| Below Grade Wall Name | |
| Applicability | All projects, optional input |
|---|---|
| Definition | A unique name that keys the below grade wall to the construction documents |
| Units | Text, unique |
| Input Restrictions | None |
| Baseline Rules | Not applicable |
| Below Grade Wall Geometry | |
| Applicability | All projects |
|---|---|
| Definition | A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width. |
| Units | Data structure: below grade wall geometry |
| Input Restrictions | There are no restrictions other than that the inputs shall be in agreement with the construction documents. |
| Baseline Rules | The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design. |
| Below Grade Wall Construction | |
| Applicability | All projects, required input |
|---|---|
| Definition | A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions. |
| Units | Data structure: construction assembly |
| Input Restrictions | No restrictions other than that the inputs shall be in agreement with the construction documents. |
| Baseline Rules | See [bookref id="baseline-building-c-factor-criteria-for-below-grade-walls"] and [bookref id="baseline-building-below-grade-wall-construction-assemblies"]. |
[table title="Baseline Building C-factor Criteria for Below-Grade Walls" id="baseline-building-c-factor-criteria-for-below-grade-walls"]
| Applicable Standard | Space Category | Climate Zone | Standard Design | |
| Minimum Insulation | C-Factor | |||
| 90.1 - 2001 | Nonresidential | 1- 6 | NR | 1.140 |
| 7, 8 | R-7.5 c.i. | 0.119 | ||
| Residential | 1-5 | NR | 1.140 | |
| 6- 8 | R-7.5 c.i. | 0.119 | ||
| Semi-Heated | 1-8 | NR | 1.140 | |
| 90.1 - 2007 | Nonresidential | 1- 4 | NR | 1.140 |
| 5678 | R-7.5 c.i. | 0.119 | ||
| Residential | 1-3 | NR | 1.140 | |
| 456 | R-7.5 c.i. | 0.119 | ||
| 7 | R-10 c.i. | 0.092 | ||
| 8 | R-12.5 c.i. | 0.075 | ||
| Semi-Heated | 1- 8 | NR | 1.140 | |
[table title="Baseline Building Below-Grade Wall Construction Assemblies" id="baseline-building-below-grade-wall-construction-assemblies"]
| Construction | Layer | Thickness (inch) | Conductivity (Btu/h ft F) | Density (lb/ft²) | Specific Heat (Btu/lb F) | R-value (ft²·°F·h/Btu) | C-factor (Btu/ft²·°F·h) |
| NR | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | 1.140 |
| R-7.5 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 1.8 | 0.02 | 1.8 | 0.29 | 7.50 | ||
| Total assembly | 8.37 | 0.119 | |||||
| R-10 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 2.4 | 0.02 | 1.8 | 0.29 | 10.00 | ||
| Total assembly | 10.87 | 0.092 | |||||
| R-12.5 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 3.0 | 0.02 | 1.8 | 0.29 | 12.50 | ||
| Total assembly | 13.37 | 0.075 |
| Below Grade Wall Name | |
| Applicability | All projects, optional input |
|---|---|
| Definition | A unique name that keys the below grade wall to the construction documents |
| Units | Text, unique |
| Input Restrictions | None |
| Baseline Rules | Not applicable |
| Below Grade Wall Geometry | |
| Applicability | All projects |
|---|---|
| Definition | A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width. |
| Units | Data structure: below grade wall geometry |
| Input Restrictions | There are no restrictions other than that the inputs shall be in agreement with the construction documents. |
| Baseline Rules | The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design. |
| Below Grade Wall Construction | |
| Applicability | All projects, required input |
|---|---|
| Definition | A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions. |
| Units | Data structure: construction assembly |
| Input Restrictions | No restrictions other than that the inputs shall be in agreement with the construction documents. |
| Baseline Rules | See [bookref id="baseline-building-c-factor-criteria-for-below-grade-walls"] and [bookref id="baseline-building-below-grade-wall-construction-assemblies"]. |
[table title="Baseline Building C-factor Criteria for Below-Grade Walls" id="baseline-building-c-factor-criteria-for-below-grade-walls"]
| Applicable Standard | Space Category | Climate Zone | Standard Design | |
| Minimum Insulation | C-Factor | |||
| 90.1 - 2007 | Nonresidential | 1- 4 | NR | 1.140 |
| 5678 | R-7.5 c.i. | 0.119 | ||
| Residential | 1-3 | NR | 1.140 | |
| 456 | R-7.5 c.i. | 0.119 | ||
| 7 | R-10 c.i. | 0.092 | ||
| 8 | R-12.5 c.i. | 0.075 | ||
| Semi-Heated | 1- 8 | NR | 1.140 | |
[table title="Baseline Building Below-Grade Wall Construction Assemblies" id="baseline-building-below-grade-wall-construction-assemblies"]
| Construction | Layer | Thickness (inch) | Conductivity (Btu/h ft F) | Density (lb/ft²) | Specific Heat (Btu/lb F) | R-value (ft²·°F·h/Btu) | C-factor (Btu/ft²·°F·h) |
| NR | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | 1.140 |
| R-7.5 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 1.8 | 0.02 | 1.8 | 0.29 | 7.50 | ||
| Total assembly | 8.37 | 0.119 | |||||
| R-10 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 2.4 | 0.02 | 1.8 | 0.29 | 10.00 | ||
| Total assembly | 10.87 | 0.092 | |||||
| R-12.5 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 3.0 | 0.02 | 1.8 | 0.29 | 12.50 | ||
| Total assembly | 13.37 | 0.075 |
| Below Grade Wall Name | |
| Applicability | All projects, optional input |
|---|---|
| Definition | A unique name that keys the below grade wall to the construction documents |
| Units | Text, unique |
| Input Restrictions | None |
| Baseline Rules | Not applicable |
| Below Grade Wall Geometry | |
| Applicability | All projects |
|---|---|
| Definition | A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width. |
| Units | Data structure: below grade wall geometry |
| Input Restrictions | There are no restrictions other than that the inputs shall be in agreement with the construction documents. |
| Baseline Rules | The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design. |
| Below Grade Wall Construction | |
| Applicability | All projects, required input |
|---|---|
| Definition | A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions. |
| Units | Data structure: construction assembly |
| Input Restrictions | No restrictions other than that the inputs shall be in agreement with the construction documents. |
| Baseline Rules | See Table 6.5.8-1 and Table 6.5.8-2. |
Table 6.5.8-1: Baseline Building C-factor Criteria for Below-Grade Walls
| Applicable Standard | Space Category | Climate Zone | Standard Design | |
| Minimum Insulation | C-Factor | |||
| 90.1 - 2007 | Nonresidential | 1- 4 | NR | 1.140 |
| 5678 | R-7.5 c.i. | 0.119 | ||
| Residential | 1-3 | NR | 1.140 | |
| 456 | R-7.5 c.i. | 0.119 | ||
| 7 | R-10 c.i. | 0.092 | ||
| 8 | R-12.5 c.i. | 0.075 | ||
| Semi-Heated | 1- 8 | NR | 1.140 | |
Table 6.5.8-2: Baseline Building Below-Grade Wall Construction Assemblies
| Construction | Layer | Thickness (inch) | Conductivity (Btu/h ft F) | Density (lb/ft²) | Specific Heat (Btu/lb F) | R-value (ft²·°F·h/Btu) | C-factor (Btu/ft²·°F·h) |
| NR | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | 1.140 |
| R-7.5 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 1.8 | 0.02 | 1.8 | 0.29 | 7.50 | ||
| Total assembly | 8.37 | 0.119 | |||||
| R-10 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 2.4 | 0.02 | 1.8 | 0.29 | 10.00 | ||
| Total assembly | 10.87 | 0.092 | |||||
| R-12.5 c.i. | 115 lb/ft3 CMU, solid grout | 8 | 0.45 | 115 | 0.20 | 0.87 | |
| R-10 continuous insulation | 3.0 | 0.02 | 1.8 | 0.29 | 12.50 | ||
| Total assembly | 13.37 | 0.075 |
Heat transfer from below-grade walls may be modeled using a constant annual or monthly ground temperature. The temperatures from table 3.9.1-1 may be used as a default.
|
Below-Grade Wall Name |
|
|---|---|
|
Applicability |
All projects, optional input |
|
Definition |
A unique name that keys the below grade wall to the construction documents |
|
Units |
Text, unique |
|
Input Restrictions |
None |
|
Baseline Rules |
Not applicable |
|
Below-Grade Wall Geometry |
|
|---|---|
|
Applicability |
All projects |
|
Definition |
A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width. |
|
Units |
Data structure: below grade wall geometry |
|
Input Restrictions |
There are no restrictions other than that the inputs shall be in agreement with the construction documents. |
|
Baseline Rules |
The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design. |
|
Below-Grade Wall Construction |
|
|---|---|
|
Applicability |
All projects, required input |
|
Definition |
A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions. |
|
Units |
Data structure: construction assembly |
|
Input Restrictions |
No restrictions other than that the inputs shall be in agreement with the construction documents. |
|
Baseline Rules |
See Table 3.5.8-1 and Table 3.5.8-2. |
Table 3.5.8-1: Baseline Building C-factor Criteria for Below-Grade Walls
|
|
Nonresidential |
Residential |
Semi-Heated |
|||
|
Climate Zone |
Name |
C-factor |
Name |
C-factor |
Name |
C-factor |
|
1 |
NR |
1.140 |
NR |
1.140 |
NR |
1.140 |
|
2 |
||||||
|
3 |
||||||
|
4 |
||||||
|
5 |
||||||
|
6 |
R-7.5 ci |
0.119 |
||||
|
7 |
R-7.5 ci |
0.119 |
||||
|
8 |
||||||
Table 3.5.8-2: Baseline Building Below-Grade Wall Construction Assemblies
|
Construction |
Layer |
Thickness (inch) |
Conductivity (Btu/h ft F) |
Density (lb/ft²) |
Specific Heat (Btu/lb F) |
R-value (ft²·°F·h/Btu) |
C-factor (Btu/ft²·°F·h) |
|
NR |
115 lb/ft3 CMU, solid grout |
8 |
0.45 |
115 |
0.20 |
0.87 |
1.140 |
|
R-7.5 c.i. |
115 lb/ft3 CMU, solid grout |
8 |
0.45 |
115 |
0.20 |
0.87 |
|
|
|
R-10 continuous insulation |
1.8 |
0.02 |
1.8 |
0.29 |
7.50 |
|
|
|
Total assembly |
|
|
|
|
8.37 |
0.119 |
|
Below-Grade Wall Name |
|
|
Applicability |
All projects, optional input |
|
Definition |
A unique name that keys the below-grade wall to the construction documents |
|
Units |
Text: unique |
|
Input Restrictions |
None |
|
Baseline Building |
Not applicable |
|
Below-Grade Wall Geometry |
|
|
Applicability |
All projects |
|
Definition |
A geometric construct that describes the dimensions and placement of walls located below grade. Below-grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models account for the depth below grade when estimating heat transfer, so the geometry may include height and width. |
|
Units |
Data structure: below-grade wall geometry |
|
Input Restrictions |
As designed |
|
Baseline Building |
Same as proposed |
|
Below-Grade Wall Construction |
|
|
Applicability |
All projects, required input |
|
Definition |
A specification containing a series of layers that result in a construction assembly for the proposed design. The first layer in the series represents the outside (or exterior) layer and the last layer represents the inside (or interior) layer. See the building descriptors above for below-grade wall construction type. |
|
Units |
Data structure: construction assembly The construction can be described as a C-factor, which is similar to a U-factor, except that the outside air film is excluded, or the construction can be represented as a series of layers, like exterior constructions. |
|
Input Restrictions |
As designed, with the construction assembly defined by a series of layers. Each layer specified, must consist of materials as described in Section 3.5.2. |
|
Baseline Building |
The baseline below grade wall construction shall be modeled as layers. The C-factor required for baseline wall construction is defined in Table 34. The layer by layer construction corresponding to each U-factor shall be modeled as shown in Table 35. For existing buildings, the baseline walls shall follow the same rules as new buildings. |
Table 34. Standard 90.1-2019 Requirements for Baseline Wall Construction for Non-Residential Space Conditioning Categories
|
Climate Zone |
Non-Residential C-factor (Minimum Insulation) |
Residential C-factors (Minimum Insulation) |
Semi Heated C-factors (Minimum Insulation) |
|
Climate Zone 1 |
C-1.140 (NR) |
C-1.140 (NR) |
C-1.140 (NR) |
|
Climate Zone 2 |
C-1.140 (NR) |
C-1.140 (NR) |
C-1.140 (NR) |
|
Climate Zone 3 |
C-1.140 (NR) |
C-1.140 (NR) |
C-1.140 (NR) |
|
Climate Zone 4 |
C-1.140 (NR) |
C-1.140 (NR) |
C-1.140 (NR) |
|
Climate Zone 5 |
C-1.140 (NR) |
C-1.140 (NR) |
C-1.140 (NR) |
|
Climate Zone 6 |
C-1.140 (NR) |
C-0.119 (R-7.5 c.i.) |
C-1.140 (NR) |
|
Climate Zone 7 |
C-0.119 (R-7.5 c.i.) |
C-0.119 (R-7.5 c.i.) |
C-1.140 (NR) |
|
Climate Zone 8 |
C-0.119 (R-7.5 c.i.) |
C-0.119 (R-7.5 c.i.) |
C-1.140 (NR) |
Table 35. Baseline Building Below-Grade Wall Construction Assemblies
|
Insulation |
Layer |
Thickness (inch) |
Conductivity (Btu/h ft °F) |
Density (lb/ft² ) |
Specific Heat (Btu/lb °F) |
R-value (ft²·°F·h/Btu) |
C-factor (Btu/ft²·°F·h) |
|
NR |
115 lb/ft3 CMU, solid grout |
8 |
0.45 |
115 |
0.20 |
0.87 |
1.140 |
|
R-7.5 c.i. |
115 lb/ft3 CMU, solid grout |
8 |
0.45 |
115 |
0.20 |
0.87 |
|
|
R-7.5 continuous insulation |
1.8 |
0.02 |
1.8 |
0.29 |
7.50 |
|
|
|
0.5 in. gypsum board |
0.5 |
|
|
|
0.45 |
|
|
|
Total assembly |
8.82 |
0.119 |
|||||
| Below Grade Wall Name | |
| Applicability | All projects, optional input |
|---|---|
| Definition | A unique name that keys the below grade wall to the construction documents |
| Units | Text, unique |
| Input Restrictions | None |
| Below Grade Wall Geometry | |
| Applicability | All projects |
|---|---|
| Definition | A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width. |
| Units | Data structure: below grade wall geometry |
| Input Restrictions | There are no restrictions other than that the inputs shall be in agreement with the construction documents. |
| Below Grade Wall Construction | |
| Applicability | All projects, required input |
|---|---|
| Definition | A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions. |
| Units | Data structure: construction assembly |
| Input Restrictions | No restrictions other than that the inputs shall be in agreement with the construction documents. |
| Below Grade Wall Name | |
| Applicability | All projects, optional input |
|---|---|
| Definition | A unique name that keys the below grade wall to the construction documents |
| Units | Text, unique |
| Input Restrictions | None |
| Below Grade Wall Geometry | |
| Applicability | All projects |
|---|---|
| Definition | A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width. |
| Units | Data structure: below grade wall geometry |
| Input Restrictions | There are no restrictions other than that the inputs shall be in agreement with the construction documents. |
| Below Grade Wall Construction | |
| Applicability | All projects, required input |
|---|---|
| Definition | A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions. |
| Units | Data structure: construction assembly |
| Input Restrictions | No restrictions other than that the inputs shall be in agreement with the construction documents. |