Radon Mitigation Leads in MA: The Zone 1 Tell

TL;DR

• Massachusetts mandates no radon test and no radon permit, so there is no record to chase directly.
• New homes in Essex, Middlesex, and Worcester were built with a passive radon stack waiting for a fan.
• Three readable signals: Zone 1 new builds, basement-finish permits, and inspection-driven home sales.
• A permit is a signal about the homeowner and their house, not about the contractor who pulled it.

Massachusetts requires no radon test to sell an existing home and issues no radon permit, so most mitigation companies assume permit data has nothing for them. They are reading the wrong word. The building code already marks which new homes were built half-mitigated, and the basement-finish permit marks the moment radon turns into a living-space problem. Both are public record, and both reach you before the homeowner has called anyone.

The trade's usual playbook is to wait for a failed test to ring the phone, then bid against whatever the homeowner googled at midnight. That is reactive, and it is a price fight. The better play is to be the name a household already has when the radon question opens, and in Massachusetts that question opens at three predictable, recorded moments.

Why there is no radon permit to chase in Massachusetts

Start with what does not exist, because it explains why the data looks empty.

Massachusetts has no law requiring an existing home to be tested for radon, and no law requiring a seller to disclose radon to a buyer. A seller has to answer honestly if asked, but nobody has to test, and nobody has to share an old result. There is also no standalone radon permit. Adding a mitigation fan to an existing house is typically electrical work with a small footprint, not a tracked building event the way a deck or a service upgrade is. So a contractor who searches permit records for the word "radon" finds close to nothing and concludes the data is useless.

It is not useless. It is pointing at the wrong record.

The risk is real even if the paperwork is thin. Massachusetts public-health data estimates roughly 650,000 homes statewide sit above the EPA action level of 4 picocuries per liter, with about 34,000 over 20 pCi/L, and that about one in four Massachusetts homes has the potential to exceed the action level. That is a large, underserved market with no regulatory funnel pushing homeowners toward you. You have to read the funnel yourself, out of the records that do exist.

The Zone 1 rule: which new homes were built half-mitigated

Here is the fact almost no radon marketing mentions, and it is the core of the play.

Since January 2, 2015, the Massachusetts residential code has required a passive radon control system in every new one- and two-family dwelling and townhouse built in the three counties the code flags as high radon potential: Essex, Middlesex, and Worcester. The requirement lives in 780 CMR Appendix AF, and the three counties are named in Table AF101(1) as the state's Zone 1. The Board of Building Regulations and Standards approved the amendment in September 2014. There is no level test involved. The system goes in regardless of the radon reading at the site, because the whole point is to be ready.

What that system is matters. It is a sub-slab vent stack: perforated pipe under the slab, a sealed riser running up through the house and out the roof, and the slab penetrations sealed. The code describes its purpose plainly, to "prepare the dwelling for post-construction radon mitigation, if necessary." In other words, the expensive, disruptive part of a mitigation install, running the pipe, is already done. No testing is required when the home is finished, so the owner does not actually know their number.

That is the opening. A house built in those three counties in the last several years is a house with the stack already in the wall and no test on file. If the homeowner ever tests over 4 pCi/L, the fix is usually just adding an in-line fan and a monitor to the existing riser. Fast, clean, low-cost to deliver, and high-margin precisely because the hard work was pre-installed by code.

What the code requires	Where it applies	What it leaves you
Passive radon stack, no fan, no test	New 1–2 family + townhouses, Essex / Middlesex / Worcester (Zone 1)	A house pre-plumbed for mitigation, untested, owner unaware
Nothing	Existing homes, all 14 counties	A test only when a sale or a remodel forces it

The records a radon company can actually read

Stop hunting for a radon permit and read the three records that mark where radon work becomes likely. Each one puts a household one decision away from calling you.

Lead pool	The record you read	What it means	When to act
Built half-mitigated	New 1–2 family permit in Essex, Middlesex, or Worcester	A passive stack is in; one test and a fan finish the job	After occupancy, before the first winter test
New living space below grade	Basement-finish permit, any county	The lowest level becomes occupied; radon moves from abstract to urgent	Weeks 1–8, during the build
Changing hands	Home sale, listing, or pending deal	The buyer's inspection adds a radon test on a deal clock	At inspection and closing

The first pool is the Zone 1 new build, covered above. The volume is meaningful because Essex and Middlesex County carry some of the heaviest new-construction permit counts in the state, and every qualifying home in them carries a stack.

The second pool is the basement-finish permit, and it is statewide, not limited to Zone 1. The third is the home sale, where the test rides in on the home inspection the buyer is already paying for. Three records, three different homeowners, one product.

How to read a new-construction permit in a Zone 1 county

Treat a Zone 1 new-build permit the way an electrician treats a service-upgrade permit: as a precise marker of what was installed and what comes next.

A new single-family or two-family permit in Essex, Middlesex, or Worcester tells you, without your having to ask, that a passive radon system went into that house. You do not need to confirm it parcel by parcel, because the code required it and the building inspector signed off on it. What you do not know is the level, and neither does the owner, because no test was required. That unknown is your entire pitch.

The right moment is after the family has moved in and lived through a heating season, when a test will read at its truest. A passive stack often drops a home below the action level on its own, but not always, and the only way to know is to test. Position yourself as the company that tests the stack the builder left, reads the result, and adds the fan if the number calls for it. You are not selling a system. You are finishing one.

Why a basement-finish permit is the statewide trigger

The basement-finish permit is the cleanest radon signal in the whole state, and it works in all fourteen counties.

Radon enters at the lowest level of a house and concentrates there. As long as the basement is a dark storage space nobody occupies, the homeowner does not think about it. The day they pull a permit to finish it into a family room, a bedroom, or a home office, they are about to put people, and often a child's bedroom, into the highest-radon room in the building. That is the moment radon stops being a line item on an old inspection and becomes a reason to test.

It is also a budget moment. Someone finishing a basement has a contractor on site, a permit open, and money allocated to make the lower level livable. Adding a radon test, and a system if the result calls for one, is a small line on a project that is already happening. Reach the homeowner during the build, in roughly Weeks 1 to 8 after the permit, while the walls are still open and a stack can be run cleanly instead of retrofitted later. The finishing trades are working the same address for the same reason, which is why these signals cluster.

When to reach the homeowner, and what to say

Timing and message decide whether this reads as service or as spam.

For the Zone 1 new build, reach out after the first winter the family spends in the house. Massachusetts recommends testing between November 1 and March 31, when homes are closed and heating systems run and levels read highest, so a fall touch that offers a winter test lands at the natural moment. For the basement finish, work the build window. For a sale, move on the deal clock: a buyer who just tested over 4 pCi/L needs the fix before closing, and the real-estate agent tracking that listing is motivated to keep the deal alive.

Lead with the house, never with the record. The homeowner does not want to hear that you found their permit. They want to hear that you understand their specific situation: a stack already in the wall that has never been tested, a soon-to-be-finished basement that will be the lowest occupied room, a deal that hangs on a number. Name the real threshold, 4 pCi/L, and the simple path from test to fan. Keep it informational, not alarmist. You are not selling fear. You are selling the one thing a Massachusetts home never comes with by law: someone whose job is to check the air.

How permits.llc fits in

permits.llc turns Massachusetts permit records into a lead feed you can filter by county and permit type, which is exactly how a radon company reads the three pools at once. Filter Essex, Middlesex, and Worcester for new one- and two-family construction to find the homes built with a passive stack, and filter every county for basement-finish permits to find the new below-grade living space.

The free 2026 download holds every 2025 Massachusetts permit record, more than 167,000 of them, so you can map the Zone 1 new builds and basement finishes in your own towns before you spend a dollar. Paid daily alerts then push each new qualifying permit to you within 24 hours of filing, early enough to reach the homeowner before the first winter test or during the basement build, instead of months after someone else added the fan.

Start with the free download to see how many half-mitigated new homes and basement finishes are already on file near you, then switch on daily alerts so the next one reaches you while the radon question is still open.