.
The skylight area shall be permitted to be a maximum of 5 percent of the roof area provided automatic daylighting controls are installed in daylight zones under skylights.
In an enclosed space greater than 10,000 square feet (929 m2), directly under a roof with ceiling heights greater than 15 feet (4572 mm), and used as an office, lobby, atrium, concourse, corridor, storage, gymnasium/exercise center, convention center, automotive service, manufacturing, non-refrigerated warehouse, retail store, distribution/sorting area, transportation, or workshop, the total daylight zone under skylights shall be not less than half the floor area and shall provide a minimum skylight area to daylight zone under skylights of either:

1. Not less than 3 percent with a skylight VT of at least 0.40; or

2. Provide a minimum skylight effective aperture of at least 1 percent determined in accordance with Equation 4-1.

(Equation 4-1)
where:
Skylight area= Total fenestration area of
skylights.
Skylight VT= Area weighted average visible
transmittance of skylights.
WF= Area weighted average well
factor, where well factor is 0.9
if light well depth is less than 2
feet (610 mm), or 0.7 if light
well depth is 2 feet (610 mm) or
greater.
Light well depth = Measure vertically from the
underside of the lowest point of
the skylight glazing to the ceiling
plane under the skylight.

Exception: Skylights above daylight zones of enclosed spaces are not required in:

1. Buildings in climate zones 6 through 8.

2. Spaces where the designed general lighting power densities are less than 0.5 W/ft2 (5.4 W/m2).

3. Areas where it is documented that existing structures or natural objects block direct beam sunlight on at least half of the roof over the enclosed area for more than 1,500 daytime hours per year between 8 am and 4 pm.

4. Spaces where the daylight zone under rooftop monitors is greater than 50 percent of the enclosed space floor area.

All lighting in the daylight zone shall be controlled by multilevel lighting controls that comply with Section C405.2.2.3.3.
Exception: Skylights above daylight zones of enclosed spaces are not required in:

1. Buildings in Climate Zones 6 through 8.

2. Spaces where the designed general lighting power densities are less than 0.5 W/ft2 (5.4 W/m2).

3. Areas where it is documented that existing structures or natural objects block direct beam sunlight on at least half of the roof over the enclosed area for more than 1,500 daytime hours per year between 8 am and 4 pm.

4. Spaces where the daylight zone under rooftop monitors is greater than 50 percent of the enclosed space floor area.

Skylights in office, storage, automotive service, manufacturing, nonrefrigerated warehouse, retail store, and distribution/sorting area spaces shall have a glazing material or diffuser with a measured haze factor greater than 90 percent when tested in accordance with ASTM D1003.
Exception: Skylights designed to exclude direct sunlight entering the occupied space by the use of fixed or automated baffles, or the geometry of skylight and light well need not comply with Section C402.3.2.2.
For vertical fenestration, the maximum U-factor and solar heat gain coefficient (SHGC) shall be as specified in Table C402.3, based on the window projection factor. For skylights, the maximum U-factor and solar heat gain coefficient (SHGC) shall be as specified in Table C402.3.
The window projection factor shall be determined in accordance with Equation 4-2.
PF = A/B(Equation 4-2)
where:
PF= Projection factor (decimal).
A= Distance measured horizontally from the furthest
continuous extremity of any overhang, eave, or
permanently attached shading device to the vertical
surface of the glazing.
B= Distance measured vertically from the bottom of the
glazing to the underside of the overhang, eave, or
permanently attached shading device.

Where different windows or glass doors have different PF values, they shall each be evaluated separately.

Where the fenestration projection factor for a specific vertical fenestration product is greater than or equal to 0.2, the required maximum SHGC from Table C402.3 shall be adjusted by multiplying the required maximum SHGC by the multiplier specified in Table C402.3.3.1 corresponding with the orientation of the fenestration product and the projection factor.

TABLE C402.3.3.1 SHGC ADJUSTMENT MULTIPLIERS

PROJECTION FACTORORIENTED WITHIN 45
DEGREES OF TRUE NORTH
ALL OTHER
ORIENTATION
0.2 ? PF < 0.51.11.2
PF ?0.51.21.6
In Climate Zones 1, 2 and 3, vertical fenestration entirely located not less than 6 feet (1729 mm) above the finished floor shall be permitted a maximum SHGC of 0.40.
In Climate Zones 1 through 6, skylights shall be permitted a maximum SHGC of 0.60 where located above daylight zones provided with automated daylighting controls.
Where skylights are installed above daylight zones provided with automatic daylighting controls, a maximum U-factor of 0.9 shall be permitted in Climate Zones 1 through 3; and a maximum U-factor of 0.75 shall be permitted in Climate Zones 4 through 8.
For compliance with Section C402.3.3, the SHGC for dynamic glazing shall be determined using the manufacturer’s lowest-rated SHGC, and the VT/SHGC ratio 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.
An area-weighted average shall be permitted to satisfy the U-factor requirements for each fenestration product category listed in Table C402.3. Individual fenestration products from different fenestration product categories listed in Table C402.3 shall not be combined in calculating area-weighted average U-factor.
The thermal envelope of buildings shall comply with Sections C402.4.1 through C402.4.8.
A continuous air barrier shall be provided throughout the building thermal envelope. The air barriers shall be permitted to be located on the inside or outside of the building envelope, located within the assemblies composing the envelope, or any combination thereof. The air barrier shall comply with Sections C402.4.1.1 and C402.4.1.2.
Exception: Air barriers are not required in buildings located in Climate Zones 1, 2 and 3.
The continuous air barrier shall be constructed to comply with the following:

1. The air barrier shall be continuous for all assemblies that are the thermal envelope of the building and across the joints and assemblies.

2. Air barrier joints and seams shall be sealed, including sealing transitions in places and changes in materials. Air barrier penetrations shall be sealed in accordance with Section C402.4.2. The joints and seals shall be securely installed in or on the joint for its entire length so as not to dislodge, loosen, or otherwise impair its ability to resist positive and negative pressure from wind, stack effect, and mechanical ventilation.

3. Recessed lighting fixtures shall comply with Section C402.4.8. Where similar objects are installed that penetrate the air barrier, provisions shall be made to maintain the integrity of the air barrier.

A continuous air barrier for the opaque building envelope shall comply with Section C402.4.1.2.1, C402.4.1.2.2, or C402.4.1.2.3.
Materials with an air permeability no greater than 0.004 cfm/ft2 (0.02 L/s • m2) under a pressure differential of 0.3 inches water gauge (w.g.) (75 Pa) when tested in accordance with ASTM E2178 shall comply with this section. Materials in Items 1 through 15 shall be deemed to comply with this section provided joints are sealed and materials are installed as air barriers in accordance with the manufacturer’s instructions.

1. Plywood with a thickness of not less than 3/8 inch (10 mm).

2. Oriented strand board having a thickness of not less than 3/8 inch (10 mm).

3. Extruded polystyrene insulation board having a thickness of not less than 1/2 inch (12 mm).

4. Foil-back polyisocyanurate insulation board having a thickness of not less than 1/2 inch (12 mm).

5. Closed cell spray foam a minimum density of 1.5 pcf (2.4 kg/m3) having a thickness of not less than 11/2 inches (36 mm).

6. Open cell spray foam with a density between 0.4 and 1.5 pcf (0.6 and 2.4 kg/m3) and having a thickness of not less than 4.5 inches (113 mm).

7. Exterior or interior gypsum board having a thickness of not less than 1/2 inch (12 mm).

8. Cement board having a thickness of not less than 1/2 inch (12 mm).

9. Built up roofing membrane.

10. Modified bituminous roof membrane.

11. Fully adhered single-ply roof membrane.

12. A Portland cement/sand parge, or gypsum plaster having a thickness of not less than 5/8 inch (16 mm).

13. Cast-in-place and precast concrete.

14. Fully grouted concrete block masonry.

15. Sheet steel or aluminum.

Assemblies of materials and components with an average air leakage not to exceed 0.04 cfm/ft2 (0.2 L/s • m2) under a pressure differential of 0.3 inches of water gauge (w.g.)(75 Pa) when tested in accordance with ASTM E2357, ASTM E1677 or ASTM E283 shall comply with this section. Assemblies listed in Items 1 and 2 shall be deemed to comply provided joints are sealed and requirements of Section C402.4.1.1 are met.

1. Concrete masonry walls coated with one application either of block filler and two applications of a paint or sealer coating;

2. A Portland cement/sand parge, stucco or plaster minimum 1/2 inch (12 mm) in thickness.

The completed building shall be tested and the air leakage rate of the building envelope shall not exceed 0.40 cfm/ft2 at a pressure differential of 0.3 inches water gauge (2.0 L/s • m2 at 75 Pa) in accordance with ASTM E779 or an equivalent method approved by the code official.
Penetrations of the air barrier and paths of air leakage shall be caulked, gasketed or otherwise sealed in a manner compatible with the construction materials and location. Joints and seals shall be sealed in the same manner or taped or covered with a moisture vapor-permeable wrapping material. Sealing materials shall be appropriate to the construction materials being sealed. The joints and seals shall be securely installed in or on the joint for its entire length so as not to dislodge, loosen or otherwise impair its ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation.
The air leakage of fenestration assemblies shall meet the provisions of Table C402.4.3. Testing shall be in accordance with the applicable reference test standard in Table C402.4.3 by an accredited, independent testing laboratory and labeled by the manufacturer.
Exceptions:

1. Field-fabricated fenestration assemblies that are sealed in accordance with Section C402.4.1.

2. Fenestration in buildings that comply with Section C402.4.1.2.3 are not required to meet the air leakage requirements in Table C402.4.3.

TABLE C402.4.3 MAXIMUM AIR INFILTRATION RATE
FOR FENESTRATION ASSEMBLIES

FENESTRATION ASSEMBLYMAXIMUM
RATE (CFM/FT2)
TEST PROCEDURE
Windows0.20 aAAMA/WDMA/
CSA101/I.S.2/A440
or
NFRC 400
Sliding doors0.20 a
Swinging doors0.20 a
Skylights – with condensation
weepage openings
0.30
Skylights – all other0.20 a
Curtain walls0.06NFRC 400
or
ASTM E 283 at 1.57 psf
(75 Pa)
Storefront glazing0.06
Commercial glazed
swinging entrance doors
1.00
Revolving doors1.00
Garage doors0.40ANSI/DASMA 105,
NFRC 400, or
ASTM E 283 at 1.57 psf
(75 Pa)
Rolling doors1.00
For SI: 1 cubic foot per minute = 0.47L/s, 1 square foot = 0.093 m2.
a. The maximum rate for windows, sliding and swinging doors, and skylights is permitted to be 0.3 cfm per square foot of fenestration or door area when tested in accordance with AAMA/WDMA/CSA101/I.S.2/A440 at 6.24 psf (300 Pa).
Doors and access openings from conditioned space to shafts, chutes stairways and elevator lobbies shall either meet the requirements of Section C402.4.3 or shall be gasketed, weatherstripped or sealed.
Exception: Door openings required to comply with Section 715 or 715.4 of the International Building Code; or doors and door openings required by the International Building Code to comply with UL 1784 shall not be required to comply with Section C402.4.4.
Stairway enclosures and elevator shaft vents and other outdoor air intakes and exhaust openings integral to the building envelope shall be provided with dampers in accordance with Sections C402.4.5.1 and C402.4.5.2.
Stairway and shaft vents shall be provided with Class I motorized dampers with a maximum leakage rate of 4 cfm/ft2 (20.3 L/s m2) at 1.0 inch water gauge (w.g.) (249 Pa) when tested in accordance with AMCA 500D.
Controls for operating stairway and shaft vents shall be provided in accordance with Minnesota Rules, Chapter 1305.
Outdoor air supply and exhaust openings shall be provided with Class IA motorized dampers with a maximum leakage rate of 4 cfm/ft2 (20.3 L/s m2) at 1.0 inch water gauge (w.g.) (249 Pa) when tested in accordance with AMCA 500D.
Exceptions:

1. For exhaust and relief dampers in buildings less than three stories in height above grade plane or, where the design outdoor air intake or exhaust capacity does not exceed 300 cfm (141 L/s), gravity (nonmotorized) dampers having a maximum leakage rate of 20 cfm/ft2 (101.6 L/s m2) at 1.0 inch water gauge (w.g.) (249 Pa) when tested in accordance with AMCA 500D are permitted to be used. Gravity (nonmotorized) dampers for ventilation air intakes shall be protected from direct exposure to wind.

2. Nonmotorized dampers smaller than 24 inches (610 mm) in either dimension shall be permitted to have a leakage of 40 cfm/ft2 (203.2 L/s m2) at 1.0 inch water gauge (w.g.) (249 Pa) when tested in accordance with AMCA 500D.

3. Dampers for exhaust ducts 8 inches (203 mm) in diameter and smaller shall be permitted without being tested in accordance with AMCA 500D if equipped with a spring-loaded backdraft damper and a weather hood at the point of discharge.

Cargo doors and loading dock doors shall be equipped with weatherseals to restrict infiltration when vehicles are parked in the doorway.
All building entrances 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. The installation of one or more revolving doors in the building entrance shall not eliminate the requirement that a vestibule be provided on any doors adjacent to revolving doors.
Exceptions:

1. Buildings in Climate Zones 1 and 2.

2. Doors not intended to be used by the public, such as doors to mechanical or electrical equipment rooms, or intended solely for employee use.

3. Doors opening directly from a sleeping unit or dwelling unit.

4. Doors that open directly from a space less than 3,000 square feet (298 m2) in area.

5. Revolving doors.

6. Doors used primarily to facilitate vehicular movement or material handling and adjacent personnel doors.

Recessed luminaires installed in the building thermal envelope shall be sealed to limit air leakage between conditioned and unconditioned spaces. All recessed luminaires shall be IC-rated and labeled as having an air leakage rate or not more 2.0 cfm (0.944 L/s) when tested in accordance with ASTM E283 at a 1.57 psf (75 Pa) pressure differential. All recessed luminaires shall be sealed with a gasket or caulk between the housing and interior wall or ceiling covering.
Mechanical systems and equipment serving the building heating, cooling or ventilating needs shall comply with Section C403.2 (referred to as the mandatory provisions) and either:

1. Section C403.3 (Simple systems); or

2. Section C403.4 (Complex systems).

Mechanical systems and equipment serving the building heating, cooling or ventilating needs shall comply with Sections C403.2.1 through C403.2.11.
Design loads shall be determined in accordance with the procedures described in ANSI/ASHRAE/ACCA Standard 183, Peak Cooling and Heating Load Calculations in Buildings Except Low-Rise Residential Buildings, and by using the design parameters specified in Table C403.2.1.

TABLE C403.2.1 CLIMATIC DATA DESIGN CONDITIONS

CITYSUMMER Db/Wb °FWINTER Db °F
Aitkin82/72-24
Albert Lea85/72-15
Alexandria86/70-21
Bemidji84/68-24
Cloquet82/68-20
Crookston84/70-27
Duluth81/67-20
Ely82/68-29
Eveleth82/68-26
Faribault86/73-16
Fergus Falls86/71-21
Grand Rapids81/67-23
Hibbing82/68-19
International Falls83/67-28
Litchfield85/71-18
Little Falls86/71-20
Mankato86/72-15
Minneapolis/St. Paul88/72-15
Montevideo86/72-17
Mora84/70-21
Morris84/72-21
New Ulm87/73-15
Owatonna86/73-16
Pequot Lakes84/68-23
Pipestone85/73-15
Redwood Falls89/73-17
Rochester85/72-17
Roseau82/70-29
St. Cloud86/71-20
Thief River Falls82/68-25
Tofte75/61-14
Warroad83/67-29
Wheaton84/71-20
Willmar85/71-20
Winona88/74-13
Worthington84/71-14
Db = dry bulb temperature, degrees Fahrenheit.
Wb = wet bulb temperature, degrees Fahrenheit.
The output capacity of heating and cooling equipment and systems shall not exceed the loads calculated in accordance with Section C403.2.1. A single piece of equipment providing both heating and cooling shall satisfy this provision for one function with the capacity for the other function as small as possible, within available equipment options.
Exceptions:

1. Required standby equipment and systems provided with controls and devices that allow such systems or equipment to operate automatically only when the primary equipment is not operating.

2. Multiple units of the same equipment type with combined capacities exceeding the design load and provided with controls that have the capability to sequence the operation of each unit based on load.

3. Heating and cooling equipment sizing is permitted to be up to ten percent greater than the calculated peak heating and cooling loads to allow for building pickup and cool down after temperature setback conditions.

Equipment shall meet the minimum efficiency requirements of Tables C403.2.3(1), C403.2.3(2), C403.2.3(3), C403.2.3(4), C403.2.3(5), C403.2.3(6), C403.2.3(7) and C403.2.3(8) when tested and rated in accordance with the applicable test procedure. Plate-type liquid-to-liquid heat exchangers shall meet the minimum requirements of Table C403.2.3(9). The efficiency shall be verified through certification under an approved certification program or, if no certification program exists, the equipment efficiency ratings shall be supported by data furnished by the manufacturer. Where multiple rating conditions or performance requirements are provided, the equipment shall satisfy all stated requirements. Where components, such as indoor or outdoor coils, from different manufacturers are used, calculations and supporting data shall be furnished by the designer that demonstrates that the combined efficiency of the specified components meets the requirements herein.

TABLE C403.2.3(1) MINIMUM EFFICIENCY REQUIREMENTS:
ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS

EQUIPMENT TYPESIZE CATEGORYHEATING
SECTION TYPE
SUBCATEGORY OR
RATING CONDITION
MINIMUM EFFICIENCYTEST
PROCEDUREa
Before 6/1/2011As of 6/1/2011
Air conditioners,
air cooled
< 65,000 Btu/hbAllSplit System13.0 SEER13.0 SEERAHRI
210/240
Single Package13.0 SEER13.0 SEER
Through-the-wall
(air cooled)
? 30,000 Btu/hbAllSplit system12.0 SEER12.0 SEER
Single Package12.0 SEER12.0 SEER
Small-duct high-velocity
(air cooled)
< 65,000 Btu/hbAllSplit System10.0 SEER10.0 SEER
Air conditioners,
air cooled
? 65,000 Btu/h
and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.2 EER
11.4 IEER
11.2 EER
11.4 IEER
AHRI
340/360
All otherSplit System and
Single Package
11.0 EER
11.2 IEER
11.0 EER
11.2 IEER
? 135,000 Btu/h
and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
11.2 IEER
11.0 EER
11.2 IEER
All otherSplit System and
Single Package
10.8 EER
11.0 IEER
10.8 EER
11.0 IEER
? 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
10.0 EER
10.1 IEER
10.0 EER
10.1 IEER
All otherSplit System and
Single Package
9.8 EER
9.9 IEER
9.8 EER
9.9 IEER
? 760,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
9.7 EER
9.8 IEER
9.7 EER
9.8 IEER
All otherSplit System and
Single Package
9.5 EER
9.6 IEER
9.5 EER
9.6 IEER
Air conditioners,
water cooled
< 65,000 Btu/hbAllSplit System and
Single Package
12.1 EER
12.3 IEER
12.1 EER
12.3 IEER
AHRI
210/240
? 65,000 Btu/h
and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.5 EER
11.7 IEER
12.1 EER
12.3 IEER
AHRI
340/360
All otherSplit System and
Single Package
11.3 EER
11.5 IEER
11.9 EER
12.1 IEER
? 135,000 Btu/h
and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
11.2 IEER
12.5 EER
12.7 IEER
All otherSplit System and
Single Package
10.8 EER
11.0 IEER
12.3 EER
12.5 IEER
? 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
11.1 IEER
12.4 EER
12.6 IEER
All otherSplit System and
Single Package
10.8 EER
10.9 IEER
12.2 EER
12.4 IEER
? 760,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
11.0 EER
11.1 IEER
12.0 EER
12.4 IEER
All otherSplit System and
Single Package
10.8 EER
10.9 IEER
12.0 EER
12.2 IEER

(continued)

TABLE C403.2.3(1)—continued
MINIMUM EFFICIENCY REQUIREMENTS:
ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS

EQUIPMENT TYPESIZE CATEGORYHEATING
SECTION TYPE
SUB-CATEGORY OR
RATING CONDITION
MINIMUM EFFICIENCYTEST
PROCEDUREa
Before 6/1/2011As of 6/1/2011
Air conditioners,
evaporatively cooled
< 65,000 Btu/hbAllSplit System and
Single Package
12.1 EER
12.3 IEER
12.1 EER
12.3 IEER
AHRI
210/240
? 65,000 Btu/h
and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.5 EER
11.7 IEER
12.1 EER
12.3 IEER
AHRI
340/360
All otherSplit System and
Single Package
11.3 EER
11.5 IEER
11.9 EER
12.1 IEER
? 135,000 Btu/h
and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
11.2 IEER
12.0 EER
12.2 IEER
All otherSplit System and
Single Package
10.8 EER
11.0 IEER
11.8 EER
12.0 IEER
? 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
11.1 IEER
11.9 EER
12.1 IEER
All otherSplit System and
Single Package
10.8 EER
10.9 IEER
12.2 EER
11.9 IEER
? 760,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
10.0 EER
11.1 IEER
11.7 EER
11.9 IEER
All otherSplit System and
Single Package
10.8 EER
10.9 IEER
11.5 EER
11.7 IEER
Condensing units,
air cooled
? 135,000 Btu/h10.1 EER
11.4 IEER
10.5 EER
14.0 IEER
AHRI
365
Condensing units,
water cooled
? 135,000 Btu/h13.1 EER
13.6 IEER
13.5 EER
14.0 IEER
Condensing units,
evaporatively cooled
? 135,000 Btu/h13.1 EER
13.6 IEER
13.5 EER
14.0 IEER
For SI: 1 British thermal unit per hour = 0.2931 W.
a. Chapter 6 of the referenced standard contains a complete specification of the referenced test procedure, including the reference year version of the test procedure.
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