PERFORMANCE: Codes & Standards

IECC Climate Zone Map

2016 | 2010 | 2007 | 2004

ASHRAE Standard 90.1-2016

ASHRAE Standard 90.1-2016 is the latest version of ASHRAE 90.1 and includes substantial reduction in fenestration U-factors in all climate zones and reductions of the SHGC in most climate zones. Like all versions of the standard, its prescriptive building envelope option sets U-factor and SHGC requirements and fenestration area limits, with the vertical fenestration to no more than 40% and skylights to 3%. Other compliance options allow greater design flexibility but are more complex. Regardless of the chosen compliance option, fenestration must not exceed mandatory air leakage limits.

ASHRAE 90.1-2016 Prescriptive Fenestration Requirements
Climate Zone 1 2 3 4 5 6 7 8
Vertical Fenestration (0-40% of wall)
Maximum U-factor
Non-metal frame 0.50 0.37 0.33 0.31 0.31 0.30 0.28 0.25
Metal frame, fixed 0.57 0.54 0.45 0.38 0.38 0.36 0.33 0.29
Metal frame, operable 0.65 0.65 0.60 0.46 0.46 0.45 0.40 0.35
Metal frame, entrance door 1.10 0.83 0.77 0.68 0.68 0.68 0.68 0.68
Maximum SHGC
All vertical fenestration 0.25 0.25 0.25 0.36 0.38 0.40 0.45 0.45
Minimum Assembly VT/SHGC
All vertical fenestration 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.10
Skylights (0-3% of roof)
Maximum U-factor
all skylights 0.75 0.65 0.55 0.50 0.50 0.50 0.50 0.41
Maximum SHGC
all skylights 0.35 0.35 0.35 0.40 0.40 0.40 NR NR
Minimum Assembly VT/SHGC
All skylights NR NR NR NR NR NR NR NR

 

There are orientation requirements in section 5.5.4.5 that encourages using lower SHGC on east and west orientations while still allowing the design flexibility to comply using external shading and window distribution.

2016 |2010 | 2007 | 2004

ASHRAE Standard 90.1-2010

ASHRAE Standard 90.1-2010 is still a widely used version of ASHRAE 90.1. Like all versions of the standard, its prescriptive building envelope option sets U-factor and SHGC requirements and fenestration area limits. Other compliance options allow greater design flexibility but are more complex. Regardless of the chosen compliance option, fenestration must not exceed mandatory air leakage limits.

The prescriptive option limits vertical fenestration area to 40% of the gross above-grade wall area. With exceptions for some buildings, the area of west-oriented and east-oriented vertical fenestration must each not exceed the area of south-oriented vertical fenestration.

The prescriptive option limits skylight area to 5% of the gross roof area. In some larger spaces with high ceilings, the code requires a minimum skylight area for daylighting.

ASHRAE 90.1-2010 Prescriptive Fenestration Requirements
Climate Zone 1 2 3 4 5 6 7 8
Vertical Fenestration
Maximum U-factor
Framing materials other than metal with or without metal reinforcement or cladding
Non-metal frame 1.20 0.75 0.65 0.40 0.35 0.350.350.35
Metal framing with or without thermal break
Curtain wall/storefront 1.20 0.70 0.60 0.50 0.45 0.45 0.40 0.40
Entrance door 1.20 1.10 0.90 0.85 0.80 0.800.800.80
All other metal frame 1.20 0.75 0.65 0.55 0.55 0.550.450.45
Maximum SHGC
All vertical fenestration 0.25 0.25 0.25 0.40 0.40 0.400.450.45
Skylights with Glass & Curb
Maximum U-factor
with curb 1.98 1.98 1.17 1.171.171.171.170.98
without curb 1.36 1.36 0.69 0.69 0.69 0.690.690.58
Maximum SHGC
0%-2% of roof area 0.36 0.36 0.39 0.49 0.49 0.490.68Any
2.1%-5% of roof area 0.19 0.19 0.19 0.39 0.39 0.490.64Any

 

SHGC requirements for vertical fenestration are adjusted where shading from permanent projections is provided. For skylights with plastic and curb, different requirements apply.

Mandatory air leakage limits depend on the fenestration type. For windows, sliding doors, swinging doors and most skylights, the maximum air leakage rate is 0.2 cfm/ft2, or 0.3 cfm/ft2 if tested at 6.24 psf.

2016 |2010 | 2007 | 2004

ASHRAE Standard 90.1-2007
ASHRAE Standard 90.1-2007, like all versions of the standard, has a prescriptive building envelope option that sets U-factor and SHGC requirements and fenestration area limits. Other compliance options allow greater design flexibility but are more complex. Regardless of the chosen compliance option, fenestration must not exceed mandatory air leakage limits.

The prescriptive option limits vertical fenestration area to 40% of the gross above-grade wall area and skylight area to 5% of the gross roof area.

ASHRAE 90.1-2007 Prescriptive Fenestration Requirements
Climate Zone 1 2 3 4 5 6 7 8
Vertical Fenestration
Maximum U-factor
Framing materials other than metal with or without metal reinforcement or cladding
Non-metal frame 1.20 0.75 0.65 0.40 0.35 0.350.350.35
Metal framing with or without thermal break
Curtain wall/storefront 1.20 0.70 0.60 0.50 0.45 0.45 0.40 0.40
Entrance door 1.20 1.10 0.90 0.85 0.80 0.800.800.80
All other metal fram 1.20 0.75 0.65 0.55 0.55 0.550.450.45
Maximum SHGC
All vertical fenestration 0.25 0.25 0.25 0.40 0.40 0.400.450.45
Skylights with Glass
Maximum U-factor
with curb 1.98 1.98 1.17 1.171.171.171.170.98
without curb curb 1.36 1.36 0.69 0.69 0.69 0.690.690.58
Maximum SHGC
0%-2% of roof area 0.36 0.36 0.39 0.49 0.49 0.490.68Any
2.1%-5% of roof area 0.19 0.19 0.19 0.39 0.39 0.490.64Any

 

SHGC requirements for vertical fenestration are adjusted where shading from permanent projections is provided. For skylights with plastic and curb, different requirements apply.

Mandatory air leakage limits depend on the fenestration type. For windows, sliding doors and skylights, the maximum air leakage rate is 0.4 cfm/ft2.

2016 |2010 | 2007 | 2004

ASHRAE Standard 90.1-2004
ASHRAE Standard 90.1-2004, like all versions of the standard, has a prescriptive building envelope option that sets U-factor and SHGC requirements and fenestration area limits. Other compliance options allow greater design flexibility but are more complex. Regardless of the chosen compliance option, fenestration must not exceed mandatory air leakage limits.

The prescriptive option limits vertical fenestration area to 50% of the gross above-grade wall area and skylight area to 5% of the gross roof area.

ASHRAE 90.1-2004 Prescriptive Fenestration Requirements
Climate Zone 1 2 3A 3B 4 5 6 7 8
Vertical Fenestration
Maximum U-factor
Fixed vertical fenestration
0-10% of wall area 1.22 1.22 0.57 1.22 0.57 0.57 0.57 0.57 0.46
10.1-40% of wall area 1.22 1.22 0.57 1.22 0.57 0.57 0.57 0.57 0.46
40.1-50% of wall area 1.22 1.22 0.46 1.22 0.46 0.46 0.46 0.46 0.35
Operable vertical fenestration
0-10% of wall area 1.27 1.27 0.67 1.27 0.67 0.67 0.67 0.67 0.47
10.1-40% of wall area 1.27 1.27 0.67 1.27 0.67 0.67 0.67 0.67 0.47
40.1-50% of wall area 1.27 1.27 0.47 1.27 0.47 0.47 0.47 0.47 0.39
Maximum SHGC, all orientations
0-10% of wall area 0.25 0.25 0.39 0.61 0.39 0.49 0.49 0.49 Any
10.1-40% of wall area 0.25 0.25 0.25 0.39 0.39 0.39 0.39 0.49 Any
40.1-50% of wall area 0.19 0.17 0.19 0.20 0.25 0.26 0.26 0.36 Any
Skylights with Glass
Maximum U-factor
with curb 1.98 1.98 1.17 1.98 1.17 1.17 1.17 1.17 0.98
without curb 1.36 1.36 0.69 1.36 0.69 0.69 0.69 0.69 0.58
Maximum SHGC
0%-2% or roof area 0.36 0.36 0.39 0.61 0.49 0.49 0.49 0.68 Any
2.1%-5% of roof area 0.19 0.19 0.19 0.39 0.39 0.39 0.49 0.64 Any

 

SHGC requirements for vertical fenestration are adjusted for north-oriented glazing and where shading from permanent projections is provided. For skylights with plastic and curb, different requirements apply.

Mandatory air leakage limits depend on the fenestration type. For windows, sliding doors and skylights, the maximum air leakage rate is 0.4 cfm/ft2.

2016 |2010 | 2007 | 2004

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