101.2.1 Appendices: The provisions in the Appendices C Group-U Agricultural Buildings, G Flood-Resistant Construction, and H Signs are adopted as part of the IBC.
102.5 Appendices: The provisions in the Appendices AF Radon Control Methods and AQ Tiny Houses are adopted as part of the IRC;
Table N1102.1.3.1 (R402(R402.1.3.1) | ||||||||||
MD Alternative Insulation Minimum R-Values and Fenestration Requirements by Componenta | ||||||||||
Climate Zone | Fenestration U-Factor b, i | Skylightb U-Factor | Glazed Fenestration SHGCb, e | Ceiling R-Value | Wood Frame Wall R-Valueg | Mass Wall R-Valueh | Floor R-Value | Basementc, g Wall R-Value | Slabd R-Value & Depth | Crawl Spacec, g Wall R-Value |
4 except Marine | 0.30 | 0.55 | 0.40 | 49 | 20 or 13+5h | 8/13 | 19 | 10ci or 13 | 10ci, 4ft | 10ci or 13 |
5 | 0.30i | 0.55 | 0.40 | 49 | 20 or 13+5h | 13/17 | 30 | 15ci or 19 or 13 + 5ci | 10ci, 4ft | 15ci or 19 Or 13 + 5ci |
For SI: 1 foot = 304.8 mm. | ||||||||||
ci = continuous insulation. | ||||||||||
a. R-values are minimums. U-factors and SHGC are maximums. Where insulation is installed in a cavity that is less than the label or design thickness of the insulation, the installed R-value of the insulation shall be not less than the R-value specified in the table. | ||||||||||
b. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestrations. Exception: In Climate Zones 0 through 3, skylights shall be permitted to be excluded from glazed fenestration SHGC requirements provided that the SHGC for such skylights does not exceed 0.30. | ||||||||||
c. "10ci or 13" means R-10 continuous insulation (ci) on the interior or exterior surface of the wall or R-13 cavity insulation on the interior side of the wall. "15ci or 19 or 13 & 5ci" means R-15 continuous insulation (ci) on the interior or exterior surface of the wall; or R-19 cavity insulation on the interior side of the wall; or R-13 cavity insulation on the interior of the wall in addition to R-5 continuous insulation on the interior or exterior surface of the wall. | ||||||||||
d. R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-value for slabs. as indicated in the table. The slab-edge insulation for heated slabs shall not be required to extend below the slab. | ||||||||||
e. There are no SHGC requirements in the Marine Zone. | ||||||||||
f. Basement wall insulation is not required in Warm Humid locations as defined by Figure R301.1 and Table R301.1. | ||||||||||
g. The first value is cavity insulation; the second value is continuous insulation. Therefore, as an example, "13 & 5" means R-13 cavity insulation plus R-5 continuous insulation. | ||||||||||
h. Mass walls shall be in accordance with Section R402.2.5. The second R-value applies where more than half of the insulation is on the interior of the mass wall. | ||||||||||
i. A maximum U-factor of 0.32 shall apply in Climate Zones 3 through 8 to vertical fenestration products installed in buildings located either: | ||||||||||
1. Above 4,000 feet in elevation, or | ||||||||||
2. In windborne debris regions where protection of openings is required by Section R301.2.1.2 of the International Residential Code. |
Table N1108.3 (R408.3) Additional Energy Features1 | |||
Energy Feature | Percentage Increase for Climate Zone 4 | Percentage Increase for Climate Zone 5 | |
1 | >= 2.5% reduction in total UA5 | 1% | 1% |
2 | >= 5% reduction in total UA5 | 2% | 3% |
3 | > 7.5% reduction in total UA5 | 2% | 3% |
4 | 0.22 U-factor windows5 | 3% | 4% |
5 | High performance cooling system (Greater than or equal to 18 SEER and 14 EER air conditioner)2 | 3% | 2% |
6 | High performance cooling system (Greater than or equal to 16 SEER and 12 EER air conditioner)2 | 3% | 3% |
7 | High performance gas furnace (Greater than or equal to 96 AFUE natural gas furnace)2 | 5% | 7% |
8 | High performance gas furnace (Greater than or equal to 92 AFUE natural gas furnace)2 | 4% | 5% |
9 | High performance heat pump system (Greater than or equal to 10 HSPF/18 SEER air source heat pump.)2 | 6% | 6% |
10 | High performance heat pump system (Greater than or equal to 9 HSPF/16 SEER air source heat pump.)2 | 5% | 5% |
11 | Ground source heat pump (Greater than or equal to 3.5 COP ground source heat pump.)2 | 6% | 8% |
12 | Fossil fuel service water heating system (Greater than or equal to 82 EF fossil fuel service water-heating system.) | 3% | 2% |
13 | High performance heat pump water heating system option (Greater than or equal to 2.9 UEF electric service waterheating system.) | 8% | 6% |
14 | High performance heat pump water heating system. (Greater than or equal to 3.2 UEF electric service water-heating system.) | 8% | 6% |
15 | Solar hot water heating system (Greater than or equal to 0.4 solar fraction solar water-heating system.) | 6% | 6% |
16 | More efficient HVAC distribution system. (100 percent of ductless thermal distribution system or hydronic thermal distribution system located completely inside the building thermal envelope.) | 10% | 12% |
17 | 100% of ducts in conditioned space. (100 percent of duct thermal distribution system located in conditioned space as defined by Section R403.3.2.) | 12% | 15% |
18 | Reduced total duct leakage. (When ducts are located outside conditioned space, the total leakage of the ducts, measured in accordance with R403.3.5, shall be in accordance with one of the following: a. Where air handler is installed at the time of testing, 2.0 cubic feet per minute per 100 square feet of conditioned floor area. b. Where air handler is not installed at the time of testing, 1.75 cubic feet per minute per 100 square feet of conditioned floor area.) | 1% | 1% |
19 | 2 ACH50 air leakage rate with ERV or HRV installed. (Less than or equal to 2.0 ACH50, with either an Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV) installed.)3 | 10% | 13% |
20 | 2 ACH50 air leakage rate with balanced ventilation. (Less than or equal to 2.0 ACH50, with balanced ventilation as defined in Section 202 of the 2021 International Mechanical Code.)4 | 4% | 5% |
21 | 1.5 ACH50 air leakage rate with ERV or HRV installed. (Less than or equal to 1.5 ACH50, with either an ERV or HRV installed.)4 | 12% | 15% |
22 | 1 ACH50 air leakage rate with ERV or HRV installed. (Less than equal to 1.0 ACH50, with either an ERV or HRV installed.) 4 | 14% | 17% |
23 | Energy Efficient Appliances (Minimum 3 appliances not to exceed 1 form each type with follow efficiencies. Refrigerator - Energy Star Program Requirements, Product Specification for Consumer Refrigeration Products, Version 5.1 (08/05/2021), Dishwasher - Energy Star Program Requirements for Residential Dishwashers, Version 6.0 (01/29/2016), Clothes Dryer - Energy Star Program Requirements, Product Specification for Clothes Dryers, Version 1.1 (05/05/2017) and Clothes Washer - Energy Star Program Requirements, Product Specification for Clothes Washers, Version 8.1 (02/05/2018) | 7% | 5% |
24 | Renewable Energy Measure.4 | 11% | 9% |
1. Energy efficiency percentage increases as established by PNNL. | |||
2. For multiple cooling systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the cooling design load. For multiple heating systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the heating design load. Increases to minimum efficiency requirements are limited to one selection. | |||
3. Minimum HRV and ERV requirements, measured at the lowest tested net supply airflow, shall be greater than or equal to 75 percent Sensible Recovery Efficiency (SRE), less than or equal to 1.1 cubic feet per minute per watt (0.03 m3/min/watt) and shall not use recirculation as a defrost strategy. In addition, the ERV shall be greater than or equal to 50 percent Latent Recovery/ Moisture Transfer (LRMT). | |||
4. Renewable energy resources shall be permanently installed that have the capacity to produce a minimum of 1.0 watt of on-site renewable energy per square foot of conditioned floor area. The installed capacity shall be in addition to any onsite renewable energy required by Section R404.4. To qualify for this option, one of the following forms of documentation shall be provided to the code official: | |||
a. Substantiation that the RECs associated with the on-site renewable energy are owned by, or retired on behalf of, the homeowner. | |||
b. A contract that conveys to the homeowner the RECs associated with the on-site renewable energy or conveys to the homeowner an equivalent quantity of RECs associated with other renewable energy. | |||
c. Reduction in total UA from lines 1, 2 or 3 and higher performance windows from line 4 are limited to a single selection. |
Table R402.1.3.1 | ||||||||||
MD Alternative Insulation Minimum R-Values and Fenestration Requirements by Componenta | ||||||||||
Climate Zone | Fenestration U-Factor b, i | Skylightb U-Factor | Glazed Fenestration SHGCb, e | Ceiling R-Value | Wood Frame Wall R-Valueg | Mass Wall R-Valueh | Floor R-Value | Basementc, g Wall R-Value | Slabd R-Value & Depth | Crawl Spacec, g Wall R-Value |
4 except Marine | 0.30 | 0.55 | 0.40 | 49 | 20 or 13+5h | 8/13 | 19 | 10ci or 13 | 10ci, 4ft | 10ci or 13 |
5 | 0.30i | 0.55 | 0.40 | 49 | 20 or 13+5h | 13/17 | 30 | 15ci or 19 or 13 + 5ci | 10ci, 4ft | 15ci or 19 Or 13 + 5ci |
For SI: 1 foot = 304.8 mm. | ||||||||||
ci = continuous insulation. | ||||||||||
a. R-values are minimums. U-factors and SHGC are maximums. Where insulation is installed in a cavity that is less than the label or design thickness of the insulation, the installed R-value of the insulation shall be not less than the R-value specified in the table. | ||||||||||
b. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestrations. Exception: In Climate Zones 0 through 3, skylights shall be permitted to be excluded from glazed fenestration SHGC requirements provided that the SHGC for such skylights does not exceed 0.30. | ||||||||||
c. "10ci or 13" means R-10 continuous insulation (ci) on the interior or exterior surface of the wall or R-13 cavity insulation on the interior side of the wall. "15ci or 19 or 13 & 5ci" means R-15 continuous insulation (ci) on the interior or exterior surface of the wall; or R-19 cavity insulation on the interior side of the wall; or R-13 cavity insulation on the interior of the wall in addition to R-5 continuous insulation on the interior or exterior surface of the wall. | ||||||||||
d. R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-value for slabs. as indicated in the table. The slab-edge insulation for heated slabs shall not be required to extend below the slab. | ||||||||||
e. There are no SHGC requirements in the Marine Zone. | ||||||||||
f. Basement wall insulation is not required in Warm Humid locations as defined by Figure R301.1 and Table R301.1. | ||||||||||
g. The first value is cavity insulation; the second value is continuous insulation. Therefore, as an example, "13 & 5" means R-13 cavity insulation plus R-5 continuous insulation. | ||||||||||
h. Mass walls shall be in accordance with Section R402.2.5. The second R-value applies where more than half of the insulation is on the interior of the mass wall. | ||||||||||
i. A maximum U-factor of 0.32 shall apply in Climate Zones 3 through 8 to vertical fenestration products installed in buildings located either: | ||||||||||
1. Above 4,000 feet in elevation, or | ||||||||||
2.In windborne debris regions where protection of openings is required by Section R301.2.1.2 of the International Residential Code. |
Energy Feature | Percentage Increase for Climate Zone 4 | Percentage Increase for Climate Zone 5 | |
1 | >= 2.5% reduction in total UA5 | 1% | 1% |
2 | >= 5% reduction in total UA5 | 2% | 3% |
3 | > 7.5% reduction in total UA5 | 2% | 3% |
4 | 0.22 U-factor windows5 | 3% | 4% |
5 | High performance cooling system (Greater than or equal to 18 SEER and 14 EER air conditioner)2 | 3% | 2% |
6 | High performance cooling system (Greater than or equal to 16 SEER and 12 EER air conditioner)2 | 3% | 3% |
7 | High performance gas furnace (Greater than or equal to 96 AFUE natural gas furnace)2 | 5% | 7% |
8 | High performance gas furnace (Greater than or equal to 92 AFUE natural gas furnace)2 | 4% | 5% |
9 | High performance heat pump system (Greater than or equal to 10 HSPF/18 SEER air source heat pump.)2 | 6% | 6% |
10 | High performance heat pump system (Greater than or equal to 9 HSPF/16 SEER air source heat pump.)2 | 5% | 5% |
11 | Ground source heat pump (Greater than or equal to 3.5 COP ground source heat pump.)2 | 6% | 8% |
12 | Fossil fuel service water heating system (Greater than or equal to 82 EF fossil fuel service water-heating system.) | 3% | 2% |
13 | High performance heat pump water heating system option (Greater than or equal to 2.9 UEF electric service waterheating system.) | 8% | 6% |
14 | High performance heat pump water heating system. (Greater than or equal to 3.2 UEF electric service water-heating system.) | 8% | 6% |
15 | Solar hot water heating system (Greater than or equal to 0.4 solar fraction solar water-heating system.) | 6% | 6% |
16 | More efficient HVAC distribution system. (100 percent of ductless thermal distribution system or hydronic thermal distribution system located completely inside the building thermal envelope.) | 10% | 12% |
17 | 100% of ducts in conditioned space. (100 percent of duct thermal distribution system located in conditioned space as defined by Section R403.3.2.) | 12% | 15% |
18 | Reduced total duct leakage. (When ducts are located outside conditioned space, the total leakage of the ducts, measured in accordance with R403.3.5, shall be in accordance with one of the following: a. Where air handler is installed at the time of testing, 2.0 cubic feet per minute per 100 square feet of conditioned floor area. b. Where air handler is not installed at the time of testing, 1.75 cubic feet per minute per 100 square feet of conditioned floor area.) | 1% | 1% |
19 | 2 ACH50 air leakage rate with ERV or HRV installed. (Less than or equal to 2.0 ACH50, with either an Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV) installed.)3 | 10% | 13% |
20 | 2 ACH50 air leakage rate with balanced ventilation. (Less than or equal to 2.0 ACH50, with balanced ventilation as defined in Section 202 of the 2021 International Mechanical Code.)4 | 4% | 5% |
21 | 1.5 ACH50 air leakage rate with ERV or HRV installed. (Less than or equal to 1.5 ACH50, with either an ERV or HRV installed.)4 | 12% | 15% |
22 | 1 ACH50 air leakage rate with ERV or HRV installed. (Less than equal to 1.0 ACH50, with either an ERV or HRV installed.) 4 | 14% | 17% |
23 | Energy Efficient Appliances (Minimum 3 appliances not to exceed 1 form each type with follow efficiencies. Refrigerator - Energy Star Program Requirements, Product Specification for Consumer Refrigeration Products, Version 5.1 (08/05/2021), Dishwasher - Energy Star Program Requirements for Residential Dishwashers, Version 6.0 (01/29/2016), Clothes Dryer - Energy Star Program Requirements, Product Specification for Clothes Dryers, Version 1.1 (05/05/2017) and Clothes Washer - Energy Star Program Requirements, Product Specification for Clothes Washers, Version 8.1 (02/05/2018) | 7% | 5% |
24 | Renewable Energy Measure.4 | 11% | 9% |
1. Energy efficiency percentage increases as established by PNNL. | |||
2. For multiple cooling systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the cooling design load. For multiple heating systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the heating design load. Increases to minimum efficiency requirements are limited to one selection. | |||
3. Minimum HRV and ERV requirements, measured at the lowest tested net supply airflow, shall be greater than or equal to 75 percent Sensible Recovery Efficiency (SRE), less than or equal to 1.1 cubic feet per minute per watt (0.03 m3/min/watt) and shall not use recirculation as a defrost strategy. In addition, the ERV shall be greater than or equal to 50 percent Latent Recovery/ Moisture Transfer (LRMT). | |||
4. Renewable energy resources shall be permanently installed that have the capacity to produce a minimum of 1.0 watt of on-site renewable energy per square foot of conditioned floor area. The installed capacity shall be in addition to any onsite renewable energy required by Section R404.4. To qualify for this option, one of the following forms of documentation shall be provided to the code official: | |||
a. Substantiation that the RECs associated with the on-site renewable energy are owned by, or retired on behalf of, the homeowner. | |||
b. A contract that conveys to the homeowner the RECs associated with the on-site renewable energy or conveys to the homeowner an equivalent quantity of RECs associated with other renewable energy. | |||
c. Reduction in total UA from lines 1, 2 or 3 and higher performance windows from line 4 are limited to a single selection. |
Md. Code Regs. 09.12.51.04