Selling your Chevy Chase home? There is one rule you cannot skip. Montgomery County requires a radon test for most single-family homes and townhouses before closing. It is simple to handle if you plan ahead, and it can save you from last‑minute delays. In this guide, you will learn what the law requires, when to test, how to share results, and what to do if levels are high. Let’s dive in.

What the radon rule requires

Montgomery County’s law says a single‑family home located in the County must be tested for radon before completing a sale. The test must be done within one year before settlement, and both parties must receive the results. The seller must either perform the test or allow the buyer to perform it. You can review the full text in Montgomery County Code § 40‑13C for exact definitions and exemptions.

Which homes are covered

This rule covers detached single‑family homes and attached single‑family homes like townhouses in Chevy Chase. It does not cover condo or co‑op units. The law applies countywide, but you should confirm the property’s exact municipality within Chevy Chase in case a town has its own procedures.

Timing and responsibility

Your radon test must be performed less than one year before the settlement date. Many sellers test before listing or right after a contract is signed to keep the timeline smooth. If the buyer prefers to test, you must allow it. Either way, make sure both you and the buyer receive the official results before closing.

Why it matters in Chevy Chase

Chevy Chase sits in an area the EPA maps as higher radon potential. Radon is a naturally occurring gas and a known health risk. The EPA recommends action at 4.0 pCi/L and advises considering mitigation between 2 and 4 pCi/L. That is why the County requires testing as part of home sales.

How to handle testing

Choose the test and who performs it

Use an approved device and follow standard testing protocols. Many real estate transactions use a professional short‑term test with a continuous monitor because results are quick and widely accepted. Montgomery County’s guidance on buying or building a home explains device approval and testing steps.

When to schedule the test

If you want a head start, test before you go to market so you can disclose results with your listing. If you prefer to wait, plan to test promptly after contract ratification. Leave room in your contract for a follow‑up test if the first result is elevated.

Share results and keep records

Provide the report to the buyer and retain copies for your file. Keep any chain‑of‑custody or calibration documentation from the test provider. The County rule requires both parties to receive the results before settlement.

If your result is elevated

For sales, the County law requires testing and disclosure, not automatic seller remediation. If a test is at or above 4.0 pCi/L, common options include installing a mitigation system before closing, offering a credit, or negotiating terms under your radon contingency. Landlords have different duties under the County’s rental law, including a duty to mitigate confirmed levels at or above 4.0 pCi/L.

Typical costs and timelines are manageable. A professional short‑term test often runs about 100 to 250 dollars locally. Installed mitigation systems commonly fall in the rough 800 to 2,500 dollar range, with many projects near 1,000 to 1,500 dollars depending on the home. Installers usually complete work quickly and then retest to confirm reduction.

Avoid delays with smart contracts

• Add a radon testing contingency with clear deadlines.
• Decide who orders and pays for the test, then put it in writing.
• Require delivery of results and outline how mitigation or credits will be handled.
• Allow time for a follow‑up test if the initial result is elevated.
• Remember the County requires the test to be performed within one year before settlement.

Quick seller checklist

• Confirm your property type and municipality within Chevy Chase to understand which rules apply.
• Order an approved radon test early and keep device documentation.
• Share the official test report with the buyer and keep copies for your records.
• If results are at or above 4.0 pCi/L, get bids from certified mitigators and decide whether to remediate or negotiate a credit.
• If you are renting the property, follow the County’s separate rental testing and mitigation rules.

Enforcement at a glance

The County enforces the real property article that includes the radon rule. Violations are treated as Class A civil violations and may carry civil penalties. Beyond fines, the bigger risk to a seller is delay, buyer concerns, and potential exposure under disclosure laws. Staying ahead of the requirement keeps your sale on track.

Ready to list in Chevy Chase with confidence? The Dana Rice Group pairs neighborhood expertise with a concierge process, including listing production, complimentary staging for qualifying homes, and steady transaction management that keeps details on schedule. If you want a smooth sale and clear guidance from prep to closing, connect with the Dana Rice Group.

FAQs

Do Chevy Chase home sales have a mandatory radon test?

• Yes. Montgomery County requires a radon test for most single‑family homes and townhouses, performed within one year before settlement, and both parties must receive the results.

Does the radon rule apply to condos or co‑ops in Chevy Chase?

• No. The sales rule excludes units in a condominium regime or cooperative housing corporation, although buyers may still choose to test for peace of mind.

Who pays for the radon test in a Chevy Chase sale?

• The law requires the seller to perform the test or allow the buyer to perform it, and the purchase contract typically sets who pays; confirm this in your offer terms.

If my radon level is 4.0 pCi/L or higher, do I have to fix it before selling?

• Not automatically. For sales, the County requires testing and disclosure; mitigation is usually negotiated through your radon contingency, while landlords have a duty to mitigate under the rental law.

How much do radon testing and mitigation cost near Chevy Chase?

• Professional short‑term tests often cost about 100 to 250 dollars, and typical mitigation systems range roughly from 800 to 2,500 dollars depending on the home and system design.

References and resources used in this article: Montgomery County Code § 40‑13C; Montgomery County DEP guidance for buyers; EPA radon zone and action level; Maryland’s radon program; Montgomery County rental radon rules; mitigation guidance and typical costs.

Links in this guide:

• Montgomery County Code § 40‑13C (sales rule): https://codelibrary.amlegal.com/codes/montgomerycounty/latest/montgomeryco_md/0-0-0-145064
• Montgomery County DEP guidance for buying or building: https://www.montgomerycountymd.gov/DEP/property-care/air/indoor-air/radon-buying-home.html
• EPA radon zones and action level: https://www.epa.gov/radon/epa-map-radon-zones-and-supplemental-information
• Montgomery County rental radon rules: https://www.montgomerycountymd.gov/DHCA/landlords/Radon.html
• Maryland radon program and kits: https://mde.maryland.gov/programs/Air/RadiologicalHealth/Pages/radon.aspx
• Typical mitigation costs and steps: https://sosradon.org/reducing-radon-in-your-home
• Typical professional testing cost reference: https://www.calamus-enterprises.com/ce-radon-testing/
• Enforcement overview, penalties: https://codelibrary.amlegal.com/codes/montgomerycounty/latest/montgomeryco_md/0-0-0-145081