3.5.7 Fenestration

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface.
Units	Text, unique
Input Restrictions	No restrictions
Baseline Rules	Not applicable

Fenestration Type (Vertical Fenestration)
Applicability	All vertical fenestration
Definition	This is a classification of vertical fenestration that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List (ASHRAE Standard 90.1-2007): Nonmetal framing (all); metal framing (curtainwall/storefront); metal framing (entrance door); or metal framing (all other) List (ASHRAE Standard 90.1-2001): Fixed or Operable
Input Restrictions	No restrictions, other than that the vertical fenestration type must agree with the type specified on the construction documents or the as-built drawings.
Baseline Rules	Same as the proposed design

Fenestration Type (Skylights)
Applicability	All skylights
Definition	This is a classification of skylights that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List: Glass skylight with curb; plastic skylight with curb; or skylights with no curb
Input Restrictions	No restrictions, other than the skylight types specified must agree with the construction documents or the as-built drawings.
Baseline Rules	Same as the proposed design

Fenestration Geometry
Applicability	All fenestration
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.
Baseline Rules	The geometry of the fenestration shall be identical to the proposed design with the following exceptions: If the gross area of all windows in the building exceeds 40% of the gross above-grade exterior wall area in the building, the dimensions of each window in the baseline building shall be reduced in size such that the window area in the baseline building is equal to 40% of the above-grade exterior wall area. If the gross area of skylights in the building exceeds 5% of the gross roof area, the dimensions of each skylight shall be reduced in size such that the skylight area in the proposed design is equal to 5% of the gross roof area.

Fenestration Construction
Applicability	All fenestration
Definition	A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, SHGC and VT . Data may be specified in other ways, however, as long as the data are supported by appropriate tests.
Units	Data structure: fenestration construction
Input Restrictions	Performance information for fenestration shall be developed from NFRC test procedures or shall be taken from the default values in Appendix A of the baseline standard. Values entered shall be consistent with the specifications and the construction documents.
Baseline Rules	The requirements for vertical fenestration U factor, Solar Heat Gain Coefficient, and Visible light transmission by climate zone and framing type are found in [bookref id="baseline-building-criteria-for-vertical-glazing-for-90.1-2001"] and for skylight inputs in [bookref id="Baseline Building Criteria for Skylights" id="baseline-building-criteria-for-skylights"]. In cases where there is no requirement (NR) for SHGC or VT, the baseline building shall be equal to the proposed design.

[table title="Baseline Building Criteria for Vertical Glazing for 90.1 2001" id="baseline-building-criteria-for-vertical-glazing-for-90.1-2001"]

Building type	Climate Zone	Window to Wall Ratio	Standard Design
			Assembly U-factor		Assembly SHGC		Assembly VT
			Fixed	Operable	All	North	All	North
Nonresidential	1	0-30.0%	1.22	1.27	0.25	0.61	0.25	0.61
	1	30.1-40.0%	1.22	1.27	0.25	0.44	0.25	0.44
	2	0-40.0%	1.22	1.27	0.25	0.61	0.25	0.61
	3(A,B)	0-10.0%	0.57	0.67	0.39	0.49	0.39	0.49
		10.1-20.0%	0.57	0.67	0.25	0.49	0.25	0.49
		20.1-40.0%	0.57	0.67	0.25	0.39	0.25	0.39
	3(C)	0-10.0%	1.22	1.27	0.61	0.82	0.61	0.82
	3(C)	10.1-40.0%	1.22	1.27	0.39	0.61	0.39	0.61
	4	0-40.0%	0.57	0.67	0.39	0.49	0.50	0.62
	5	0-10.0%	0.57	0.67	0.49	0.49	0.62	0.62
	5	10.1-40.0%	0.57	0.67	0.39	0.49	0.50	0.62
	6	0-10.0%	0.57	0.67	0.49	0.49	0.62	0.62
	6	10.1-40.0%	0.57	0.67	0.39	0.49	0.50	0.62
	7	0-40.0%	0.57	0.67	0.49	0.64	0.49	0.64
	8	0-40.0%	0.46	0.47	NR	NR	NR	NR
Residential	1	0-30.0%	1.22	1.27	0.25	0.61	0.25	0.61
	1	30.1-40.0%	1.22	1.27	0.25	0.44	0.25	0.44
	2	0-10.0%	1.22	1.27	0.39	0.61	0.39	0.61
	2	10.1-40.0%	1.22	1.27	0.25	0.61	0.25	0.61
	3(A,B)	0-10.0%	0.57	0.67	0.39	0.49	0.39	0.49
		10.1-20.0%	0.57	0.67	0.25	0.49	0.25	0.49
		20.1-40.0%	0.57	0.67	0.25	0.39	0.25	0.39
	3(C)	0-10.0%	1.22	1.27	0.61	0.82	0.61	0.82
		10.1-20.0%	1.22	1.27	0.61	0.61	0.61	0.61
		20.1-30.0%	1.22	1.27	0.39	0.61	0.39	0.61
		30.1-40.0%	1.22	1.27	0.34	0.61	0.34	0.61
	4	0-40.0%	0.57	0.67	0.39	0.49	0.50	0.62
	5	0-10.0%	0.57	0.67	0.49	0.49	0.62	0.62
	5	10.1-40.0%	0.57	0.67	0.39	0.39	0.50	0.50
	6	0-10.0%	0.57	0.67	0.49	0.64	0.62	0.81
	6	10.1-40.0%	0.57	0.67	0.39	0.49	0.50	0.62
	7	0-40.0%	0.57	0.67	0.49	0.64	0.62	0.81
	8	0-40.0%	0.46	0.47	NR	NR	NR	NR
Semiheated	1-8	0-40.0%	1.22	1.27	NR	NR	NR	NR

[table title="Baseline Building Criteria for Vertical Glazing for 90.1 2007 and 90.1-2010" id="baseline-building-criteria-for-vertical-glazing-for- 90.1-2007"]

Building type	Fenestration Type	Climate Zone	Standard Design
Building type	Fenestration Type	Climate Zone	U-factor	SHGC	VT
Nonresidential	Non-Metal Framing	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.40	0.40	0.51
		5,6	0.35	0.40	0.51
		7,8	0.35	0.45	0.57
	Metal Framing Curtainwall/ Storefront	1	1.20	0.25	0.32
		2	0.70	0.25	0.32
		3	0.60	0.25	0.32
		4	0.50	0.40	0.51
		5,6	0.45	0.40	0.51
		7,8	0.40	0.45	0.57
	Metal Framing Entrance Door	1	1.20	0.25	0.32
		2	1.10	0.25	0.32
		3	0.90	0.25	0.32
		4	0.85	0.40	0.51
		5,6	0.80	0.40	0.51
		7,8	0.80	0.45	0.57
Nonresidential (Continued)	Metal Framing All Other	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.55	0.40	0.51
		5,6	0.55	0.40	0.51
		7,8	0.45	0.45	0.57
Residential	Non-Metal Framing	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.40	0.40	0.51
		5,6	0.35	0.40	0.51
		7,8	0.35	NR	NR
	Metal Framing Curtainwall/ Storefront	1	1.20	0.25	0.32
		2	0.70	0.25	0.32
		3	0.60	0.25	0.32
		4	0.50	0.40	0.51
		5,6	0.45	0.40	0.51
		7,8	0.40	NR	NR
	Metal Framing Entrance Door	1	1.20	0.25	0.32
		2	1.10	0.25	0.32
		3	0.90	0.25	0.32
		4	0.85	0.40	0.51
		5,6	0.80	0.40	0.51
		7,8	0.80	NR	NR
	Metal Framing All Other	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.55	0.40	0.51
		5,6	0.55	0.40	0.51
		7,8	0.45	NR	NR
Residential	Non-Metal Framing	1- 5	1.20	NR	NR
	Non-Metal Framing	6- 8	0.65	NR	NR
	Metal Framing Curtainwall/ Storefront	1- 5	1.20	NR	NR
	Metal Framing Curtainwall/ Storefront	6- 8	0.60	NR	NR
	Metal Framing Entrance Door	1- 5	1.20	NR	NR
	Metal Framing Entrance Door	6- 8	0.90	NR	NR
Residential (Continued)	Metal Framing All Other	1- 5	1.20	NR	NR
Residential (Continued)	Metal Framing All Other	6- 8	0.65	NR	NR

[table title="Baseline Building Criteria for Skylights" id="baseline-building-criteria-for-skylights"]

Proposed Design	Applicable Standard	Climate Zone	% of Roof	Standard Design
Proposed Design	Applicable Standard	Climate Zone	% of Roof	U-factor	SHGC	VT
Glass Skylight with Curb	90.1 – 2001 & 90.1 - 2007	1,2	0-2.0%	1.98	0.36	0.46
		1,2	2.1-5.0%	1.98	0.19	0.24
		3 (A,B) - (all climate zone 3 for 2007)	0-2.0%	1.17	0.39	0.50
		3 (A,B) - (all climate zone 3 for 2007)	2.1-5.0%	1.17	0.19	0.24
		3 (C) (2001 only)	0-2.0%	1.98	0.61	0.77
		3 (C) (2001 only)	2.1-5.0%	1.98	0.39	0.50
		4,5	0-2.0%	1.17	0.49	0.62
		4,5	2.1-5.0%	1.17	0.39	0.50
		6	0-5.0%	1.17	0.49	0.62
		7	0-2.0%	1.17	0.68	0.68
		7	2.1-5.0%	1.17	0.64	0.64
		8	0-2.0%	0.98	0.55	0.63
Plastic Skylight with Curb	90.1 - 2001 & 90.1 - 2007	1	0-2.0%	1.90	0.34	0.41
		1	2.1-5.0%	1.90	0.27	0.32
		2	0-2.0%	1.90	0.39	0.47
		2	2.1-5.0%	1.90	0.34	0.41
		3,4	0-2.0%	1.30	0.65	0.78
		3,4	2.1-5.0%	1.30	0.34	0.41
		5	0-2.0%	1.10	0.77	0.92
		5	2.1-5.0%	1.10	0.62	0.74
		6	0-2.0%	0.87	0.71	0.85
		6	2.1-5.0%	0.87	0.58	0.70
		7	0-2.0%	0.87	0.77	0.92
		7	2.1-5.0%	0.87	0.71	0.85
		8	0-2.0%	0.61	0.59	0.64
Skylight without Curb	90.1 – 2001 & 90.1 – 2007	1,2	0-2.0%	1.36	0.36	0.46
		1,2	2.1-5.0%	1.36	0.19	0.24
		3 (A,B) - (all climate zone 3 for 2007)	0-2.0%	0.69	0.39	0.50
		3 (A,B) - (all climate zone 3 for 2007)	2.1-5.0%	0.69	0.19	0.24
		3 (C) (2001 only)	0-2.0%	1.36	0.61	0.77
		3 (C) (2001 only)	2.1-5.0%	1.36	0.39	0.50
		4,5	0-2.0%	0.69	0.49	0.62
		4,5	2.1-5.0%	0.69	0.39	0.50
		6	0-5.0%	0.69	0.49	0.62
		7	0-2.0%	0.69	0.68	0.68
		7	2.1-5.0%	0.69	0.64	0.64
		8	0-5.0%	0.58	0.55	0.63

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall, that are documented on the construction documents and shade the glazing. Objects that shade the building but that are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. See Shading of the Building Site.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than that the inputs must match the construction documents
Baseline Rules	The baseline building is modeled without external shading devices.

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings or components or treatments of the glazing materials are addressed through the Fenestration Construction building descriptor.
Units	Data structure
Input Restrictions	Internal shading shall not be modeled in the proposed design, unless it is automatically controlled, based on input from an astronomical timeclock, an exterior pyronometer, or other sensors. The control algorithm shall be documented on the construction documents. Interior shades without automatic controls shall not be modeled.
Baseline Rules	The baseline building shall be modeled without interior shades.

90.1-2007

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface.
Units	Text, unique
Input Restrictions	No restrictions
Baseline Rules	Not applicable

Fenestration Type (Vertical Fenestration)
Applicability	All vertical fenestration
Definition	This is a classification of vertical fenestration that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List (ASHRAE Standard 90.1-2007): Nonmetal framing (all); metal framing (curtainwall/storefront); metal framing (entrance door); or metal framing (all other)
Input Restrictions	No restrictions, other than that the vertical fenestration type must agree with the type specified on the construction documents or the as-built drawings.
Baseline Rules	Same as the proposed design

Fenestration Type (Skylights)
Applicability	All skylights
Definition	This is a classification of skylights that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List: Glass skylight with curb; plastic skylight with curb; or skylights with no curb
Input Restrictions	No restrictions, other than the skylight types specified must agree with the construction documents or the as-built drawings.
Baseline Rules	Same as the proposed design

Fenestration Geometry
Applicability	All fenestration
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.
Baseline Rules	The geometry of the fenestration shall be identical to the proposed design with the following exceptions: If the gross area of all windows in the building exceeds 40% of the gross above-grade exterior wall area in the building, the dimensions of each window in the baseline building shall be reduced in size such that the window area in the baseline building is equal to 40% of the above-grade exterior wall area. If the gross area of skylights in the building exceeds 5% of the gross roof area, the dimensions of each skylight shall be reduced in size such that the skylight area in the proposed design is equal to 5% of the gross roof area.

Fenestration Construction
Applicability	All fenestration
Definition	A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, SHGC and VT . Data may be specified in other ways, however, as long as the data are supported by appropriate tests.
Units	Data structure: fenestration construction
Input Restrictions	Performance information for fenestration shall be developed from NFRC test procedures or shall be taken from the default values in Appendix A of the baseline standard. Values entered shall be consistent with the specifications and the construction documents.
Baseline Rules	The requirements for vertical fenestration U factor, Solar Heat Gain Coefficient, and Visible light transmission by climate zone and framing type are found in [bookref id="baseline-building-criteria-for-vertical-glazing-for- 90.1-2007"] and for skylight inputs in [bookref id="Baseline Building Criteria for Skylights" id="baseline-building-criteria-for-skylights"]. In cases where there is no requirement (NR) for SHGC or VT, the baseline building shall be equal to the proposed design.

[table title="Baseline Building Criteria for Vertical Glazing for 90.1 2007 and 90.1-2010" id="baseline-building-criteria-for-vertical-glazing-for- 90.1-2007"]

Building type	Fenestration Type	Climate Zone	Standard Design
Building type	Fenestration Type	Climate Zone	U-factor	SHGC	VT
Nonresidential	Non-Metal Framing	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.40	0.40	0.51
		5,6	0.35	0.40	0.51
		7,8	0.35	0.45	0.57
	Metal Framing Curtainwall/ Storefront	1	1.20	0.25	0.32
		2	0.70	0.25	0.32
		3	0.60	0.25	0.32
		4	0.50	0.40	0.51
		5,6	0.45	0.40	0.51
		7,8	0.40	0.45	0.57
	Metal Framing Entrance Door	1	1.20	0.25	0.32
		2	1.10	0.25	0.32
		3	0.90	0.25	0.32
		4	0.85	0.40	0.51
		5,6	0.80	0.40	0.51
		7,8	0.80	0.45	0.57
Nonresidential (Continued)	Metal Framing All Other	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.55	0.40	0.51
		5,6	0.55	0.40	0.51
		7,8	0.45	0.45	0.57
Residential	Non-Metal Framing	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.40	0.40	0.51
		5,6	0.35	0.40	0.51
		7,8	0.35	NR	NR
	Metal Framing Curtainwall/ Storefront	1	1.20	0.25	0.32
		2	0.70	0.25	0.32
		3	0.60	0.25	0.32
		4	0.50	0.40	0.51
		5,6	0.45	0.40	0.51
		7,8	0.40	NR	NR
	Metal Framing Entrance Door	1	1.20	0.25	0.32
		2	1.10	0.25	0.32
		3	0.90	0.25	0.32
		4	0.85	0.40	0.51
		5,6	0.80	0.40	0.51
		7,8	0.80	NR	NR
	Metal Framing All Other	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.55	0.40	0.51
		5,6	0.55	0.40	0.51
		7,8	0.45	NR	NR
Residential	Non-Metal Framing	1- 5	1.20	NR	NR
	Non-Metal Framing	6- 8	0.65	NR	NR
	Metal Framing Curtainwall/ Storefront	1- 5	1.20	NR	NR
	Metal Framing Curtainwall/ Storefront	6- 8	0.60	NR	NR
	Metal Framing Entrance Door	1- 5	1.20	NR	NR
	Metal Framing Entrance Door	6- 8	0.90	NR	NR
Residential (Continued)	Metal Framing All Other	1- 5	1.20	NR	NR
Residential (Continued)	Metal Framing All Other	6- 8	0.65	NR	NR

Applicable to all window to wall ratios (0-40.0%)

[table title="Baseline Building Criteria for Skylights" id="baseline-building-criteria-for-skylights"]

Proposed Design	Applicable Standard	Climate Zone	% of Roof	Standard Design
Proposed Design	Applicable Standard	Climate Zone	% of Roof	U-factor	SHGC	VT
Glass Skylight with Curb	90.1 – 2001 & 90.1 - 2007	1,2	0-2.0%	1.98	0.36	0.46
		1,2	2.1-5.0%	1.98	0.19	0.24
		3 (A,B) - (all climate zone 3 for 2007)	0-2.0%	1.17	0.39	0.50
		3 (A,B) - (all climate zone 3 for 2007)	2.1-5.0%	1.17	0.19	0.24
		3 (C) (2001 only)	0-2.0%	1.98	0.61	0.77
		3 (C) (2001 only)	2.1-5.0%	1.98	0.39	0.50
		4,5	0-2.0%	1.17	0.49	0.62
		4,5	2.1-5.0%	1.17	0.39	0.50
		6	0-5.0%	1.17	0.49	0.62
		7	0-2.0%	1.17	0.68	0.68
		7	2.1-5.0%	1.17	0.64	0.64
		8	0-2.0%	0.98	0.55	0.63
Plastic Skylight with Curb	90.1 - 2001 & 90.1 - 2007	1	0-2.0%	1.90	0.34	0.41
		1	2.1-5.0%	1.90	0.27	0.32
		2	0-2.0%	1.90	0.39	0.47
		2	2.1-5.0%	1.90	0.34	0.41
		3,4	0-2.0%	1.30	0.65	0.78
		3,4	2.1-5.0%	1.30	0.34	0.41
		5	0-2.0%	1.10	0.77	0.92
		5	2.1-5.0%	1.10	0.62	0.74
		6	0-2.0%	0.87	0.71	0.85
		6	2.1-5.0%	0.87	0.58	0.70
		7	0-2.0%	0.87	0.77	0.92
		7	2.1-5.0%	0.87	0.71	0.85
		8	0-2.0%	0.61	0.59	0.64
Skylight without Curb	90.1 – 2001 & 90.1 – 2007	1,2	0-2.0%	1.36	0.36	0.46
		1,2	2.1-5.0%	1.36	0.19	0.24
		3 (A,B) - (all climate zone 3 for 2007)	0-2.0%	0.69	0.39	0.50
		3 (A,B) - (all climate zone 3 for 2007)	2.1-5.0%	0.69	0.19	0.24
		3 (C) (2001 only)	0-2.0%	1.36	0.61	0.77
		3 (C) (2001 only)	2.1-5.0%	1.36	0.39	0.50
		4,5	0-2.0%	0.69	0.49	0.62
		4,5	2.1-5.0%	0.69	0.39	0.50
		6	0-5.0%	0.69	0.49	0.62
		7	0-2.0%	0.69	0.68	0.68
		7	2.1-5.0%	0.69	0.64	0.64
		8	0-5.0%	0.58	0.55	0.63

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall, that are documented on the construction documents and shade the glazing. Objects that shade the building but that are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. See Shading of the Building Site.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than that the inputs must match the construction documents
Baseline Rules	The baseline building is modeled without external shading devices.

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings or components or treatments of the glazing materials are addressed through the Fenestration Construction building descriptor.
Units	Data structure
Input Restrictions	Internal shading shall not be modeled in the proposed design, unless it is automatically controlled, based on input from an astronomical timeclock, an exterior pyronometer, or other sensors. The control algorithm shall be documented on the construction documents. Interior shades without automatic controls shall not be modeled.
Baseline Rules	The baseline building shall be modeled without interior shades.

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface.
Units	Text, unique
Input Restrictions	No restrictions
Baseline Rules	Not applicable

Fenestration Type (Vertical Fenestration)
Applicability	All vertical fenestration
Definition	This is a classification of vertical fenestration that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List (ASHRAE Standard 90.1-2007): Nonmetal framing (all); metal framing (curtainwall/storefront); metal framing (entrance door); or metal framing (all other)
Input Restrictions	No restrictions, other than that the vertical fenestration type must agree with the type specified on the construction documents or the as-built drawings.
Baseline Rules	Same as the proposed design

Fenestration Type (Skylights)
Applicability	All skylights
Definition	This is a classification of skylights that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List: Glass skylight with curb; plastic skylight with curb; or skylights with no curb
Input Restrictions	No restrictions, other than the skylight types specified must agree with the construction documents or the as-built drawings.
Baseline Rules	Same as the proposed design

Fenestration Geometry
Applicability	All fenestration
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.
Baseline Rules	The geometry of the fenestration shall be identical to the proposed design with the following exceptions: If the gross area of all windows in the building exceeds 40% of the gross above-grade exterior wall area in the building, the dimensions of each window in the baseline building shall be reduced in size such that the window area in the baseline building is equal to 40% of the above-grade exterior wall area. If the gross area of skylights in the building exceeds 5% of the gross roof area, the dimensions of each skylight shall be reduced in size such that the skylight area in the proposed design is equal to 5% of the gross roof area.

Fenestration Construction
Applicability	All fenestration
Definition	A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, SHGC and VT . Data may be specified in other ways, however, as long as the data are supported by appropriate tests.
Units	Data structure: fenestration construction
Input Restrictions	Performance information for fenestration shall be developed from NFRC test procedures or shall be taken from the default values in Appendix A of the baseline standard. Values entered shall be consistent with the specifications and the construction documents.
Baseline Rules	The requirements for vertical fenestration U factor, Solar Heat Gain Coefficient, and Visible light transmission by climate zone and framing type are found in Table 6.5.7-1 and for skylight inputs in Table 6.5.7-2. In cases where there is no requirement (NR) for SHGC or VT, the baseline building shall be equal to the proposed design.

Table 6.5.7-1: Baseline Building Criteria for Vertical Glazing for 90.1 2007 and 90.1-2010

Building type	Fenestration Type	Climate Zone	Standard Design
Building type	Fenestration Type	Climate Zone	U-factor	SHGC	VT
Nonresidential	Non-Metal Framing	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.40	0.40	0.51
		5,6	0.35	0.40	0.51
		7,8	0.35	0.45	0.57
	Metal Framing Curtainwall/ Storefront	1	1.20	0.25	0.32
		2	0.70	0.25	0.32
		3	0.60	0.25	0.32
		4	0.50	0.40	0.51
		5,6	0.45	0.40	0.51
		7,8	0.40	0.45	0.57
	Metal Framing Entrance Door	1	1.20	0.25	0.32
		2	1.10	0.25	0.32
		3	0.90	0.25	0.32
		4	0.85	0.40	0.51
		5,6	0.80	0.40	0.51
		7,8	0.80	0.45	0.57
Nonresidential (Continued)	Metal Framing All Other	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.55	0.40	0.51
		5,6	0.55	0.40	0.51
		7,8	0.45	0.45	0.57
Residential	Non-Metal Framing	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.40	0.40	0.51
		5,6	0.35	0.40	0.51
		7,8	0.35	NR	NR
	Metal Framing Curtainwall/ Storefront	1	1.20	0.25	0.32
		2	0.70	0.25	0.32
		3	0.60	0.25	0.32
		4	0.50	0.40	0.51
		5,6	0.45	0.40	0.51
		7,8	0.40	NR	NR
	Metal Framing Entrance Door	1	1.20	0.25	0.32
		2	1.10	0.25	0.32
		3	0.90	0.25	0.32
		4	0.85	0.40	0.51
		5,6	0.80	0.40	0.51
		7,8	0.80	NR	NR
	Metal Framing All Other	1	1.20	0.25	0.32
		2	0.75	0.25	0.32
		3	0.65	0.25	0.32
		4	0.55	0.40	0.51
		5,6	0.55	0.40	0.51
		7,8	0.45	NR	NR
Residential	Non-Metal Framing	1- 5	1.20	NR	NR
	Non-Metal Framing	6- 8	0.65	NR	NR
	Metal Framing Curtainwall/ Storefront	1- 5	1.20	NR	NR
	Metal Framing Curtainwall/ Storefront	6- 8	0.60	NR	NR
	Metal Framing Entrance Door	1- 5	1.20	NR	NR
	Metal Framing Entrance Door	6- 8	0.90	NR	NR
Residential (Continued)	Metal Framing All Other	1- 5	1.20	NR	NR
Residential (Continued)	Metal Framing All Other	6- 8	0.65	NR	NR

Applicable to all window to wall ratios (0-40.0%)

Table 6.5.7-2: Baseline Building Criteria for Skylights

Proposed Design	Applicable Standard	Climate Zone	% of Roof	Standard Design
Proposed Design	Applicable Standard	Climate Zone	% of Roof	U-factor	SHGC	VT
Glass Skylight with Curb	90.1 – 2001 & 90.1 - 2007	1,2	0-2.0%	1.98	0.36	0.46
		1,2	2.1-5.0%	1.98	0.19	0.24
		3 (A,B) - (all climate zone 3 for 2007)	0-2.0%	1.17	0.39	0.50
		3 (A,B) - (all climate zone 3 for 2007)	2.1-5.0%	1.17	0.19	0.24
		3 (C) (2001 only)	0-2.0%	1.98	0.61	0.77
		3 (C) (2001 only)	2.1-5.0%	1.98	0.39	0.50
		4,5	0-2.0%	1.17	0.49	0.62
		4,5	2.1-5.0%	1.17	0.39	0.50
		6	0-5.0%	1.17	0.49	0.62
		7	0-2.0%	1.17	0.68	0.68
		7	2.1-5.0%	1.17	0.64	0.64
		8	0-2.0%	0.98	0.55	0.63
Plastic Skylight with Curb	90.1 - 2001 & 90.1 - 2007	1	0-2.0%	1.90	0.34	0.41
		1	2.1-5.0%	1.90	0.27	0.32
		2	0-2.0%	1.90	0.39	0.47
		2	2.1-5.0%	1.90	0.34	0.41
		3,4	0-2.0%	1.30	0.65	0.78
		3,4	2.1-5.0%	1.30	0.34	0.41
		5	0-2.0%	1.10	0.77	0.92
		5	2.1-5.0%	1.10	0.62	0.74
		6	0-2.0%	0.87	0.71	0.85
		6	2.1-5.0%	0.87	0.58	0.70
		7	0-2.0%	0.87	0.77	0.92
		7	2.1-5.0%	0.87	0.71	0.85
		8	0-2.0%	0.61	0.59	0.64
Skylight without Curb	90.1 – 2001 & 90.1 – 2007	1,2	0-2.0%	1.36	0.36	0.46
		1,2	2.1-5.0%	1.36	0.19	0.24
		3 (A,B) - (all climate zone 3 for 2007)	0-2.0%	0.69	0.39	0.50
		3 (A,B) - (all climate zone 3 for 2007)	2.1-5.0%	0.69	0.19	0.24
		3 (C) (2001 only)	0-2.0%	1.36	0.61	0.77
		3 (C) (2001 only)	2.1-5.0%	1.36	0.39	0.50
		4,5	0-2.0%	0.69	0.49	0.62
		4,5	2.1-5.0%	0.69	0.39	0.50
		6	0-5.0%	0.69	0.49	0.62
		7	0-2.0%	0.69	0.68	0.68
		7	2.1-5.0%	0.69	0.64	0.64
		8	0-5.0%	0.58	0.55	0.63

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall, that are documented on the construction documents and shade the glazing. Objects that shade the building but that are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. See Shading of the Building Site.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than that the inputs must match the construction documents
Baseline Rules	The baseline building is modeled without external shading devices.

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings or components or treatments of the glazing materials are addressed through the Fenestration Construction building descriptor.
Units	Data structure
Input Restrictions	Internal shading shall not be modeled in the proposed design, unless it is automatically controlled, based on input from an astronomical timeclock, an exterior pyronometer, or other sensors. The control algorithm shall be documented on the construction documents. Interior shades without automatic controls shall not be modeled.
Baseline Rules	The baseline building shall be modeled without interior shades.

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface.
Units	Text, unique
Input Restrictions	No restrictions
Baseline Rules	Not applicable

Fenestration Type (Vertical Fenestration)
Applicability	All vertical fenestration, optional input
Definition	This is a classification of vertical fenestration that determines the prescriptive thermal performance and solar performance requirement for vertical fenestration. It is not used for performance calculations.
Units	List (ASHRAE Standard 90.1-2013): Nonmetal framing (all); metal framing (curtainwall/storefront); metal framing (entrance door); or metal framing (all other)
Input Restrictions	No restrictions, other than that the vertical fenestration type must agree with the type specified on the construction documents or the as-built drawings.
Baseline Rules	The performance of the baseline building fenestration is specified independent of this input.

Fenestration Type (Skylights)
Applicability	All skylights, optional input
Definition	This is a classification of skylights that determines the prescriptive thermal performance and solar performance requirement for skylights. It is not used for performance calculations.
Units	List: Glass skylight with curb; plastic skylight with curb; or skylights with no curb
Input Restrictions	No restrictions, other than the skylight types specified must agree with the construction documents or the as-built drawings.
Baseline Rules	Skylights in the baseline building are specified independent of this input. All skylights in the baseline building are assumed to be “skylights with no curb”.

Vertical Fenestration Geometry
Applicability	All vertical fenestration
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.
Baseline Rules	The geometry of the vertical fenestration shall be similar to the proposed design but each fenestration shall be increased or reduced in size in proportion to the proposed design size such that the overall fenestration area as a percentage of the above-grade exterior wall area is equal to the values in Table 3.5.7x.

Table 3.5.7-1: Baseline Building Vertical Fenestration Area

Building Area Typesa	Baseline Building Gross Above-Grade-Wall Area
Grocery Store	7%
Healthcare (outpatient)	21%
Hospital	27%
Hotel/motel (≤75 rooms)	24%
Hotel/motel (>75 rooms)	34%
Office (≤5000 ft2)	19%
Office (5000 to 50,000 ft2)	31%
Office (>50,000 ft2)	40%
Restaurant (quick service)	34%
Restaurant (full service)	24%
Retail (stand alone)	11%
Retail (strip mall)	20%
School (primary)	22%
School (secondary and university)	22%
Warehouse (nonrefrigerated)	6%
a. In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply.

Horizontal Fenestration (Skylight) Geometry
Applicability	All horizontal fenestration (skylights)
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.
Baseline Rules	The geometry of the vertical fenestration shall be equal to the proposed design unless the gross area of skylights in the building exceeds 5% of the gross roof area. When this case exists, the dimensions of each skylight shall be reduced in size such that the skylight area in the proposed design is equal to 5% of the gross roof area.

Fenestration Construction
Applicability	All fenestration
Definition	A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, SHGC and VT . Data may be specified in other ways, however, as long as the data are supported by appropriate tests.
Units	Data structure: fenestration construction
Input Restrictions	Performance information for fenestration shall be developed from NFRC test procedures or shall be taken from the default values in Appendix A of the baseline standard. Values entered shall be consistent with the specifications and the construction documents. Dynamic glazing shall be modeled in the proposed design. If the dynamic is controlled automatically, the modeled value of SHGC and VT shall be the average of the minimum and maximum values.
Baseline Rules	The requirements for vertical fenestration U factor, Solar Heat Gain Coefficient, and Visible light transmission by climate zone are found in Table 3.5.7-1 and for skylight inputs in Table 3.5.7-2. In cases where there is no requirement (NR) for SHGC or VT, the baseline building shall be modeled with an SHGC of 0.40 for all vertical fenestration and 0.55 for skylights. VT is not relevant for the baseline building since daylighting is not modeled.

Table 3.5.7-2: U-factor Criteria for Vertical and Horizontal Fenestration

Climate Zone	Nonresidential		Residential		Semi-Heated
	Vertical	Horizontal	Vertical	Horizontal	Vertical	Horizontal
1	1.22	1.36	1.22	1.36	1.22	1.36
2
3	0.57	0.69	0.57	0.69
4
5
6				0.58
7				0.69
8	0.46	0.58	0.46	0.58		0.81

Table 3.5.7-3: SHGC Criteria for Vertical Fenestration

Climate Zone	Nonresidential				Residential				Semi-Heated
	0-10%	10.1-20%	20.1-30%	30.1-40%	0-10%	10.1-20%	20.1-30%	30.1-40%	0-10%
1	0.25	0.25	0.25	0.25	0.25	0.25	0.25	0.25	NR
2					0.39				NR
3	0.39					0.39			NR
4		0.39	0.39	0.39			0.39	0.39	NR
5	0.49				0.49				NR
6									NR
7		0.49	0.49	0.49		0.49	0.49	0.49	NR
8	NR	NR	NR	NR	NR	NR	NR	NR	NR

Table 3.5.7-4: SHGC Criteria for Horizontal Fenestration

Climate Zone	Nonresidential		Residential		Semi-Heated
	0-2%	2.1-5%	0-2%	2.1-5%	0-2%	2.1-5%
1	0.36	0.19	0.19	0.19	NR	NR
2
3	0.39		0.36
4	0.49	0.39
5			0.49	0.49
6		0.49
7	0.68	0.64	0.64	0.64
8	NR	NR	NR	NR

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall, that are documented on the construction documents and shade the glazing. Objects that shade the building but that are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. See Shading of the Building Site.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than that the inputs must match the construction documents
Baseline Rules	The baseline building is modeled without external shading devices.

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings or components or treatments of the glazing materials are addressed through the Fenestration Construction building descriptor.
Units	Data structure
Input Restrictions	Manually operated interior shading devices may or may not be modeled in the proposed design, at the discretion of the energy modeler. Shading devices that are automatically controlled, based on input from an astronomical timeclock, an exterior pyronometer, or other sensors, shall be modeled. The control algorithm shall be documented on the construction documents.
Baseline Rules	If manually operated interior shading devices are modeled in the proposed design, they shall be modeled in a similar manner in the baseline building. The baseline building shall be modeled without interior shades.

3.5.7 Doors

Door Name
Applicability	All exterior doors, optional input
Definition	A unique name or code that relates the door to the design documents submitted. Doors that are more than 50% glass are treated as windows and must be determined and entered by using the fenestration building descriptors.
Units	Text: unique
Input Restrictions	None
Baseline Building	None

Door Type
Applicability	All exterior doors, required input
Definition	For the purposes of determining building envelope requirements, the classifications are defined as follows: Non-swinging: roll-up, metal coiling, sliding, and all other doors that are not swinging doors. Swinging: all operable opaque panels with hinges on one side and opaque revolving doors. The prescriptive U-factor requirements depend on door type and climate. This building descriptor may be derived from other building descriptors, in which case a specific input is not necessary.
Units	List: Swinging or Non-swinging
Input Restrictions	The door type shall be consistent with the type of door represented on the construction documents or as-built drawings
Baseline Building	The baseline building door type shall be the same as the proposed design

Door Geometry
Applicability	All exterior doors
Definition	Door geometry defines the position and dimensions of the door surface relative to its parent wall surface. The azimuth and tilt (if any) of the door are inherited from the parent surface. The position of the door within the parent surface is specified through X,Y coordinates. The size is specified as a height and width (all doors are generally assumed to be rectangular). The details of how the geometry of doors is specified may vary for each energy simulation program.
Units	Data structure: opening
Input Restrictions	As designed
Baseline Building	Door geometry in the baseline building is identical to the proposed design

Door U-factor
Applicability	All exterior doors
Definition	The thermal transmittance of the door, including the frame
Units	Btu/h·ft²·°F
Input Restrictions	Door U-factors shall be taken from the default values in Appendix A of Standard 90.1-2019 or shall be obtained from National Fenestration Rating Council (NFRC) test procedures
Baseline Building	For new construction, the U-factor required for door construction is defined in Table 27

Table 27. Standard 90.1-2019 Requirements for Doors for Baseline Building

Swinging or Non-swinging	Climate Zone	Space Conditioning Category
Swinging or Non-swinging	Climate Zone	Nonresidential U-Value	Residential U-Value	Semi-Heated U-Value
Swinging	Climate Zone 0 and 1	0.7	0.7	0.7
	Climate Zone 2	0.7	0.7	0.7
	Climate Zone 3	0.7	0.7	0.7
	Climate Zone 4	0.7	0.7	0.7
	Climate Zone 5	0.7	0.7	0.7
	Climate Zone 6	0.7	0.5	0.7
	Climate Zone 7	0.7	0.5	0.7
	Climate Zone 8	0.5	0.5	0.7
Non-swinging	Climate Zone 0 and 1	1.45	1.45	1.45
	Climate Zone 2	1.45	1.45	1.45
	Climate Zone 3	1.45	0.5	1.45
	Climate Zone 4	1.45	0.5	1.45
	Climate Zone 5	1.45	0.5	1.45
	Climate Zone 6	0.5	0.5	1.45
	Climate Zone 7	0.5	0.5	1.45
	Climate Zone 8	0.5	0.5	1.45

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is a fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface
Units	Text: unique
Input Restrictions	Not restrictions
Baseline Building	Not applicable

Vertical Fenestration Geometry and Area

Applicability

All fenestration

Definition

Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt are inherited from the parent surface. The details of how the coordinate system is implemented may vary between software programs.

Units

Data structure: opening

Input Restrictions

As designed. The defined fenestration should match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions:

Exterior shading is modeled from buildings, vegetation, and other objects. All elements whose effective height is greater than their distance from a proposed building and whose width facing the proposed building is greater than one-third that of the proposed building shall be accounted for in the analysis.
If daylighting is modeled within the adjacent space.

Baseline Building

The geometry of the vertical fenestration shall be similar to the proposed design but each fenestration shall be increased or reduced in size in proportion to the proposed design size such that the overall fenestration area as a percentage of the above-grade exterior wall area is equal to the values in Table 31. For building areas not shown in Table 31, vertical fenestration areas shall equal that in the proposed design or 40% of gross above-grade wall area, whichever is smaller, and shall be distributed on each face of the building in the same proportions in the proposed design.

If the gross area of all windows (including framing) in each space conditioning category in the building exceeds the value specified in Table 31 of the gross above-grade exterior wall area for that building area type, the dimensions of each window shall be reduced such that the window to wall ration is equal to the value specified in Table 31. This reduction needs to be done by increasing the sill height until the limit is reached for each building area type.

If the WWR of the proposed building design is less than the value specified in Table 31, the dimensions of each window shall be increased equally from the center of the window until a wall or partition is reached. If window area needs to be increased further, then the sill height will be reduced will the maximum WWR limit is reached. If reaching the maximum WWR limit in Table 31 would cause the combined vertical fenestration and opaque door area on a given face to exceed the gross above-grade wall area on that face, then the vertical fenestration area on other faces shall be increased in proportion to the gross above-grade wall area of these faces such that the total baseline building vertical fenestration area is equal to that calculated to achieve the WWR in Table 31.

The fenestration area for an existing building shall equal the existing fenestration area prior to the proposed work and shall be distributed on each face of the building in the same proportions as the existing building.

Table 31. Baseline Building Vertical Fenestration Area

Building Area Types^(a)	Baseline Building Gross Above-Grade-Wall Area
Grocery Store	7%
Healthcare (outpatient)	21%
Hospital	27%
Hotel/motel (≤75 rooms)	24%
Hotel/motel (>75 rooms)	34%
Office (≤5000 ft2)	19%
Office (5000 to 50,000 ft2)	31%
Office (>50,000 ft2)	40%
Restaurant (quick service)	34%
Restaurant (full service)	24%
Retail (standalone)	11%
Retail (strip mall)	20%
School (primary)	22%
School (secondary and university)	22%
Warehouse (non-refrigerated)	6%

Horizontal Fenestration (Skylight) Geometry and Area
Applicability	All horizontal fenestration (skylights)
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: exterior shading is modeled from buildings, vegetation, other objects if daylighting is modeled within the adjacent space.
Baseline Building	G3.2 New Construction/Major Alterations The geometry of the horizontal fenestration shall be equal to the proposed design or 3% of gross roof area, whichever is smaller. If the skylight area of the proposed design exceeds 3%, the baseline skylight area shall be decreased by an identical percentage in all roof components in which skylights are located to reach 3%. Skylight orientation as tilt shall be the same as the proposed design. G3.3 Minor Alterations The fenestration area [vertical and skylights] shall equal the existing fenestration area prior to the proposed work and shall be distributed on each face of the building in the same proportions as the existing building.

Fenestration Construction

Applicability

All fenestration

Definition

A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, solar heat gain coefficient (SHGC), and visible light transmittance (VT). U-factor and SHGC inputs are whole-window values.

Units

Data structure: shall include at a minimum the following properties as specified by NFRC ratings:

U-factor: whole window U-factor
SHGC: whole window solar heat gain coefficient
VT: visible transmittance

Input Restrictions

The U-factor, SHGC, and VT for fenestration shall be modeled as certified and labeled in accordance with NFRC 100, 200, and 300, respectively. Unlabeled skylights shall be assigned the U-factors in Standard 90.1-2022, Normative Appendix A, Table A8.1-1 for the SHGCs and Table A8.1-2 for VTs. In addition, projects must account for linear and point thermal bridges identified according to Standard 90.1-2022 Section 5.5.5, see Section 3.5.2 for detail.

Unlabeled vertical fenestration, both operable and fixed, shall be assigned the U-factors, SHGCs, and VTs in Normative Appendix A, Table A8.2.

New buildings are required to comply with the ‘Envelope Backstop” according to Standard 90.1-2022 Section G1.2.1d. See Section 3.5 for detail.

Baseline Building

G3.2 New Construction/Major Alterations

The requirements for vertical fenestration U factor and SHGC are specified in Table 32 and Table 33 (Standard 90.1-2022 Tables G3.4-1 to Tables G3.4-8). The visible transmittance for horizontal and vertical fenestration is specified are specified in Table 35 and Table 36 (Standard 90.1-2022 Tables G3.4-1 to Tables G3.4-8).

G3.3 Minor Alterations

For fenestration included in the scope of the retrofit, the requirements for vertical and horizontal fenestration U factor, SHGC and visible transmittance are specified in Standard 90.1-2022 Tables 5.5-0 through 8 based on climate zone, conditioning category, and fenestration type unless exceptions apply. If an exception applies, then the relevant parameter shall be modeled the same in the baseline and proposed. For example, Standard 90.1-2022 Section 5.5.4.4.1 includes SHGC related exceptions for permanent shading, orientation, and location.

The following are relevant exceptions to 90.1 Section 5.1.4 and in these scenarios the fenestration shall be modeled the same in the baseline and proposed models.

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 is permitted to be either on the inside or outside of the existing glazing.
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.
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.

Table 32. Standard 90.1-2022 G3.2 U-factor Requirement for Vertical and Horizontal Fenestration

Climate Zone	Nonresidential		Residential		Semi-Heated
Climate Zone	Vertical	Horizontal	Vertical	Horizontal	Vertical	Horizontal
0 and 1	1.22	1.36	1.22	1.36	1.22	1.36
2	1.22	1.36	1.22	1.36	1.22	1.36
3	0.57	0.69	0.57	0.69	1.22	1.36
3C	1.22	1.36	1.22	1.36	1.22	1.36
4	0.57	0.69	0.57	0.58	1.22	1.36
5	0.57	0.69	0.57	0.69	1.22	1.36
6	0.57	0.69	0.57	0.58	1.22	1.36
7	0.57	0.69	0.57	0.69	1.22	1.36
8	0.46	0.58	0.46	0.58	1.22	0.81

Table 33. Standard 90.1-2022 G3.2 SHGC Requirement for Vertical Fenestration

Climate Zone	Nonresidential				Residential				Semi-Heated
Climate Zone	0-10%	10.1-20%	20.1-30%	30.1-40%	0-10%	10.1-20%	20.1-30%	30.1-40%	0-10%
0 and 1	0.25	0.25	0.25	0.25	0.25	0.25	0.25	0.25	0.40
2	0.25	0.25	0.25	0.25	0.39	0.25	0.25	0.25	0.40
3	0.39	0.25	0.25	0.25	0.39	0.39	0.25	0.25	0.40
3C	0.61	0.39	0.39	0.34	0.61	0.61	0.39	0.34	0.40
4	0.39	0.39	0.39	0.39	0.39	0.39	0.39	0.39	0.40
5	0.49	0.39	0.39	0.39	0.49	0.39	0.39	0.39	0.40
6	0.49	0.39	0.39	0.39	0.49	0.39	0.39	0.39	0.40
7	0.49	0.49	0.49	0.49	0.49	0.49	0.49	0.49	0.40
8	0.40	0.40	0.40	0.40	0.40	0.40	0.40	0.40	0.40

Table 34. Standard 90.1-2022 G3.2 SHGC Requirement for Horizontal Fenestration

Climate Zone	Nonresidential		Residential		Semi-Heated
Climate Zone	0-2%	2.1-5%	0-2%	2.1-5%	0-2%	2.1-5%
0 and 1	0.36	0.19	0.19	0.19	0.55		0.55
2	0.36	0.19	0.19	0.19	0.55		0.55
3	0.39	0.19	0.36	0.19	0.55		0.55
3C	0.61	0.39	0.39	0.19	0.55		0.55
4	0.49	0.39	0.36	0.19	0.55		0.55
5	0.49	0.39	0.49	0.39	0.55		0.55
6	0.49	0.49	0.49	0.39	0.55		0.55
7	0.68	0.64	0.64	0.64	0.55		0.55
8	0.55	0.55	0.55	0.55	0.55		0.55

Table 35. Standard 90.1-2022 G3.2 VT Requirement for Vertical Fenestration

Climate Zone	Nonresidential				Residential				Semi-Heated
Climate Zone	0-10%	10.1-20%	20.1-30%	30.1-40%	0-10%	10.1-20%	20.1-30%	30.1-40%	0-10%
0 and 1	0.28	0.28	0.28	0.28	0.28	0.28	0.28	0.28	0.44
2	0.28	0.28	0.28	0.28	0.28	0.28	0.28	0.28	0.44
3	0.43	0.28	0.28	0.28	0.43	0.43	0.28	0.28	0.44
3C	0.67	0.43	0.43	0.34	0.61	0.61	0.39	0.34	0.44
4	0.43	0.43	0.43	043	0.43	0.43	0.43	0.43	0.44
5	0.54	0.43	0.43	0.43	0.54	0.43	0.43	0.43	0.44
6	0.54	0.43	0.43	0.43	0.54	0.43	0.43	0.43	0.44
7	0.54	0.54	0.54	0.54	0.54	0.54	0.54	0.54	0.44
8	0.44	0.44	0.44	0.44	0.44	0.44	0.44	0.44	0.44

Table 36. Standard 90.1-2022 G3.2 VT Requirement for Horizontal Fenestration

Climate Zone	Nonresidential		Residential		Semi-Heated
Climate Zone	0-2%	2.1-5%	0-2%	2.1-5%	0-2%	2.1-5%
0 and 1	0.40	0.21	0.21	0.21	0.61		0.61
2	0.40	0.21	0.21	0.21	0.61		0.61
3	0.43	0.21	0.40	0.21	0.61		0.61
3C	0.67	0.43	0.43	0.21	0.61		0.61
4	0.54	0.43	0.40	0.21	0.61		0.61
5	0.54	0.43	0.54	0.43	0.61		0.61
6	0.54	0.54	0.54	0.43	0.61		0.61
7	0.75	0.70	0.70	0.70	0.61		0.61
8	0.61	0.61	0.61	0.61	0.61		0.61

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features that are documented in the construction documents and shade the glazing, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall. Objects that shade the building but are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. The software shall be capable of modeling vertical fins and overhangs. Recessed windows may also be modeled with side fins and overhangs.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than the inputs must match the construction documents
Baseline Building	G3.2 New Construction/Major Alterations The baseline building is modeled without external shading devices and as flush with the exterior wall. G3.3 Minor Alterations External shading devices shall be modeled the same in the baseline and proposed models.

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings, components, or treatments of the glazing materials are addressed through the fenestration construction building descriptor.
Units	Data structure: indicates the type of control, or blind schedule if applicable
Input Restrictions	Manual fenestration shading devices such as blinds or shades may be modeled or not, but if they are, they are required to be modeled the same in the baseline building, so that there is no credit. Automatically controlled fenestration shades or blinds may be modeled in the proposed design.
Baseline Building	Manual shades or blinds shall be modeled the same as in the proposed building. G3.2 New Construction/Major Alterations Automatically controlled fenestration shades or blinds will not be modeled in the baseline building. G3.3 Minor Alterations Automatically controlled fenestration shades or blinds shall be modeled the same in the baseline and proposed models.

Dynamic Glazing
Applicability	Fenestration with dynamic glazing
Definition	Dynamic glazing can vary the SHGC and VT of the glazing in response to a signal from an energy management system, direct sunlight on the glazing, or other inputs
Units	Unitless
Input Restrictions	Dynamic glazing can be modeled for the proposed design and controlled according to sequences specified in the construction documents. If controlled manually, then the proposed model is required to use the average of the minimum and maximum SHGC and VT.
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 For fenestration included in the scope of the retrofit, the requirements for vertical and horizontal fenestration SHGC and visible transmittance are specified in Standard 90.1-2022 Tables 5.5-0 through 8 based on climate zone, conditioning category, and fenestration type unless exceptions apply. These can be modeled as fixed at the requirements in Standard 90.1-2022 Tables 5.5-0 through 8 in the baseline.

SHGC Dim Fraction
Applicability	Fenestration with dynamic glazing
Definition	For dynamic glazing, this is the fraction of the SHGC when darkened to the SHGC during normal operation. This can be applied when the solar heat gain exceeds a specified threshold, or controlled by an electrical signal.
Units	Unitless
Input Restrictions	Between 0 and 1
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 Minor Alterations Not applicable

VT Dim Fraction
Applicability	Fenestration with dynamic glazing
Definition	For dynamic glazing, this is the fraction of the visible transmittance when darkened to the visible transmittance during normal operation. This can be applied when the solar heat gain exceeds a specified threshold, or controlled by an electrical signal.
Units	Unitless
Input Restrictions	Between 0 and 1
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 Minor Alterations Not applicable

Dynamic Solar Heat Gain Threshold
Applicability	Fenestration with automatically controlled dynamic glazing
Definition	For dynamic glazing, this is the solar heat gain threshold above which the dynamic glazing is active (darkened). When the solar heat gain drops below this threshold, the glazing is switched back to being inactive (clearest setting). Indoor and outdoor air temperatures (OATs) can also be used as setpoints for controlling the switchable solar heat gain threshold. This may be used in combination with the solar heat gain and illuminance thresholds for control. A flag may be used to indicate that this control is not used.
Units	Incident solar threshold (Btu/h-ft²)
Input Restrictions	As designed
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 Minor Alterations Not applicable

Switchable Space Temperature Threshold
Applicability	Fenestration with automatically controlled dynamic glazing
Definition	For dynamic glazing, this is the space temperature above which the dynamic glazing is active (darkened). When the space temperature drops below this threshold, the glazing is switched back to being inactive (clearest setting). Indoor and outdoor air temperatures are the setpoints required for controlling the dynamic solar heat gain threshold. This may be used in combination with the solar heat gain and illuminance thresholds for control. A flag may be used to indicate that this control is not used.
Units	°F
Input Restrictions	As designed
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 Minor Alterations Not applicable

Dynamic Illuminance Threshold
Applicability	Fenestration with automatically controlled dynamic glazing
Definition	For dynamic glazing, this is the illuminance threshold above which the dynamic glazing is regulated between active (darkened) and inactive (clearest setting). With a single illuminance setpoint, the dynamic glazing will adjust between the clearest and darkest setting to allow the desired illuminance level. A flag may be used to indicate that this control is not used.
Units	lux
Input Restrictions	As designed
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 Minor Alterations Not applicable

Dynamic Glazing Schedule
Applicability	Fenestration with dynamic glazing controlled by an electrical signal
Definition	For dynamic glazing, this is an hourly schedule for when the dynamic glazing is darkened, when controlled by an electrical signal
Units	Boolean: 1 if dynamic glazing is active (darkened); 0 if not active
Input Restrictions	0 or 1 for schedule values. As designed.
Baseline Building	G3.2 New Construction/Major Alterations Not applicable G3.3 Minor Alterations Not applicable

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface.
Units	Text, unique
Input Restrictions	No restrictions

Fenestration Type (Skylights)
Applicability	All skylights
Definition	This is a classification of skylights that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List: Glass skylight with curb; plastic skylight with curb; or skylights with no curb
Input Restrictions	No restrictions, other than the skylight types specified must agree with the construction documents or the as-built drawings.

Fenestration Geometry
Applicability	All fenestration
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.

Fenestration Construction
Applicability	All fenestration
Definition	A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, SHGC and VT . Data may be specified in other ways, however, as long as the data are supported by appropriate tests.
Units	Data structure: fenestration construction
Input Restrictions	Performance information for fenestration shall be developed from NFRC test procedures or shall be taken from the default values in Appendix A of the baseline standard. Values entered shall be consistent with the specifications and the construction documents.

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall, that are documented on the construction documents and shade the glazing. Objects that shade the building but that are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. See Shading of the Building Site.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than that the inputs must match the construction documents

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings or components or treatments of the glazing materials are addressed through the Fenestration Construction building descriptor.
Units	Data structure
Input Restrictions	Internal shading shall not be modeled in the proposed design, unless it is automatically controlled, based on input from an astronomical timeclock, an exterior pyronometer, or other sensors. The control algorithm shall be documented on the construction documents. Interior shades without automatic controls shall not be modeled.

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is fenestration that has a tilt of less than 60° from horizontal.

Fenestration Name
Applicability	All fenestration, optional input
Definition	A unique name or code that relates the fenestration to the design documents and a parent surface.
Units	Text, unique
Input Restrictions	No restrictions

Fenestration Type (Skylights)
Applicability	All skylights
Definition	This is a classification of skylights that determines the thermal performance and solar performance requirement for vertical fenestration.
Units	List: Glass skylight with curb; plastic skylight with curb; or skylights with no curb
Input Restrictions	No restrictions, other than the skylight types specified must agree with the construction documents or the as-built drawings.

Fenestration Geometry
Applicability	All fenestration
Definition	Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.
Units	Data structure: opening
Input Restrictions	There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions: 1) exterior shading is modeled from buildings, vegetation, other objects; or 2) if daylighting is modeled within the adjacent space.

Fenestration Construction
Applicability	All fenestration
Definition	A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, SHGC and VT . Data may be specified in other ways, however, as long as the data are supported by appropriate tests.
Units	Data structure: fenestration construction
Input Restrictions	Performance information for fenestration shall be developed from NFRC test procedures or shall be taken from the default values in Appendix A of the baseline standard. Values entered shall be consistent with the specifications and the construction documents.

External Shading Devices
Applicability	All fenestration
Definition	Devices or building features, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall, that are documented on the construction documents and shade the glazing. Objects that shade the building but that are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. See Shading of the Building Site.
Units	Data structure: opening shade
Input Restrictions	No restrictions other than that the inputs must match the construction documents

Internal Shading Devices
Applicability	All fenestration
Definition	Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings or components or treatments of the glazing materials are addressed through the Fenestration Construction building descriptor.
Units	Data structure
Input Restrictions	Internal shading shall not be modeled in the proposed design, unless it is automatically controlled, based on input from an astronomical timeclock, an exterior pyronometer, or other sensors. The control algorithm shall be documented on the construction documents. Interior shades without automatic controls shall not be modeled.