Assess First, Design Once
Radon levels vary by neighborhood and building construction. Even if a region isn’t flagged as high risk, test before design—and again after air-sealing and insulation—because tighter envelopes can change pressure dynamics. If readings exceed action levels, plan a mitigation pathway that won’t disrupt your finished space.
Sub-Slab Depressurization, the Right Way
A standard solution is sub-slab depressurization via one or more suction points, a sealed slab (caulked cracks, gasketed penetrations), and a continuously running in-line fan vented above the roofline. During the remodel, pre-install a passive stack (PVC from slab to attic) and an electrical junction near the future fan to avoid opening walls later. Seal sump lids with viewports and gaskets.
Coordinate with IAQ & Energy
Pair mitigation with balanced ERV ventilation and a ducted dehumidifier to stabilize indoor pressure and humidity. Use MERV-13 filtration on air handlers and maintain dedicated makeup air if you have vented dryers or combustion appliances (or convert to sealed-combustion/heat-pump alternatives).
Materials & Detailing
Choose low-VOC finishes and maintain continuous sub-slab vapor barriers under flooring. Provide service access to radon gauges and fan disconnects, and document the routing in your as-builts for future inspections.
For an integrated approach that blends testing, mitigation, and fresh-air design, review our NYC basement ventilation and air quality.