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LEED v4
Homes
Indoor Environmental Quality
Radon-resistant construction

LEED CREDIT

Homes-v4 EQp4: Radon-resistant construction Required

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SPECIAL REPORT

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© Copyright U.S. Green Building Council, Inc. All rights reserved.

Requirements

Case 1. New Construction
If the building is in EPA radon zone 1 (or local equivalent for projects outside the United States), design and build with radon-resistant construction techniques, as prescribed by American Association of Radon Scientist and Technologists (AARST), Reducing Radon in New Construction of 1 & 2 Family (RRNC 2.0); EPA Building Radon Out; NFPA 5000, Chapter 49; International Residential Code, Appendix F; CABO, Appendix F; ASTM E1465; or a local equivalent, whichever is more stringent. Follow all the requirements listed in Indoor airPLUS, 2.1:
  • Provide a capillary break per the Indoor airPLUS specifications.
  • Provide an electrical outlet near vent piping in the attic to facilitate future fan installation.
  • Install a 3- or 4-inch (or approximately 80- or 100- millimeters)diameter gas-tight vertical vent pipe with no bends greater than 45 degrees, connected to an open T-fitting in the aggregate layer, extending up through the conditioned spaces and terminating at least 12 inches (300 millimeters) above the roof opening./li>
The requirements for radon protection are automatically satisfied if the building is elevated by at least 2 feet (600 millimeters), with open air space between the building and ground. An enclosed vented crawlspace does not qualify. A garage under a building is an acceptable alternative. For mixed-use buildings, nonresidential space is exempted.
Case 2. Renovation of Existing Building
If the building is in EPA radon zone 1 (high risk), and if no slab work is being performed (i.e., an existing slab is not being demolished, and no new slab floor is being built), test the building for radon. If the results are greater than 4 pCi/L, install an active ventilation system. If the results are less than 4 pCi/L, no radon-resistant construction techniques are required. Projects that earn the EPA Indoor airPLUS label automatically meet the requirements of this prerequisite.

Alternative Compliance Paths (ACPs)

Canada ACP - Radon
Cities in Canada that have been proven to have an average radon concentration of 4 pCi/L (150 Bq/m3) or less through testing in accordance with the Health Canada Guide for Radon Measurements in Dwellings (with a minimum of 50 tests) are considered equivalent to EPA Radon Zone 2, and therefore are exempted from the radon requirements of this prerequisite. See all forum discussions about this credit »

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Addenda

7/1/2014 – Updated: 3/29/2018
Regional ACP
Description of change:
Add the following as a Canada ACP under local equivalents for projects outside the U.S.

"Cities in Canada that have been proven to have an average radon concentration of 4 pCi/L (150 Bq/m3) or less through testing in accordance with the Health Canada Guide for Radon Measurements in Dwellings (with a minimum of 50 tests) are considered equivalent to EPA Radon Zone 2, and therefore are exempted from the radon requirements of this prerequisite."
Campus Applicable
No
Internationally Applicable:
Yes
10/14/2019
LEED Interpretation
Inquiry:

How does an international project meet the requirements of this prerequisite?

Ruling:

Choose one of the following options:
1. Assume the project is in a high-risk radon area and install a passive ventilation system as outlined in the prerequisite. This option is highly encouraged because installing a radon system after construction completion can be difficult.
2. Do not install a passive ventilation system and complete the following steps: Test for radon at the completion of the project using either a long-term or short-term test. For multiple residential buildings on a site, contact GBCI for sampling options.
• Long-term test (30+ day test): Conduct a single long-term test. If the result is less than 4 pCi/L (150 Bq/m3), no remediation is needed and the prerequisite is satisfied. If the result is 4 pCi/L (150 Bq/m3) or greater, install an active radon mitigation system. Once the active mitigation system is installed, undergo another test (short-term or long-term) to confirm that the mitigation system is operating as needed. OR;
• Short-term test (<30 day test): Conduct a short-term test. If the result is 4 pCi/L (150 Bq/m3) or less, no re-test or remediation is needed and the prerequisite is satisfied. If the result exceeds 4 pCi/L (150 Bq/m3), conduct remediation OR conduct a second short-term test. If the average of the two tests is 4 pCi/L (150 Bq/m3) or less, no re-test or remediation is needed and the prerequisite is satisfied. If the average of the two tests exceeds 4 pCi/L (150 Bq/m3), install an active radon mitigation system. Once the active mitigation system is installed, undergo another test (short-term or long-term) to confirm that the mitigation system is operating as needed.

3. Demonstrate project is in low-risk radon area via city test data. Cities that have been proven to have an average radon concentration of 4 pCi/L (150 Bq/m3) or less through testing (with a minimum of 50 tests) are considered equivalent to EPA radon zone 2. Projects located in these cities are therefore are exempted from the radon requirements of this prerequisite.

Campus Applicable
No
Internationally Applicable:
Yes
4/5/2016
LEED Interpretation
Inquiry:

Which LEED v4 Homes credit and prerequisite requirements can be automatically met by the EPA Indoor airPLUS program?

Ruling:

Projects that earn the EPA Indoor airPLUS label, based on Indoor airPLUS Version 1 (Rev 03) Construction Specifications automatically meet the requirements of the following prerequisites and credits:

EQ prerequisite Ventilation;
EQ prerequisite Combustion venting;
EQ prerequisite Garage pollutant protection;
EQ prerequisite Radon-resistant construction;
EQ prerequisite Air filtering;
EQ prerequisite Environmental tobacco smoke;
EQ credit Contaminant control, Option 3. Preoccupancy Flush (0.5 points);
EQ credit Enhanced combustion venting, Option 2. Enhanced combustion venting measures (1 point);
EQ credit Enhanced garage pollutant protection, Case 1. Single Family, Option 1. Exhaust Fan in Garage (1 point)
MR credit Durability management verification (1 point)
SS credit Nontoxic pest control (1 point) , measure: Seal all external cracks, joints, penetrations, edges, and entry points with appropriate caulking. Install rodent- and corrosion-proof screens (e.g., copper or stainless steel mesh) on all openings greater than ¼ inch (6 millimeters), except where code prohibits their installation (e.g., dryer vents), and measure: Design discharge points for rain gutters, air-conditioning condensation lines, steam vent lines, or any other moisture source such that discharge is at least 24 inches (600 millimeters) from the foundation.

In addition, project teams are eligible for an Innovation credit for additional moisture control items covered in Indoor airPLUS and not directly awarded in LEEDv4

Campus Applicable
No
Internationally Applicable:
No
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USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Requirements

Case 1. New Construction
If the building is in EPA radon zone 1 (or local equivalent for projects outside the United States), design and build with radon-resistant construction techniques, as prescribed by American Association of Radon Scientist and Technologists (AARST), Reducing Radon in New Construction of 1 & 2 Family (RRNC 2.0); EPA Building Radon Out; NFPA 5000, Chapter 49; International Residential Code, Appendix F; CABO, Appendix F; ASTM E1465; or a local equivalent, whichever is more stringent. Follow all the requirements listed in Indoor airPLUS, 2.1:
  • Provide a capillary break per the Indoor airPLUS specifications.
  • Provide an electrical outlet near vent piping in the attic to facilitate future fan installation.
  • Install a 3- or 4-inch (or approximately 80- or 100- millimeters)diameter gas-tight vertical vent pipe with no bends greater than 45 degrees, connected to an open T-fitting in the aggregate layer, extending up through the conditioned spaces and terminating at least 12 inches (300 millimeters) above the roof opening./li>
The requirements for radon protection are automatically satisfied if the building is elevated by at least 2 feet (600 millimeters), with open air space between the building and ground. An enclosed vented crawlspace does not qualify. A garage under a building is an acceptable alternative. For mixed-use buildings, nonresidential space is exempted.
Case 2. Renovation of Existing Building
If the building is in EPA radon zone 1 (high risk), and if no slab work is being performed (i.e., an existing slab is not being demolished, and no new slab floor is being built), test the building for radon. If the results are greater than 4 pCi/L, install an active ventilation system. If the results are less than 4 pCi/L, no radon-resistant construction techniques are required. Projects that earn the EPA Indoor airPLUS label automatically meet the requirements of this prerequisite.

Alternative Compliance Paths (ACPs)

Canada ACP - Radon
Cities in Canada that have been proven to have an average radon concentration of 4 pCi/L (150 Bq/m3) or less through testing in accordance with the Health Canada Guide for Radon Measurements in Dwellings (with a minimum of 50 tests) are considered equivalent to EPA Radon Zone 2, and therefore are exempted from the radon requirements of this prerequisite.
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