{"id":1985,"date":"2026-02-02T20:32:16","date_gmt":"2026-02-03T02:32:16","guid":{"rendered":"https:\/\/radonresources.com\/blog\/?p=1985"},"modified":"2026-03-17T14:32:31","modified_gmt":"2026-03-17T19:32:31","slug":"radon-in-chicago-why-ground-contact-units-matter","status":"publish","type":"post","link":"https:\/\/radonresources.com\/blog\/radon-in-chicago-why-ground-contact-units-matter\/","title":{"rendered":"Radon in Chicago: Why Ground-Contact Units Matter"},"content":{"rendered":"<h1>Radon in Chicago and the Surrounding Suburbs: Why Ground-Contact Units Matter Most<\/h1>\n<p>Radon in Chicago is easy to underestimate because the region feels so built-up and vertical\u2014courtyard buildings, multi-flats, condos, and tight lot lines. But radon doesn\u2019t care what\u2019s happening at street level. It starts below the building, then follows the paths that connect soil to indoor air.<\/p>\n<p>That\u2019s what makes the Chicago metro\u2019s housing mix especially relevant. We don\u2019t just have \u201chomes\u201d\u2014we have a huge number of <strong>ground-contact living spaces<\/strong>: finished basements used as family rooms or home offices, garden units that function as full apartments, and split-level lower floors that sit partly below grade. In a high-density area, the same address can include units with very different radon exposure simply because some spaces touch the ground and others don\u2019t.<\/p>\n<p>The big takeaway is simple: if your living space touches the ground\u2014garden unit, basement, lower level, slab-on-grade first floor\u2014it deserves priority testing, whether you\u2019re in the city or in suburbs like <strong>Oak Park, Cicero, Evanston, Skokie, Berwyn, Naperville, Schaumburg, or Downers Grove<\/strong>.<\/p>\n<hr \/>\n<h2>Why radon affects both Chicago and nearby suburbs<\/h2>\n<p>Radon comes from the ground and can build up indoors, especially in lower levels. In the Chicago area, that means the risk story isn\u2019t \u201ccity vs. suburb\u201d\u2014it\u2019s <strong>ground-contact vs. not<\/strong>.<\/p>\n<h3>It\u2019s about geology and soil gas\u2014not \u201ccity vs. country\u201d<\/h3>\n<p>Across Chicago and the surrounding communities, radon potential comes down to what\u2019s under the structure and how the building interacts with the ground. Practical factors that influence whether radon moves inside include:<\/p>\n<ul>\n<li>Soil and rock conditions (and how soil gas moves)<\/li>\n<li>Moisture and drainage patterns around the foundation<\/li>\n<li>Foundation type and ordinary gaps\/openings<\/li>\n<li>Pressure differences that pull soil gas inward (stack effect, HVAC, exhaust fans)<\/li>\n<\/ul>\n<p>That\u2019s why variability can be <strong>house-to-house and block-to-block<\/strong>. Two similar-looking homes in <strong>Berwyn<\/strong> might test differently. Two units in the same courtyard building in <strong>Evanston<\/strong> can test differently too\u2014especially if one is a garden unit and one is on an upper floor.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-1997\" src=\"https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_666950110_XL-1024x412.jpg\" alt=\"\" width=\"625\" height=\"251\" srcset=\"https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_666950110_XL-1024x412.jpg 1024w, https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_666950110_XL-300x121.jpg 300w, https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_666950110_XL-768x309.jpg 768w, https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_666950110_XL-624x251.jpg 624w\" sizes=\"auto, (max-width: 625px) 100vw, 625px\" \/><\/p>\n<hr \/>\n<h2>Radon Levels in the Greater Chicago Area and Surrounding Communities<\/h2>\n<h3>Variability is the headline<\/h3>\n<p>When people search \u201cradon in suburbs near Chicago\u201d or \u201cCook County radon,\u201d they usually want a quick answer. What you get in reality is a local picture: trends can help with awareness, but your result depends heavily on the specific unit and whether it\u2019s in contact with the ground.<\/p>\n<p>That\u2019s especially true for garden units and basements in dense neighborhoods\u2014where one building can contain both the highest-priority spaces (ground-contact) and the lowest-priority spaces (upper floors). This holds across Chicago and nearby communities like <strong>Oak Park, Cicero, Evanston, Skokie, and Berwyn<\/strong>, and it also applies in farther suburbs like <strong>Schaumburg, Downers Grove, and Naperville<\/strong>.<\/p>\n<p>If you want to explore community-level context, start with a local directory and statewide overview:<\/p>\n<ul>\n<li><a href=\"\/illinois\/chicago-metro\/\">Chicago, IL<\/a><\/li>\n<li><a href=\"https:\/\/radonresources.com\/illinois\/\">Illinois Radon Mitigation<\/a><\/li>\n<\/ul>\n<div>\n<div>RadonResources.com user-submitted radon tests in the Chicago, IL area show a pattern residents should take seriously: across 32 submissions from the metro and nearby communities, the average reported level is <strong>7.1 pCi\/L<\/strong> (median 7.0 pCi\/L).<\/div>\n<div><\/div>\n<div>Specifically, <strong>94% of submissions<\/strong> are at or above 4.0 pCi\/L (the EPA action guideline), and 12% are 10 pCi\/L or higher. The highest submitted reading in this dataset for the metro is 20 pCi\/L.<\/div>\n<div><\/div>\n<div>Because radon can vary dramatically from one house to the next\u2014even on the same street\u2014the takeaway isn\u2019t to guess; it\u2019s to test your specific home, especially if you have a basement, garden unit, crawlspace, or spend a lot of time on the lowest level.<\/div>\n<\/div>\n<div class=\"rr-data-table-wrap\">\n<table class=\"rr-data-table\">\n<thead>\n<tr>\n<th>City<\/th>\n<th>Submissions<\/th>\n<th>Avg pCi\/L<\/th>\n<th>Median pCi\/L<\/th>\n<th>% \u2265 4.0<\/th>\n<th>Max<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><a href=\"\/illinois\/arlington-heights\/\">Arlington Heights, IL<\/a><\/td>\n<td style=\"text-align: right;\">5<\/td>\n<td style=\"text-align: right;\">5.6<\/td>\n<td style=\"text-align: right;\">5.0<\/td>\n<td style=\"text-align: right;\">80%<\/td>\n<td style=\"text-align: right;\">8<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/illinois\/aurora\/\">Aurora, IL<\/a><\/td>\n<td style=\"text-align: right;\">4<\/td>\n<td style=\"text-align: right;\">6.8<\/td>\n<td style=\"text-align: right;\">7.0<\/td>\n<td style=\"text-align: right;\">100%<\/td>\n<td style=\"text-align: right;\">8<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/radonresources.com\/illinois\/naperville\/\">Naperville, IL<\/a><\/td>\n<td style=\"text-align: right;\">4<\/td>\n<td style=\"text-align: right;\">6.2<\/td>\n<td style=\"text-align: right;\">5.0<\/td>\n<td style=\"text-align: right;\">100%<\/td>\n<td style=\"text-align: right;\">11<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/illinois\/chicago\/\">Chicago, IL<\/a><\/td>\n<td style=\"text-align: right;\">3<\/td>\n<td style=\"text-align: right;\">11.0<\/td>\n<td style=\"text-align: right;\">11.0<\/td>\n<td style=\"text-align: right;\">67%<\/td>\n<td style=\"text-align: right;\">20<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/illinois\/tinley-park\/\">Tinley Park, IL<\/a><\/td>\n<td style=\"text-align: right;\">3<\/td>\n<td style=\"text-align: right;\">7.7<\/td>\n<td style=\"text-align: right;\">8.0<\/td>\n<td style=\"text-align: right;\">100%<\/td>\n<td style=\"text-align: right;\">8<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/illinois\/joliet\/\">Joliet, IL<\/a><\/td>\n<td style=\"text-align: right;\">3<\/td>\n<td style=\"text-align: right;\">6.7<\/td>\n<td style=\"text-align: right;\">7.0<\/td>\n<td style=\"text-align: right;\">100%<\/td>\n<td style=\"text-align: right;\">8<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/illinois\/schaumburg\/\">Schaumburg, IL<\/a><\/td>\n<td style=\"text-align: right;\">3<\/td>\n<td style=\"text-align: right;\">4.3<\/td>\n<td style=\"text-align: right;\">4.0<\/td>\n<td style=\"text-align: right;\">100%<\/td>\n<td style=\"text-align: right;\">5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div><\/div>\n<div><\/div>\n<h3>How to interpret aggregated or user-submitted data (and its limits)<\/h3>\n<p>Aggregated \u201ctesting databases\u201d or user-submitted maps can be useful for spotting patterns, but they\u2019re easy to misread if you don\u2019t account for unit type and building layout:<\/p>\n<ul>\n<li><strong>Sampling bias:<\/strong> People often test because they suspect an issue (or during a sale), not randomly.<\/li>\n<li><strong>Unit type matters:<\/strong> A third-floor condo result doesn\u2019t represent a garden unit in the same building.<\/li>\n<li><strong>Season matters:<\/strong> Winter \u201cclosed-house\u201d conditions can produce higher readings than mild-weather testing.<\/li>\n<li><strong>Mitigation history:<\/strong> Some homes are already mitigated; results may reflect post-mitigation conditions.<\/li>\n<li><strong>Measurement type:<\/strong> Short-term vs long-term tests can tell different stories.<\/li>\n<\/ul>\n<p>Use community trends as a prompt\u2014not a conclusion. For neighborhood-level browsing and comparisons, see:<\/p>\n<ul>\n<li><a href=\"https:\/\/radonresources.com\/user-submitted-radon-levels\/\">User Submitted Radon Levels<\/a><\/li>\n<\/ul>\n<hr \/>\n<h2>Foundation styles common across the metro<\/h2>\n<p>Chicago-area buildings span multiple eras and construction styles, and each one creates its own set of \u201cnormal\u201d pathways where soil gas can move. You don\u2019t need to diagnose your foundation like an engineer\u2014but understanding the basics helps you test in the right spot and interpret results without overthinking them.<\/p>\n<h3>Vintage Chicago housing (city + inner-ring suburbs)<\/h3>\n<p>Common building types across Chicago, <strong>Cicero<\/strong>, <strong>Berwyn<\/strong>, <strong>Oak Park<\/strong>, and parts of <strong>Evanston\/Skokie<\/strong> include:<\/p>\n<ul>\n<li><strong>Bungalows<\/strong> (often with basements that get finished over time)<\/li>\n<li><strong>2-flats and 3-flats<\/strong> (basement laundry\/mechanical spaces; sometimes garden units)<\/li>\n<li><strong>Courtyard buildings<\/strong> (more ground-contact units; shared utility runs)<\/li>\n<li><strong>Older brick and masonry foundations<\/strong> (more joints, patches, and penetrations)<\/li>\n<\/ul>\n<p>In these buildings, basements aren\u2019t just \u201cutility space.\u201d They\u2019re where people put a second TV room, a workout area, a guest bedroom, or a desk when the main floors are tight. Garden units, meanwhile, are a common way renters and owners add livable square footage\u2014exactly why ground-contact testing matters.<\/p>\n<h3>Suburban single-family mix<\/h3>\n<p>In places like <strong>Naperville<\/strong>, <strong>Schaumburg<\/strong>, and <strong>Downers Grove<\/strong> you\u2019ll see:<\/p>\n<ul>\n<li><strong>Brick Georgian colonials<\/strong> (often full basements)<\/li>\n<li><strong>Split-levels and raised ranches<\/strong> (lower levels partly below grade)<\/li>\n<li><strong>Ranches<\/strong> (basement or slab-on-grade depending on era)<\/li>\n<li><strong>Newer slab-on-grade homes<\/strong> (radon can still enter through slabs and penetrations)<\/li>\n<\/ul>\n<p>Even when a home feels \u201cnewer\u201d or more open-plan, radon pathways don\u2019t disappear\u2014they just change shape. Slabs, utility penetrations, and sump areas still connect indoor air to the ground.<\/p>\n<h3>Common radon entry points (what to look for)<\/h3>\n<p>Radon typically enters where the building meets the ground, including:<\/p>\n<ul>\n<li>Sump pits (especially uncovered or loosely covered)<\/li>\n<li>Floor cracks and wall-floor joints (cove joints)<\/li>\n<li>Utility penetrations (gas line, water line, electrical)<\/li>\n<li>Drain tiles and perimeter drainage systems<\/li>\n<li>Crawlspaces (vents and soil exposure)<\/li>\n<li>Slab joints and control cuts<\/li>\n<li>Around floor drains, ejector pits, and cleanouts<\/li>\n<\/ul>\n<p>You don\u2019t need to \u201cfind the crack\u201d to justify testing. Many of these are ordinary features in Chicago-area foundations\u2014especially in older properties throughout <strong>Skokie<\/strong>, <strong>Oak Park<\/strong>, and <strong>Berwyn<\/strong>, and in basement-heavy subdivisions in <strong>Downers Grove<\/strong> and <strong>Naperville<\/strong>.<\/p>\n<hr \/>\n<h2>Garden units, basements, and split-level homes<\/h2>\n<p>If you remember one section, make it this one: <strong>ground-contact units are the highest priority for radon testing<\/strong> because they sit closest to the source and usually have the most direct entry routes.<\/p>\n<p>In the Chicago metro, \u201cground-contact\u201d isn\u2019t a niche scenario\u2014it\u2019s a normal part of how people live. A garden unit can be someone\u2019s primary apartment. A basement can be a teen hangout, an in-law setup, a guest room, or a work-from-home space. Those are exactly the rooms where you want clarity.<\/p>\n<h3>Garden unit radon (Chicago classic)<\/h3>\n<p>Garden units are common across Chicago and inner suburbs like <strong>Evanston<\/strong>, <strong>Oak Park<\/strong>, <strong>Cicero<\/strong>, and <strong>Berwyn<\/strong>. They often have:<\/p>\n<ul>\n<li>Below-grade walls<\/li>\n<li>Shared mechanical spaces nearby<\/li>\n<li>Sump pits and drain tiles in older buildings<\/li>\n<li>Limited ventilation compared to upper floors<\/li>\n<\/ul>\n<p>If you rent a garden unit, it\u2019s reasonable to ask the owner or property manager about prior <a href=\"https:\/\/radonresources.com\/radon-testing\/\">Radon Testing<\/a>\u2014and to request testing if it hasn\u2019t been done. If you own a building with a garden level, prioritizing that unit protects the people most likely to have higher exposure.<\/p>\n<h3>Basements: finished or unfinished, it still matters<\/h3>\n<p>A finished basement family room, home office, or bedroom is a living space\u2014so it should be tested like any other. And even if the basement is unfinished, it can still influence air upstairs through stairwells, ductwork, and ordinary air movement.<\/p>\n<p>Basements worth prioritizing include those with:<\/p>\n<ul>\n<li>Sumps or ejector pits<\/li>\n<li>Recent \u201ctightening\u201d upgrades (new windows, insulation, air sealing)<\/li>\n<li>Persistent dampness (not proof of radon, but commonly overlaps with soil-gas movement)<\/li>\n<\/ul>\n<p>This comes up constantly in older homes from the city to <strong>Skokie<\/strong>, where basements were originally utility-forward and later converted into comfortable daily-use spaces without anyone revisiting indoor air questions.<\/p>\n<h3>Split-level and raised ranch homes (suburb favorite)<\/h3>\n<p>Split-levels in places like <a href=\"\/illinois\/downers-grove\/\"><strong>Downers Grove<\/strong><\/a>, <strong>Schaumburg<\/strong>, and <strong>Naperville<\/strong> often have a lower level that\u2019s partly below grade. People sometimes assume \u201cit\u2019s not a basement,\u201d so radon won\u2019t apply. In practice, that lower level can behave like a basement because it shares walls or a floor with soil.<\/p>\n<p><strong>Rule of thumb:<\/strong> If the floor is on or below grade\u2014or the room shares walls with soil\u2014test it.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-1996\" src=\"https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_643404336_XL-1024x575.jpg\" alt=\"\" width=\"625\" height=\"351\" srcset=\"https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_643404336_XL-1024x575.jpg 1024w, https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_643404336_XL-300x169.jpg 300w, https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_643404336_XL-768x432.jpg 768w, https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2026\/02\/Depositphotos_643404336_XL-624x351.jpg 624w\" sizes=\"auto, (max-width: 625px) 100vw, 625px\" \/><\/p>\n<hr \/>\n<h2>Testing guidance for dense housing areas<\/h2>\n<p>Dense housing changes the logistics. It doesn\u2019t change the principle: <strong>test the spaces that touch the ground first<\/strong>, because that\u2019s where radon entry is most likely and where elevated results matter most for day-to-day exposure.<\/p>\n<h3>Where to place a test (and why placement matters)<\/h3>\n<p>In multi-unit buildings and compact neighborhoods, placement is the difference between a useful result and a confusing one.<\/p>\n<p><strong>Test the lowest lived-in level<\/strong>:<\/p>\n<ul>\n<li>Garden unit living area\/bedroom<\/li>\n<li>Basement family room or basement bedroom<\/li>\n<li>Split-level lower family room<\/li>\n<li>First-floor slab-on-grade spaces<\/li>\n<\/ul>\n<p>Avoid placing a test:<\/p>\n<ul>\n<li>In kitchens, bathrooms, or laundry rooms (humidity and airflow swings)<\/li>\n<li>Right next to exterior doors\/windows<\/li>\n<li>Directly in front of supply vents or fans<\/li>\n<li>In a crawlspace (unless it\u2019s actually used as living space\u2014rare)<\/li>\n<\/ul>\n<p>If you\u2019re in a Chicago courtyard building\u2014or managing units in <strong>Evanston<\/strong> or <strong>Oak Park<\/strong>\u2014don\u2019t let convenience push the test into a hallway or utility area that nobody actually lives in. You want the result to represent real exposure in the unit.<\/p>\n<h3>Short-term vs long-term: what to choose<\/h3>\n<ul>\n<li><strong>Short-term tests (2\u20137 days):<\/strong> Useful for quick screening or real estate timelines.<\/li>\n<li><strong>Long-term tests (90+ days):<\/strong> Better picture of typical exposure over time.<\/li>\n<\/ul>\n<p>Chicago winters often create \u201cclosed-house\u201d conditions naturally, which can be helpful for screening because buildings are sealed up. But any season can work\u2014what matters most is following the test instructions and selecting the right level.<\/p>\n<h3>Multi-unit buildings: test smart<\/h3>\n<p>For condo associations\/HOAs and landlords, the most practical approach is usually:<\/p>\n<ul>\n<li>Start with <strong>ground-contact units<\/strong><\/li>\n<li>Include units next to <strong>mechanical rooms<\/strong> or <strong>sump locations<\/strong><\/li>\n<li>Consider testing a sample of upper units for comparison, especially if there are open chases<\/li>\n<\/ul>\n<p>If you manage multiple buildings in <strong>Cicero<\/strong> and <strong>Berwyn<\/strong>, or you oversee properties spread from Chicago out to <strong>Skokie<\/strong>, standardizing your <a href=\"https:\/\/radonresources.com\/radon-testing\/\">Radon Testing<\/a> protocol helps you make consistent decisions building-to-building\u2014especially when garden units and finished basements are part of the rental inventory.<\/p>\n<hr \/>\n<h2>Real estate considerations<\/h2>\n<p>This is educational information, not legal advice\u2014but these are common, practical realities in Chicago-area transactions, where basements and garden units regularly show up as \u201cbonus space\u201d during tours.<\/p>\n<h3>Buyers: build testing into your inspection plan<\/h3>\n<p>If you\u2019re buying a bungalow in Chicago, a Georgian in <strong>Oak Park<\/strong>, or a split-level in <strong>Naperville<\/strong>, radon testing is a straightforward add-on during the inspection window\u2014especially when the space you\u2019ll actually use most is on the lowest level.<\/p>\n<p>Tips:<\/p>\n<ul>\n<li>Ask for a radon test on the <strong>lowest lived-in level<\/strong><\/li>\n<li>If there\u2019s a garden unit (legal or \u201cin-law\u201d), test that space specifically<\/li>\n<li>If the home has a mitigation system already, ask for documentation and consider a follow-up test to confirm performance<\/li>\n<\/ul>\n<h3>Sellers: testing early reduces surprises<\/h3>\n<p>A pre-listing test can prevent last-minute negotiations\u2014particularly in homes where the basement is staged as a TV room, guest suite, or office (common across the city and suburbs like <strong>Downers Grove<\/strong> and <strong>Schaumburg<\/strong>).<\/p>\n<h3>Condo buyers and HOAs<\/h3>\n<p>Condo situations vary widely:<\/p>\n<ul>\n<li>A 3rd-floor unit may have low risk, while the garden unit below may not.<\/li>\n<li>Mitigation may involve <strong>shared spaces<\/strong>, piping routes, or HOA approval.<\/li>\n<\/ul>\n<p>If you\u2019re buying a ground-contact condo in <strong>Evanston<\/strong> or <strong>Skokie<\/strong>, ask:<\/p>\n<ul>\n<li>Has the building tested ground-contact units?<\/li>\n<li>Any history of mitigation systems?<\/li>\n<li>Who is responsible for mitigation if needed (unit owner vs association)?<\/li>\n<\/ul>\n<h3>Renters: how to approach the conversation<\/h3>\n<p>If you rent a garden unit in Chicago or <strong>Berwyn<\/strong>, you can politely request:<\/p>\n<ul>\n<li>Prior radon testing results (if any)<\/li>\n<li>Permission for testing (many landlords will agree)<\/li>\n<li>A plan to address elevated results if found<\/li>\n<\/ul>\n<p>Keeping the request tied to the unit\u2019s ground-contact nature (rather than general fear) usually makes the conversation more straightforward: you\u2019re asking to test the space with the most direct connection to the soil, not making assumptions about the whole building.<\/p>\n<hr \/>\n<h2>Mitigation expectations<\/h2>\n<p>If testing shows elevated radon, mitigation is usually very doable\u2014especially in the types of basements and slab foundations common across Chicago and nearby suburbs. The practical goal is to address the ground-contact pathway, not to chase every tiny crack.<\/p>\n<h3>The most common approach: sub-slab depressurization<\/h3>\n<p>A standard system often includes:<\/p>\n<ul>\n<li>A pipe routed from under the slab to above the roofline<\/li>\n<li>A quiet, continuous fan that creates suction under the foundation<\/li>\n<li>Sealing of obvious openings as <strong>support<\/strong>, not the primary fix<\/li>\n<li>Attention to <strong>sump pit covers<\/strong> (tight-fitting, sealed lids are common)<\/li>\n<\/ul>\n<p>For more detail on methods and system components, see:<\/p>\n<ul>\n<li><a href=\"\/illinois\/\">Radon Mitigation in Illinois<\/a><\/li>\n<\/ul>\n<h3>How long it takes<\/h3>\n<p>In many single-family homes, installation is often completed in <strong>one day<\/strong>, though scheduling, electrical work, and routing complexity can add time.<\/p>\n<h3>Costs vary\u2014avoid assumptions<\/h3>\n<p>Pricing depends on:<\/p>\n<ul>\n<li>Foundation style (full basement vs slab vs crawlspace)<\/li>\n<li>Sump\/drain tile layout<\/li>\n<li>Pipe routing in finished spaces<\/li>\n<li>Electrical access and exterior placement<\/li>\n<li>Multi-unit complexity<\/li>\n<\/ul>\n<p>That variability shows up everywhere\u2014from older brick homes in <strong>Oak Park<\/strong> to split-levels in <strong>Schaumburg<\/strong>\u2014so it\u2019s more useful to compare proposed approaches than to chase a single \u201caverage.\u201d<\/p>\n<h3>Multi-unit buildings need coordination<\/h3>\n<p>For condos and apartment buildings in Chicago, <strong>Evanston<\/strong>, or <strong>Cicero<\/strong>, mitigation can involve:<\/p>\n<ul>\n<li>Shared piping chases or utility shafts<\/li>\n<li>Coordinating access to multiple units<\/li>\n<li>HOA approvals and building rules<\/li>\n<li>Testing multiple ground-contact units before and after mitigation<\/li>\n<\/ul>\n<p>A building-wide plan (test \u2192 prioritize ground-contact units \u2192 mitigate where needed \u2192 confirm with follow-up tests) tends to work best, especially where garden units are lived in year-round.<\/p>\n<h3>Brief safety note<\/h3>\n<p>If results come back high, follow <strong>EPA and Illinois guidance<\/strong> and work with a qualified radon professional to confirm levels and choose the right fix.<\/p>\n<hr \/>\n<h3>FAQ: Ground-contact units, condos, and rentals<\/h3>\n<p><strong>Does a first-floor unit need testing if there\u2019s a basement below?<\/strong><br \/>\nIf the basement is below and not living space, the first floor can still be affected\u2014especially if there are open stairwells, utility chases, or air movement from below. Testing the lowest lived-in level is still the priority, and additional testing can be added if needed.<\/p>\n<p><strong>I\u2019m on the 2nd or 3rd floor\u2014can I skip it?<\/strong><br \/>\nUpper floors often test lower, but \u201coften\u201d isn\u2019t \u201calways.\u201d If there\u2019s a known radon issue in the building, testing your unit can still be reasonable. Ground-contact units remain the first priority.<\/p>\n<p><strong>Can I test in a rental garden unit?<\/strong><br \/>\nUsually yes, with landlord permission. Many property managers appreciate a clear, documented result. Ask where they prefer placement so the test isn\u2019t disturbed.<\/p>\n<p><strong>If my neighbor tested low, am I in the clear?<\/strong><br \/>\nNot necessarily. Differences in cracks, sumps, ventilation, and unit layout can change results even next door or downstairs.<\/p>\n<p><strong>Do I need a professional test?<\/strong><br \/>\nDIY tests can be a good starting point when used correctly. For real estate transactions or when confirming elevated results, professional measurement is common.<\/p>\n<hr \/>\n<h2>Clear next steps checklist<\/h2>\n<ul>\n<li>Identify ground-contact spaces: garden unit, basement rooms, split-level lower level, slab-on-grade first floor\u2014especially the rooms you actually live in (sleep, work, relax).<\/li>\n<li>Prioritize the highest-risk locations first: in Chicago and close-in suburbs like <strong>Oak Park, Cicero, Evanston, Skokie, and Berwyn<\/strong>, that often means garden units and finished basements; in <strong>Naperville, Schaumburg, and Downers Grove<\/strong>, it\u2019s often basements and split-level lower floors.<\/li>\n<li>Choose the right test type: short-term for quick screening; long-term for a better year-round picture.<\/li>\n<li>Place the test correctly: lowest lived-in level, away from drafts, windows, kitchens, baths, and vents.<\/li>\n<li>Follow closed-house instructions (as required) and don\u2019t disturb the device.<\/li>\n<li>Record details: start\/end times, weather notes, HVAC use, and which room\/level was tested.<\/li>\n<li>Review results using EPA\/Illinois guidance and don\u2019t over-interpret neighborhood averages\u2014especially when comparing upper floors to ground-contact units.<\/li>\n<li>If elevated, plan next steps: confirm with follow-up testing if appropriate and contact a qualified mitigator.<\/li>\n<li>For multi-unit buildings: coordinate with your HOA\/landlord to test multiple ground-contact units first, then document outcomes for the building.<\/li>\n<li>Use local resources to compare context and plan testing across the metro: <a href=\"\/illinois\/chicago-metro\/\">Chicago, IL<\/a> and <a href=\"https:\/\/radonresources.com\/user-submitted-radon-levels\/\">User Submitted Radon Levels<\/a>.<\/li>\n<\/ul>\n<p>Radon in Chicago and across the metro isn\u2019t a \u201ccity vs suburb\u201d issue\u2014it\u2019s a <strong>ground-contact<\/strong> issue. If the space touches the ground, treat it as the priority and test it accordingly.<\/p>\n<div class=\"22ed2311db4594d186c610eb4750f4e6\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<a href=\"https:\/\/radonresources.com\/glp.php?camp=bc1\"><img decoding=\"async\" src=\"https:\/\/radonresources.com\/blog\/wp-content\/uploads\/2017\/02\/RR-Magnet-Lead-Image.jpg\" alt=\"RR lead magnet\"><\/a>\n<\/div>\n\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Radon in Chicago and the Surrounding Suburbs: Why Ground-Contact Units Matter Most Radon in Chicago is easy to underestimate because the region feels so built-up and vertical\u2014courtyard buildings, multi-flats, condos, and tight lot lines. But radon doesn\u2019t care what\u2019s happening at street level. It starts below the building, then follows the paths that connect soil [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":1993,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,13],"tags":[],"class_list":["post-1985","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","category-radon-resistant-home"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.3 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Radon in Chicago: Why Ground-Contact Units Matter - Blog<\/title>\n<meta name=\"description\" content=\"Learn why radon in Chicago varies block to block, which units are highest risk, and how to test basements and garden units across the metro.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/radonresources.com\/blog\/radon-in-chicago-why-ground-contact-units-matter\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Radon in Chicago: Why Ground-Contact Units Matter - 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