Establishing secure connection…Loading editor…Preparing document…

Radon Disclosure Addendum

This template is fully customizable. Edit the text, fill out the fields, and send it for signature. Give it a try!

RADON DISCLOSURE ADDENDUM

This Radon Disclosure Addendum supplements and is incorporated into the Purchase Agreement (or other binding agreement) for the property identified below. Seller discloses to Buyer the information set forth in this Addendum regarding radon gas and radon-related testing and mitigation. Capitalized terms not defined herein have the meanings given in the underlying agreement.

Property Identification

Parties

Seller Radon Disclosure

Seller hereby discloses to Buyer the following facts, known to Seller after reasonable inquiry, concerning radon gas in, on, or under the Property.

1. Previous radon testing was conducted at the Property:

If Yes, recorded test result: on by

2. A radon mitigation system is currently present on the Property:

If present, system installed by: on

3. Seller has provided Buyer with copies of available radon test reports and mitigation certificates:

Testing and Results

Test reports attached or provided:

Mitigation Details

System certification or warranty provided:

Buyer's Right to Test and Remedies

Buyer shall have the right to conduct independent radon testing during the inspection period provided in the underlying agreement. Buyer must notify Seller in writing of any test resulting in a level equal to or exceeding 4.0 picocuries per liter (pCi/L) within the inspection period to invoke remedies under this Addendum.

Inspection period (days): or Inspection deadline:

If test results are equal to or exceed 4.0 pCi/L, Buyer remedies (select one or more):

Representations and Indemnity

Seller represents that, to Seller's actual knowledge after reasonable inquiry, the information provided in this Addendum is true and complete. Seller shall disclose known material facts concerning radon, radon testing, and mitigation. Buyer acknowledges that acceptance of this Addendum and consummation of the transaction may limit or waive Buyer’s rights to later claim nondisclosure, except for fraud or intentional misrepresentation.

Each party agrees to indemnify and hold harmless the other party from claims, costs, or liabilities resulting from that party's breach of its representations hereunder, except to the extent caused by the indemnitee's negligence or willful misconduct.

Governing Law and Entire Agreement

This Addendum shall be governed by and construed in accordance with the laws of the state in which the Property is located. This Addendum, together with the underlying agreement, constitutes the entire agreement between the parties with respect to radon disclosure and supersedes any prior oral or written statements.

Acknowledgment

By signing below, Seller and Buyer acknowledge receipt of this Radon Disclosure Addendum, confirm that they have read and understand its contents, and agree that its terms are part of the transaction documents.

Seller:

By:

Date:

Buyer:

By:

Date:

Enter text✕
Prepare your document for signing right on this page
  • 01 Edit the text and complete the fields
  • 02 Click Sign Now and on the next screen add recipients and signature fields in SignNow
  • 03 Start your free trial to sign and send your doc
Sign Now

What the Radon Disclosure Addendum Is and When It Applies

The Radon Disclosure Addendum is a supplemental real estate form used to report known radon conditions, test results, and any mitigation measures for a specific property. It documents seller statements about radon levels (typically measured in picocuries per liter, pCi/L), identifies the testing method and date, and gives buyers a clear record to evaluate health and safety risks before closing. States vary on whether the addendum is mandatory, how it must be delivered, and whether it must be notarized or recorded, so parties should confirm local requirements when preparing and signing the addendum.

Why a Clear Radon Disclosure Matters to Transactions

A concise Radon Disclosure Addendum promotes transparency, reduces post-closing disputes, and helps buyers and sellers allocate responsibility for testing or mitigation. When delivered and retained properly it supports regulatory compliance and creates a searchable record that can be reproduced if needed under ESIGN and UETA standards.

Why a Clear Radon Disclosure Matters to Transactions

Who Typically Completes the Radon Disclosure Addendum

The addendum is used by multiple participants in a real estate transaction who need to document radon-related facts and decisions before closing.

  • Real estate agents — prepare and attach addendum to purchase contracts and advise clients on testing options and disclosure timing.
  • Sellers and property owners — state known test results, mitigation history, and any warranties or service agreements tied to mitigation systems.
  • Title companies and closing agents — confirm disclosure presence for the title file and note any post-closing obligations in closing statements.

Use the addendum whenever radon testing or mitigation is known or active; if testing is pending, note the timetable and who will pay for additional testing or mitigation.

Stepwise Completion Process for the Addendum

Follow these core steps to prepare, verify, and finalize the Radon Disclosure Addendum in a transaction.

  • 01
    Gather Evidence: Collect test reports, lab certifications, and mitigation invoices.
  • 02
    Populate Fields: Enter names, address, numeric test result, and dates accurately.
  • 03
    Review With Parties: Have seller, buyer, and agent confirm factual statements before signing.
  • 04
    Sign and Store: Obtain signatures, notarization if required, and retain a final copy.

Digital Workflow Overview for eSigning the Addendum

A typical eSignature workflow reduces friction and preserves an auditable record; the sequence below is optimized for remote execution.

  • Upload Document: Upload the completed addendum PDF or DOCX into the signing platform.
  • Place Fields: Add signature, date, and initial fields plus any conditional fields for mitigation details.
  • Send to Signers: Specify signer emails and role order or generate a secure signing link.
  • Capture Audit Trail: Platform records timestamps, IPs, and authentication method for each action.

Essential Elements of a Professional Radon Disclosure Addendum

A complete addendum balances clear factual disclosure with legal clarity so buyers and sellers understand the state of the property and any follow-up obligations.

Plain-Language Disclosure

Clearly state whether radon testing was performed, the measured level in pCi/L, and whether it exceeds EPA guidance levels so readers immediately grasp the health context and risks.

Test Source and Method

Identify the testing company or laboratory, test type (short-term, long-term), equipment used, and any chain-of-custody or lab certification details to support result validity.

Mitigation History

Describe any mitigation system installed, the installer, installation date, maintenance history, and any transferable warranties or service agreements.

Responsibility Allocation

State who will pay for re-testing or mitigation if results exceed agreed thresholds, including deadlines and procedures for completing work before or after closing.

Buyer Acknowledgement

Include a buyer signature block acknowledging receipt of results, whether testing was independent, and whether buyer accepts the disclosed condition.

Signatures and Dates

Provide signature lines for seller(s), buyer(s), and agent(s) with printed names and dates; specify notary or witness requirements if state law requires authentication.

Critical Data Elements to Include

Property: Full address
Seller: Full legal name
Buyer: Full legal name
Test Result: Numeric pCi/L
Test Date: MM/DD/YYYY
Signature: Signer name and date

Practical Tips for Accurate and Efficient Completion

Apply consistent, documented practices to minimize errors and speed closing.

Verify Test Credentials
Confirm the testing company or lab accreditation and include lab identifiers on the report so results are defensible in disputes or insurance claims.
Standardize Dates and Units
Use MM/DD/YYYY for dates and pCi/L for radon levels throughout the file to prevent interpretation errors during review or title underwriting.
Document Mitigation Clearly
Include installer name, installation date, and warranty terms; attach invoices and system diagrams to the addendum for future owners.
Maintain an Audit Trail
Preserve a timestamped eSignature audit trail or notarization journal entry and store signed PDFs (PDF/A preferred) in the transaction folder.

Common Errors to Avoid

  • Omitting the test date or lab name, making results unverifiable during later review.
  • Using vague mitigation descriptions that fail to identify installer or warranty terms.
  • Mismatched names between the addendum and deed or purchase agreement creating title inconsistencies.
  • Failing to notarize or witness when required by state law, risking enforceability challenges.

Liability and Risks from Incomplete or Incorrect Disclosures

Civil Liability: Potential buyer claims
Contract Risk: Rescission or indemnity exposure
Closing Delays: Title objections or escrow holds
Insurance Issues: Claim denials for undisclosed hazards
Regulatory Fines: State penalties where disclosure mandated
Reputation: Broker and agent liability

Digital Signing Considerations and File Format Support

When executing electronically, use a platform that supports common file formats and captures an auditable signature record.

  • File Formats: PDF, DOCX, PDF/A
  • Integrations: Salesforce | Microsoft 365 | NetSuite
  • Authentication: Email OTP, SMS code, or stronger KBA

Retain completed documents in a secure repository with access controls and export signed files to PDF/A for long-term archival.

Recommended Digital Workflow Settings for the Addendum

Configure signing workflows to match your closing sequence and recordkeeping requirements.

Field Configuration
Authentication Email with optional SMS OTP
Auto-Attach Attach lab report PDF to the addendum
Retention Export signed copy as PDF/A
Notifications CC title company and broker on final copy

eSignature Solution Pricing and Capability Snapshot

Comparing common eSignature vendors can help match platform capabilities to your volume, compliance, and integration needs.

signNow DocuSign Adobe Sign PandaDoc HelloSign
Starting Price $8/user/mo $15/user/mo $14/user/mo $19/user/mo $15/user/mo
Free Trial 7-day free trial, no credit card Varies by vendor Varies by vendor Varies by vendor Varies by vendor
Bulk Send Yes Varies Varies Varies Varies
Audit Trail Yes Yes Yes Yes Yes
HIPAA Compliant Yes Yes Yes Varies Varies

Real-World Examples of Using the Addendum

Two representative customer scenarios illustrate common uses and operational benefits of a documented radon disclosure.

Tim Martin — Martin Properties

Tim needed a reliable remote process to complete disclosures and closings

  • He used an eSignature workflow to capture signatures and notarization where required
  • The result reduced scheduling delays, produced a complete audit trail, and kept the closing on schedule while preserving compliance and security.

Brian Fitzgibbons — Optica Ventures LLC

Brian's team manages multiple investment properties and required standard addendums for each sale

  • They standardized a template with fields for test results and mitigation
  • Standardization reduced errors and made it easy to attach lab reports and support documents for underwriting and title review.

Frequently Asked Questions About the Radon Disclosure Addendum

Answers to common questions about completion, eSignature validity, notarization, and document retention for the Radon Disclosure Addendum.


Need help? Contact support

be ready to get more
Join over 28 million airSlate SignNow users
Sign Now
Company
Forms
Pricing
Resources
Knowledge base
Other Products
© 2026 airSlate Inc. All rights reserved.