7 Costly Oversights in Multifamily Radon Compliance.

 

When it comes to multifamily construction, often times, radon testing isn’t optional—it’s a compliance and safety requirement. Yet many developers, property managers, and GCs unknowingly make mistakes that lead to costly retests, occupancy delays and even worse, tenant deaths.

Here are seven common oversights that can derail your project and how to avoid them.

1. Not Understanding HUD and/Or Lender Requirements.

HUD, Fannie Mae, Freddie Mac and private lenders all have strict radon testing requirements for multifamily housing. These standards go far beyond residential testing protocols.

Failure to follow them correctly often means:

  • Your report will not be accepted.

  • You’ll have to repeat the entire testing process

  • Your financing or closing can be delayed.


👉 Key takeaway: Verify your testing company is compliant with HUD and ANSI/AARST standards before starting.

2. Failing to Consider Budgets and Timelines

One of the most common oversights is leaving radon testing out of the initial budget and project schedule.

When testing is an afterthought, it usually results in:

  • Scheduling Conflicts – If testing isn’t considered with the construction schedule, it can clash with inspections, tenant move-ins, or lender deadlines.

  • Occupancy delays when TCO’s can’t be obtained on time

  • Compressed Turnaround Times – Unplanned radon testing the end of a project often forces results into a rushed window, increasing the risk of errors and delays.

👉 Key takeaway: Verify your testing company is experienced in adapting to unforeseen scheduling delays and seek to understand possible schedule change costs.

3. Ignoring Closed-Building Conditions

Radon testing requires Closed-Building Conditions, which means windows and exterior doors must remain closed (except for normal entry and exit).

When tenants, staff, or contractors ignore this rule, test results are invalid. Unfortunately, this mistake often isn’t caught until after testing is complete—when it’s too late. That means paying for another round of testing.

  • Workers & Tenants Propping Doors or Windows Open – Even a few hours of ventilation can cause test results to be thrown out, forcing a complete retest.

  • Contractors Disrupting Airflow – Ongoing work, like running fans or leaving entryways open during construction punch-out, can invalidate results

  • Lack of Clear Communication – When occupants or staff aren’t informed about testing rules, accidental violations are almost guaranteed, leading to wasted time and added costs.

👉 Key takeaway: When tenants, staff, or contractors ignore this rule, test results are invalid. Unfortunately, this mistake often isn’t caught until after testing is complete—when it’s too late. That means paying for another round of testing.

4. Using a Company Without a Written Quality Control Plan

The number one red flag when hiring a radon testing provider is the absence of a written quality control (QC) plan.

A proper QC plan explains how the company ensures accuracy, defensibility, and compliance for every multifamily project. Without it, test results may not be accepted by lenders like HUD or Fannie Mae, leaving you exposed to liability if results are ever challenged.

  • Defensible Results – A QC plan documents the methods used to ensure accuracy, giving lenders confidence in the data.

  • Regulatory Compliance – HUD, Fannie Mae, and ANSI/AARST standards require clear QC procedures; without them, results may be rejected.

  • Reduced Risk of Retesting – A written QC plan helps prevent errors that lead to costly retests and project delays.

👉 Key takeaway: Without a written QC plan, your results may not stand up to lender scrutiny, exposing you to liability and expensive retesting.

5. Overlooking Radon as a Marketable Benefit

Too many developers and property managers treat radon testing as just another compliance checkbox. In reality, it’s a powerful differentiator. Today’s tenants and buyers care deeply about health, wellness, and sustainability. Promoting a radon-safe building positions you ahead of competitors and can directly influence lease-up speed, occupancy rates, and resale value.

Failure to leverage radon testing often means:

  • Missing out on a compelling wellness-driven selling point.

  • Falling behind competitors who highlight safety in their marketing.

  • Losing tenant trust if radon is only addressed after problems arise.

👉 Key takeaway: Don’t hide your compliance—market it. Show tenants and buyers that your property is radon-safe and you’ll turn a mandatory requirement into a competitive advantage.

6. Not coordinating access with occupants or property staff

In properties under renovation or partial occupancy, GCs often fail to arrange access to all required units. Missed access points lead to incomplete or invalid test reports. Any good Radon Speialist should supply management with tenant notifiaction letters, but a good GC should follow up and ensure every area will be accessible.

Failure to coordinate access often means:

  • Entire tests must be repeated, costing time and money.

  • Frustrated tenants may feel blindsided by unannounced entry.

  • Delays in meeting lender or HUD compliance deadlines.

👉 Key takeaway: The right testing partner keeps everyone informed, ensuring smooth access, valid results, and eliminating the risk of costly repeat testing.

7. Forgetting the real cost. Human lives

Radon is not just a compliance issue—it’s a health crisis hiding in plain sight. As the second leading cause of lung cancer after smoking, radon claims more lives every year than drunk driving. Young children and the elderly are especially vulnerable, as their bodies are less able to withstand prolonged exposure to poor air quality.

  • Defensible Results – A QC plan documents the methods used to ensure accuracy, giving lenders confidence in the data.

  • Regulatory Compliance – HUD, Fannie Mae, and ANSI/AARST standards require clear QC procedures; without them, results may be rejected.

  • Reduced Risk of Retesting – A written QC plan helps prevent errors that lead to costly retests and project delays.

👉 Key takeaway: Without a written QC plan, your results may not stand up to lender scrutiny, exposing you to liability and expensive retesting

👉 Bottom line: Radon compliance in multifamily housing isn’t just about passing a test—it’s about protecting lives, meeting strict HUD and lender requirements, and turning health and safety into a marketable advantage. The cost of oversight can be measured in delays, lost financing, wasted budgets, and most importantly, human lives. That’s why working with the right partner matters. The Radon Boss is the U.S.’s only radon service company with roots in multifamily development and construction—bringing unmatched insight into how buildings are designed, built, and operated. With us, compliance isn’t a headache—it’s a seamless, value-building process that keeps your project on time, on budget, and above all, safe.

About The Radon Boss, LLC​

Family owned & operated, The Radon Boss LLC adheres to the strictest standards and protocols to routinely deliver verifieable test results.

 

radon is A Silent Killer

 

21,000 Annual Deaths -

2nd Leading Cause of Lung Cancer