ANSI/AARST CC-1000 Radon Design Requirements for New Construction

The ANSI/AARST CC-1000 radon design requirements for new construction are the prescriptive minimum rules a soil gas control system has to meet before a plan reviewer will approve it: a continuous gas barrier under the building, a gas-permeable collection layer, suction points that can depressurize the soil, and vent stacks that discharge cleanly above the roof. CC-1000-2018 applies to new construction of buildings intended for human occupancy other than one- and two-family dwellings, which puts multifamily, school, commercial, and mixed-use projects in scope. This page walks through what the standard requires, the specific design elements it names, and how those requirements become a stamped package your permit set can carry.

CC-1000-2018 is a consensus standard, not a guideline a builder can interpret loosely. The EPA recognizes the ANSI/AARST consensus standards as the radon standards of practice, so when a lender, a plans examiner, or an environmental reviewer asks how radon is handled, the answer they expect is a design built to this standard. A package that gestures at radon without keying to CC-1000 gets sent back.

CC-1000-2018 sets the minimum requirements for soil gas control in the new construction of buildings, and its scope is every building intended for human occupancy except one- and two-family dwellings. In practice that means:

• Multifamily residential: apartments, condominiums, and congregate housing.
• Educational occupancies: new schools and child-care facilities.
• Commercial and mixed-use buildings where people work or gather.

The distinction matters because single-family homes follow a different, prescriptive residential path, while every larger building has to be engineered to CC-1000 from the first foundation drawing. The standard treats the whole footprint as one system, so a four-building apartment site is four coordinated designs, not one detail copied across the set. A plans examiner checks the package against the standard line by line, so the design has to be drawn to it from the start rather than retrofitted to pass review.

The standard is prescriptive, which means it names the components a compliant design has to include rather than leaving them to judgment. A CC-1000 design package specifies:

• A continuous soil gas barrier: an unbroken membrane between the soil and the occupied space, sealed at every penetration, footing, and construction joint.
• A gas-permeable collection layer beneath the slab that lets soil gas move freely toward the suction points.
• Suction point locations and spacing sized to draw a pressure field across the full sub-slab area.
• Vent piping routed from each suction point up through conditioned space to a roof discharge.
• Provisions for a fan, plus the pressure-field and HVAC evaluations that confirm the system performs as drawn.

Two requirements drive most of the work. The barrier has to be continuous, because a single unsealed joint lets soil gas bypass the whole system. And the collection layer plus vent piping has to be capable of depressurizing the soil under that barrier, either by natural draft or with a fan. The standard also calls for evaluating how the building's mechanical systems interact with that pressure field, because an HVAC layout that puts the slab under negative pressure can pull soil gas in faster than the vent system clears it. Everything else on the sheets exists to serve those functions.

CC-1000 does not leave exhaust location to the installer. The standard requires the point of exhaust to be located either not less than 4 feet above operable openings in the structure, or not less than 10 feet horizontally to the side of those openings. The intent is to keep vented soil gas from being drawn back into the building through a window, door, or air intake.

For a multifamily or commercial building, that rule shapes the stack routing on every sheet. Vent stacks have to clear the roofline at a point that holds the separation from operable openings, which on a large building crowded with windows and rooftop equipment is a real layout problem rather than a default. Get it wrong and you have a system that recirculates the gas it was built to remove, and a reviewer who rejects the set.

A CC-1000 system is designed passive first and built so it can go active without rework. A passive system uses the stack effect, warm air rising in the vent pipes, to pull soil gas up and out with no fan and no power draw. When the building is large, the soil is tight, or post-construction testing shows the passive draw falls short, an inline fan is added to each stack. Because the design already locates the fan position, the electrical rough-in, and the labeling, that conversion is a field change, not a redesign.

The 2023 revision to the standard tightened the construction-stage inspections, so a current design has to anticipate what an inspector verifies before, during, and after the slab is poured. Those checkpoints belong on the drawings from the start, because a barrier detail that cannot be inspected at the right stage is a barrier detail that fails verification, and a failed verification stalls the pour.

Meeting these requirements on paper is the deliverable. A CC-1000 design package is drawn from your building, so it starts with your architectural plans: send a vector PDF set exported from CAD or Revit, and the design lays out the collection and vent system across the footprint, specifies the barrier and sealing details, routes and locates the stacks to the exhaust rule, and references the governing standard throughout. A certified radon professional reviews and signs it, so the credential the compliance chain expects is built into the package rather than bolted on after a rejection.

If you are scoping a new multifamily, school, or commercial building, the new-construction radon code reference lays out which standard governs your project, and you can request a quote with your plans to get a fixed price for a stamped CC-1000-2018 package before any work begins.