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Radon testing

Radon Testing in Chantilly, VA

A continuous monitor on the lowest level that could be used regularly, read every hour for at least 48 hours. The written result comes the day we collect it.

4.9 rating, over 4,000 reviews NRSB-certified technicians Serving Fairfax County

Schedule a radon test Call (703) 450-6398

What our customers say

From our customer reviews.

They conducted the test right away and kept me informed every step of the way.

They arrived the day after I called, on time, set up the Radon test and left within 5 minutes.

Everything was handled so professionally, quickly and so easy to have our house tested for radon.

They found elevated radon in the home and numerous issues on the home inspection report which were remedied before I moved in.

Great service, very thorough inspection and highlighted items in a very approachable and organized manner.

How much does radon testing cost in Chantilly?

A radon test in Chantilly is $185, or $175 when it is added to a home inspection. That is the whole price: both visits, the monitor for the full 48 hours, and the written report with every hourly reading in it. The appointment covers one Chantilly residence at the confirmed address. A separate basement tenancy, accessory unit or second structure should be disclosed so authorization and pricing can be reviewed.

Day 1

Drop-off

We place the monitor

A technician places it on the lowest level that could be used regularly, following EPA placement limits and the intended use of the space, inside a two-hour arrival window. With a home inspection, placement happens during the inspection visit.

48 hours

The house stays closed

The monitor does the work

For a short-term real-estate test, EPA guidance calls for closed-building conditions for at least 12 hours before the test and throughout the measurement. Windows stay closed, exterior doors open only for normal entry and exit, and the monitor logs hourly readings that help document the test conditions during the minimum 48-hour measurement.

Day 3

Pick-up and report

We collect it, read it, and write it up

A technician picks the monitor up in another two-hour window and pulls the full record on the spot. The written report reaches you the same day.

NRSB-certified technicians. Our own team, certified by the National Radon Safety Board, not a subcontractor.

EPA testing guidance. Placement, closed-house conditions and the 48-hour minimum follow it, and your average is read against the EPA action level of 4.0 pCi/L.

Continuous monitors. Airthings Corentium Pro instruments, logging every hour for the whole test.

Appointment times are requests until our team confirms them. What the number means, how to prepare the property and the eight questions everyone asks are on the radon testing page; this page is about Chantilly.

Chantilly radon testing: confirm Fairfax or Loudoun County

A Chantilly mailing address can be in Fairfax or Loudoun County, so confirm the property's jurisdiction before using a county radon map. Fairfax is EPA Zone 1. The older map lists Loudoun as Zone 2, while the Virginia Department of Health says newer results support a high-risk designation there. None of these area labels measures the indoor level of a Chantilly residence.

Radon testing in Chantilly should start with the full street address and the actual dwelling. Fairfax County planning records describe detached and townhouse communities such as Greenbriar and Brookfield, while Loudoun County facilities use Chantilly mailing addresses near South Riding. Tell the technician which lower rooms could be used regularly, whether a walkout door or separate unit changes access, and who can admit the team twice.

Local background: Fairfax County Stringfellow planning text for Greenbriar and Brookfield, Virginia Department of Health radon map information, EPA Map of Radon Zones limitations, Loudoun County Chantilly-address facility.

The James S. McDonnell Space Hangar at the Udvar-Hazy Center in Chantilly

South Riding and Fairfax neighborhoods

Verify county rather than relying on the Chantilly mailing name. The correct jurisdiction keeps the map context accurate.

Walkout and lower rooms

Describe any lower living area and exterior door so the technician can assess placement in the booked residence.

Vacant-home access

Confirm utilities, climate operation, lockbox or alarm steps and an authorized contact for both visits.

Where we test in Chantilly, and what to tell us

South Riding, Franklin Farm, Armfield Farms
South Riding has Loudoun County addresses with a Chantilly mailing name; Franklin Farm and Armfield Farms are Fairfax references. Verify the property county.
Poplar Tree Estates
For Poplar Tree Estates, explain how a lower walkout room is used now or planned to be used later.
Pleasant Valley
In Pleasant Valley, identify who controls entry when the residence is vacant or tenant-occupied and coordinate both visits.

We only perform testing, not mitigation.

We do not install radon systems, so we have nothing to gain from your number. If the result is at or above the EPA action level of 4.0 pCi/L, you choose who fixes it. Once the system is in, we can test again and tell you what it reads.

Before you book in Virginia

Virginia's residential disclosure statute directs the seller's disclosure statement to say that the owner makes no representation about whether the property is in an EPA Zone 1 or Zone 2 locality. It directs buyers to use due diligence, including reviewing EPA, Virginia Department of Health and NRSB information and ordering a radon inspection before settlement as the contract allows.

Va. Code section 55.1-703. Current as of September 2026. General information, not legal advice.

Radon testing near Chantilly

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Radon testing in Chantilly, answered straight

Why should a Chantilly customer verify the county first?

Chantilly mailing addresses can fall on different sides of the Fairfax and Loudoun boundary. The confirmed county keeps the service record and cited local planning context tied to the correct property.

Does the Greenbriar and Brookfield source describe South Riding?

No. The cited Fairfax planning text is limited to Greenbriar and Brookfield, while South Riding is a Loudoun County community. It should not be generalized across the mailing area.

What preparation matters for a Chantilly walkout lower level?

Follow the closed-building directions, avoid prolonged use of the exterior door near the test area and finish contractor activity first. Explain the room’s regular or planned use at setup.

What should a Chantilly buyer send about the contingency?

Provide the expiration date, access windows and requested report deadline when scheduling. The office can then determine whether two visits and the 48-hour minimum fit the available period.

Book a radon test in Chantilly

Book online or call (703) 450-6398.

Schedule a radon test Request a price

NextDay Inspect
46179 Westlake Dr, Ste 200, Sterling, VA 20165
(703) 450-6398

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