Radon testing for multifamily code compliance, LIHTC, HUD, and ANSI/AARST standards — third-party measurement with calibrated continuous radon monitors, NCI-formatted reports, and the certified test result that satisfies the program of record.
Radon is a colorless, odorless, radioactive gas that occurs naturally in soil and rock. It enters buildings through foundation cracks, sump pumps, and other penetrations, and it is the leading cause of lung cancer among non-smokers. The EPA recommends indoor radon levels below 4 pCi/L (picocuries per liter), and most state building codes require radon-resistant construction in multifamily and new residential construction.
Radon testing is the field measurement of indoor radon levels using a calibrated continuous radon monitor (CRM) or a charcoal canister. The measurement is run over a defined period (typically 48–96 hours for CRM, 2–7 days for charcoal), and the result is compared to the EPA action level (4 pCi/L) or the program target. The deliverable of record is a certified report that satisfies the program of record, the lender, the code inspector, and the property buyer.
HECS delivers radon testing for multifamily code compliance, LIHTC, HUD, USDA, and ANSI/AARST standards. We use calibrated continuous radon monitors (Sun Nuclear, Radonova, or equivalent) with current calibration certificates. The certified report is accepted by code inspectors, LIHTC syndicators, HUD funders, and the property buyer — on both new construction and existing buildings.
HECS delivers three radon testing scopes depending on the project phase, the program of record, and whether the engagement is paired with a mitigation system or a certification program.
New construction & existing
Radon testing per ANSI/AARST multifamily standards, state building code, and HUD multifamily requirements. CRM testing on a defined sample of units, common areas, and below-grade spaces.
Best for: Multifamily code, LIHTC, HUD, USDA
Pre-construction + post
Pre-construction radon-resistant construction (RRC) verification, post-construction radon testing, and the certified report that satisfies the state code and the program of record.
Best for: New residential, RRC, code compliance
Existing buildings
Radon testing for real estate transactions — buyer’s pre-purchase test, seller’s pre-listing test, and the certified report that satisfies the lender, the buyer, and the real estate transaction.
Best for: Existing buildings, real estate, transactions
From pre-test coordination to the certified report, here is what HECS delivers on a radon engagement.
HECS confirms the test scope, the program of record (multifamily code, LIHTC, HUD, real estate), the measurement locations, the measurement period, and the building-closed conditions required for the test. We coordinate with the GC, the property manager, and the program of record.
HECS deploys calibrated continuous radon monitors at the measurement locations, in closed-building conditions, for the defined period (typically 48–96 hours for multifamily, 48 hours for real estate). The CRM records the radon level, temperature, humidity, and barometric pressure at defined intervals.
HECS retrieves the CRM data, analyzes the result against the EPA action level (4 pCi/L) and the program target, and documents the test conditions, the instrument, the calibration, and the result. The analysis is the input to the certified report.
HECS issues the certified radon report: the instrument, the calibration date, the measurement locations, the measured values, the EPA action level comparison, the pass/fail status, and the NCI-formatted certification. The report is accepted by the code inspector, the LIHTC syndicator, the HUD funder, and the property buyer.
Every HECS radon report includes the following measurements and verifications, formatted to the program of record and the code of jurisdiction.
Calibrated continuous radon monitor (Sun Nuclear, Radonova, or equivalent) measures the radon level in pCi/L at defined intervals over the test period. The continuous data captures diurnal and weather-related variation.
Comparison of the measured radon level to the EPA action level of 4 pCi/L. Reported as pass/fail, with the recommended mitigation if the level exceeds the action level.
Verification of the test conditions: closed-building conditions, no temporary ventilation, no open windows, no operating HVAC during the test. Required for ANSI/AARST, code, and HUD compliance.
Current calibration certificate for the CRM, dated within 12 months. Reported with the certified test result.
For multifamily, below-grade spaces (basements, garages, mechanical rooms) and common areas are tested in addition to dwelling units. Per ANSI/AARST multifamily protocol.
For multifamily sampling, the test is run on a defined sample of units per ANSI/AARST or program-specific protocol. HECS designs the sampling plan with the project team.
A certified radon test is the deliverable that satisfies code compliance, releases the LIHTC or HUD funding, supports the real estate transaction, and protects the occupants from the leading cause of lung cancer among non-smokers.
Most state building codes require radon-resistant construction in multifamily and new residential construction. The certified radon test is the deliverable that satisfies the code inspector and releases the certificate of occupancy.
LIHTC, HUD, and USDA multifamily projects require radon testing as part of the funding application. HECS radon reports are accepted by all major LIHTC syndicators, HUD funders, and USDA RD projects.
For real estate transactions, a certified radon test is the deliverable that satisfies the lender, the buyer, and the real estate transaction. HECS delivers the test on a 48-hour turnaround with a certified report that closes with the transaction.
Indoor air quality at the level the design promised — verified, documented, and accepted by the certification program of record.
A radon-resistant construction (RRC) system reduces the radon level by 50%+ compared to a non-resistant building. The certified radon test is the deliverable that confirms the RRC system performs to design.
A certified third-party radon test transfers the radon risk from the GC, the owner, and the property seller to a neutral third party. It is the deliverable that satisfies the code inspector, releases the funding, and closes out the transaction.
HECS is an NCI-certified testing and balancing firm. We work with general contractors, mechanical contractors, property developers, and certification programs across the region — delivering field measurements, certified reports, and the documentation owners and inspectors actually need.
Every HECS field technician holds current NCI certification. We use calibrated instruments, follow NCI-formatted reporting, and produce the documentation that commissioning authorities, code inspectors, and certification programs accept on the first review.
HECS serves commercial, multifamily, institutional, and light-industrial projects across Kentucky, Indiana, Ohio, Tennessee, Illinois, and Missouri. We staff jobs of every size — from a single building balance to a 12-building multifamily rollout — with the same team and the same reporting standard.
Blower door, duct leakage, refrigerant charge, combustion analysis, decibel, infrared, TAB, and 45L documentation — HECS delivers all of them. One contract, one schedule, one set of reports that line up with each other and with the certification program of record.
HECS radon testing is the right fit for:
Tell us about the project — program, scope, schedule — and we will respond with a written proposal inside two business days.
Radon is a colorless, odorless, radioactive gas that occurs naturally in soil and rock. It enters buildings through foundation cracks, sump pumps, and other penetrations, and it is the leading cause of lung cancer among non-smokers. The EPA recommends indoor radon levels below 4 pCi/L.
The EPA action level for indoor radon is 4 pCi/L (picocuries per liter). The EPA recommends fixing the building if the radon level is at or above 4 pCi/L. HECS reports the measured level against the EPA action level and recommends mitigation if the level exceeds 4 pCi/L.
A continuous radon monitor (CRM) is a calibrated instrument that measures the radon level in pCi/L at defined intervals (typically hourly) over the test period. The continuous data captures diurnal and weather-related variation, which is why ANSI/AARST, HUD, and most state codes require CRM testing for multifamily.
ANSI/AARST is the American National Standards Institute / American Association of Radon Scientists and Technologists. ANSI/AARST standards define the multifamily radon testing protocol, the mitigation protocol, and the certification requirements. HECS delivers ANSI/AARST-compliant radon testing on multifamily projects.
Most CRM radon tests take 48–96 hours in closed-building conditions. Real estate transactions typically use a 48-hour test. Multifamily sampling uses a 96-hour test per ANSI/AARST protocol. HECS provides a project-specific schedule with the proposal.
Yes. Radon testing is commonly bundled with blower door, duct leakage, and the certification field tests on multifamily and LIHTC projects. HECS delivers the radon test + certification as a single integrated engagement.
The cost of radon mitigation depends on the building, the foundation type, and the mitigation system. HECS provides a project-specific mitigation estimate with the proposal. Call (859) 983-7382 for a project-specific quote.
The radon-resistant construction (RRC) credit is a credit on ENERGY STAR, NGBS, and EarthCraft for new residential construction that includes a passive radon-resistant foundation, a vent pipe, and an electrical rough-in for a future fan. The certified radon test confirms the RRC system performs to design.
A continuous radon monitor (CRM) records the radon level continuously over the test period, capturing diurnal and weather-related variation. A charcoal canister absorbs radon over a fixed period (typically 2–7 days) and is read in a lab. ANSI/AARST, HUD, and most state codes require CRM testing for multifamily.
Call (859) 983-7382 or email hecs@hecsusa.com with the project name, address, building type, the program of record, and the number of test locations. HECS responds with a written proposal inside two business days.
NCI-certified TAB that verifies design airflow and water flow at every terminal. Calibrated instruments, certified report.
Whole-building and duct leakage to RESNET, ENERGY STAR Multifamily, NGBS, and code. Blower door + duct tester.
Field verification, sampling, and documentation for ENERGY STAR MFNC. HECS is an ENERGY STAR MFNC verification partner.
Tell us about the project — program, scope, schedule — and we will respond with a written proposal inside two business days.
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