Radon Testing & Mitigation in Evanston
Four in ten Evanston homes were built before 1940 — greystones, brick two-flats, courtyard buildings, and Victorians on century-old foundations. We test and fix Evanston basements with licensed installs sized to vintage construction.
The oldest housing stock on the North Shore
Evanston's median home dates to 1953, and 40.3% of the city's housing was built before 1940 — several times the pre-war share of neighboring postwar suburbs. This is the North Shore's densest concentration of greystones, brick two-flats and three-flats, courtyard apartment buildings, and 19th-century houses along Ridge Avenue, nearly all of it sitting on foundations poured or laid before radon was even a word. Illinois' requirement for radon-resistant new construction arrived in June 2013; these buildings predate it by seventy to a hundred-plus years.
Age matters because entry points multiply over a century: settling cracks in slabs and rubble or block walls, old floor drains, coal chute and utility penetrations, and sump pits cut in decades later. Meanwhile the county numbers stay stubborn — nearly 30% of Cook County homes tested by licensed professionals come back at or above the EPA's 4.0 pCi/L action level, against a county zone map that predicts "moderate." A 48-hour closed-house test is the only way to know what a specific Evanston basement does.
Two-flats, landlords, and who breathes the basement air
Evanston is unusual on this shore: only 32.5% of its housing is single-family detached, and 43.8% of households rent. A lot of Evanston's radon exposure happens in garden units and basement apartments of vintage two-flats and courtyard buildings — the lowest, most soil-coupled living spaces in the building. If you own rental property here, testing is cheap due diligence for the people living closest to the slab, and a tagged, verified mitigation system is the kind of documented fix that protects both tenants and owners. One system typically treats the whole soil footprint under a two-flat, not just one unit.
Evanston code has radon language of its own
Evanston adopted the 2021 International Residential Code with local amendments that specifically cover radon control, alongside gas piping and venting — so mitigation work here runs against code language written with radon in mind, not a silent code book. Permits go through the city's Building & Development Services at the Civic Center. And because so much of Evanston sits inside historic districts, exterior routing on a vintage facade sometimes deserves the discreet option: an interior chase to the attic instead of a pipe on the streetside wall. Licensed installers who work Evanston regularly plan for this; it's part of the conversation before anything is drilled, and installs still run the standard $800 to $2,500 range with a verification test at the end.
Buying a two-flat or a vintage single-family here? The 48-hour transaction test fits a standard Evanston inspection window, and a high result is a negotiation item, not a deal-breaker.
Garden unit, greystone, or two-flat — test what your building breathes.
Call (224) 362-4440