Illinois Radon Resistant Construction Act

A new duplex

A builder begins original construction of a duplex in an Illinois county that the buyer believes has low radon potential. The builder argues that no passive pipe is necessary because no elevated test exists.

1. A duplex is a dwelling containing two apartments.
2. The project is original construction in Illinois.
3. The statewide mandate is not limited to selected radon zones.
4. The construction duty does not depend on a preconstruction indoor-air result.
5. Passive radon-resistant construction must be included.

Answer: The new duplex is covered statewide and requires the passive construction package.

A large new apartment building

A developer constructs a new 40-unit apartment building and asks whether the definition in 420 ILCS 52 automatically controls the project.

1. The project is original residential construction.
2. However, the statutory definition names a single-family home or dwelling containing two or fewer apartments, condominiums, or townhouses.
3. Forty apartments exceed that stated scope.
4. The Act's specific definition therefore does not automatically cover the project.
5. Other state codes, local ordinances, financing rules, or voluntary standards still require review.

Answer: The 40-unit building is outside this Act's stated new-residential-construction definition, but other requirements may apply.

The pipe has no fan

A buyer sees a labeled pipe running from beneath the slab through the attic and above the roof. There is an outlet and open pipe space in the attic but no fan.

1. The below-slab-to-roof path is consistent with passive construction.
2. The outlet and attic space prepare for future activation.
3. The absence of a fan means it is not an active soil-depressurization system.
4. Natural airflow can occur without powered suction.
5. A valid radon test is still needed to know the indoor concentration.

Answer: The facts describe a passive, fan-ready radon system, not proof of active mitigation or a low reading.

The builder wants to add the fan

After a new home tests at 6.2 pCi/L, the general contractor offers to install a vent fan personally because the passive pipe is already present. The contractor has no radon mitigation license. The contractor is working for the buyer, not on a dwelling in which the contractor resides.

1. The test result raises a mitigation concern under current health guidance.
2. The passive pipe makes conversion easier but does not expand the builder's legal scope.
3. Section 25 reserves the stated fan installation and passive-to-active upgrade to a radon contractor with appropriate mitigation authority.
4. The general contractor is not stated to hold that license.
5. A licensed radon contractor should design and perform the activation.

Answer: The unlicensed general contractor may not perform the fan upgrade; use a licensed radon contractor.

Two separated foundation areas

A covered home has a basement and a crawlspace separated so soil gas cannot move freely between their collection areas. The plan uses one pipe only beneath the basement slab and no crawlspace membrane path.

1. The basement calls for a sub-slab collection path.
2. The earth-floor crawlspace calls for a sealed sub-membrane path.
3. Separated foundation areas cannot be assumed to communicate.
4. The combination-foundation rule calls for separate radon vent pipes in the foundation areas or a continuous drain-tile connection, with the specified common outlet.
5. The current one-pipe basement-only plan leaves the crawlspace unserved.

Answer: Have the qualified designer or installer address both foundation types under the applicable rule. A basement-only pipe does not establish that the separate crawlspace is served.

The inspection passed but no one tested

A local official confirms the passive components in a new home satisfy the adopted construction code. The seller then advertises the home as tested radon safe, although no indoor-air measurement occurred.

1. The official confirmed construction compliance, not an air concentration.
2. Passive features resist entry and prepare for mitigation.
3. Radon cannot be detected by the senses.
4. Only a measurement produces a pCi/L result.
5. The advertised claim is unsupported by the inspection alone.

Answer: Do not claim the home was tested or is radon safe. State the verified passive features and obtain a valid measurement for concentration claims.

Exactly 4.0 counts

A valid radon report for a new home is 4.0 pCi/L. The seller says no reduction is recommended because the result must be greater than 4.0.

1. The action wording is 4.0 pCi/L or more.
2. Exactly 4.0 meets that threshold.
3. The result supports the reduction recommendation; it does not by itself decide who must pay under a contract.

Answer: The seller's threshold statement is wrong. Address the result with an appropriately licensed radon professional and the actual transaction terms.

The buyer wants a guarantee from the pipe

A seller supplies the passive-system installation record but has no radon test. The buyer asks the broker to promise that the air measures below the action level.

1. Installation evidence and air measurement are different evidence.
2. A construction record does not supply a pCi/L result.
3. The broker should describe the verified feature without inventing a test or a guarantee.

Answer: Explain what the record shows and arrange appropriate measurement under the transaction terms. Do not promise a result from the pipe alone.

The wrong credential for the fan

A person holds only a radon measurement credential and offers to activate a client's new-construction system, relying on the statutory label radon contractor.

1. The construction Act's definition refers to licensed measurement or mitigation work.
2. Part 422 separately recognizes measurement and mitigation categories.
3. The actual work requires the appropriate mitigation authority; a broad label does not expand a measurement-only credential.

Answer: Verify the appropriate mitigation qualification before assigning the activation. Measurement authority alone is not enough.

A resident tests the home

A person uses a radon kit in the dwelling where the person resides. Another student says every unlicensed resident measurement is forbidden.

1. Section 422.30(a) provides a resident exemption from the Part's licensing requirements.
2. That is different from offering testing services for someone else's property.
3. A licensing exemption also does not establish that a test followed the appropriate protocol.

Answer: The absolute licensing claim is incorrect. Apply the resident exemption and the actual measurement requirements.

Passive work and a separate sales disclosure

A covered new home has passive features. In an otherwise covered sale, the seller wants to omit the radon information and disclosure because the construction requirement was met.

1. The construction duty and the sales-disclosure duty arise under different provisions.
2. Passive features are not a test result or an automatic Section 20 sales-disclosure exclusion.
3. Section 10 governs the applicable sales information and disclosure timing.

Answer: Complete the applicable disclosure duties separately. Construction compliance alone is not an exemption from them.

Sand is not the whole listed option

A covered slab plan uses four inches of sand but omits the geotextile drainage matting. It claims compliance only with the listed sand option, with no demonstrated alternative design.

1. The sand option in Section 422.160(b)(2) includes the specified matting.
2. A four-inch depth does not erase the rest of that option.
3. A separate demonstrated-capability alternative cannot simply be assumed.

Answer: The stated sand-only facts do not establish the listed option. Have the qualified project professional verify and correct the design.

1. Which project is new residential construction under 420 ILCS 52?

1. An ordinary remodel of an existing duplex
2. An ordinary addition that does not create a new dwelling
3. Original construction of an Illinois duplex
4. Original construction of one 40-apartment dwelling

2. What powers a passive radon-resistant system?

1. A sump pump motor
2. A mandatory vent fan
3. A furnace blower
4. Natural convective airflow

3. Who may install passive radon-resistant construction during a covered new build?

1. Only a radon measurement professional, with no builder permission
2. The residential builder, subcontractors, or a radon contractor
3. Only the county building inspector personally
4. Only a radon mitigation professional, with no builder permission

4. Who has the required authority for a client's new-construction passive-to-active radon fan upgrade under the stated rule?

1. Any unlicensed electrician
2. The listing broker
3. A radon contractor with appropriate mitigation authority
4. Any home inspector

5. What does code-compliant passive construction prove about indoor radon concentration?

1. Nothing specific until the home is tested
2. A measured result that remains valid after every building alteration
3. A substitute for all later indoor-air measurements
4. A guarantee that the concentration is below 4.0 pCi/L

6. A valid new-home test result is exactly 4.0 pCi/L. Which statement matches Illinois and EPA action guidance?

1. The number is a guarantee of no health risk
2. Reduction is recommended only above 4.0
3. The result meets the 4.0-or-more action level
4. The passive pipe cancels the result

7. A covered new duplex is in a county thought to have low radon potential. No elevated indoor test exists. Which is correct?

1. The statewide passive requirement still applies
2. Passive construction may always be omitted
3. A neighbor's low result exempts the project
4. Only the buyer's preference controls the statutory duty

8. A person tests the dwelling where that person resides. Which statement is supported by Rule 422.30(a)?

1. The resident exemption applies only if the test result is below 4.0 pCi/L
2. A resident licensing exemption exists, but it does not establish protocol compliance or client-service authority
3. Every resident needs a measurement license for the dwelling where the resident lives
4. The resident exemption authorizes paid testing in other people's homes

9. A covered slab design relies only on the listed four-inch sand option but omits its drainage matting. No demonstrated alternative is established. Which follows?

1. Sand alone does not establish the specified sand-plus-matting option
2. The radon disclosure form replaces the layer
3. The builder license waives the matting
4. Depth alone satisfies every part of that option

10. A seller in an otherwise covered sale supplies passive-system paperwork and wants to skip the applicable radon disclosure. Which is correct?

1. Apply the separate disclosure duties; construction alone does not eliminate them
2. Disclosure may always wait until closing because the passive features exist
3. A construction record automatically replaces all prior elevated test records
4. Passive construction automatically creates a disclosure exclusion

11. A system indicator appears normal after fan activation. No post-mitigation air test is available. What is the sound conclusion?

1. The air concentration is exactly zero
2. Every below-grade room must have the same result
3. Equipment status does not establish the indoor radon concentration
4. A pressure indicator is the same as a radon detector

12. A developer asks only whether a new 40-apartment building falls within the definition in 420 ILCS 52/15. Which is correct?

1. It is outside this Act's stated dwelling definition, while other applicable requirements still need review
2. Only the buyer's preferred label determines coverage
3. It is automatically within the two-or-fewer-unit definition
4. It is exempt from every radon or building requirement