Sick building syndrome (SBS) is a condition where people develop health symptoms that are directly tied to time spent inside a particular building, yet no specific illness or cause can be pinpointed. The symptoms typically improve or disappear shortly after leaving the building. It’s most commonly reported in offices with sealed windows and mechanical ventilation, and it can affect a handful of people in one zone or spread across an entire floor.
Common Symptoms
The symptom list is broad, which is part of what makes SBS frustrating to pin down. The most frequently reported complaints include headaches, dizziness, nausea, eye irritation, nose and throat irritation, dry cough, dry or itchy skin, difficulty concentrating, fatigue, and heightened sensitivity to odors. Some people also experience hoarseness, cold or flu-like symptoms, and worsening asthma attacks.
These symptoms overlap with dozens of other conditions, from seasonal allergies to sleep deprivation. The distinguishing feature is timing: symptoms appear during or shortly after time in the building and resolve once you leave. If multiple coworkers in the same space report similar complaints, that pattern is a strong signal.
SBS vs. Building-Related Illness
There’s an important distinction between sick building syndrome and what’s called building-related illness (BRI). With SBS, the symptoms are real but no diagnosable disease can be identified, and the cause remains unclear. With BRI, a specific illness can be clinically defined and traced to a known contaminant in the building, such as Legionnaires’ disease from contaminated water systems or hypersensitivity pneumonitis from mold exposure.
In practice, SBS is a diagnosis of exclusion. If doctors can identify a pathogen or toxin causing your symptoms, that’s BRI. If they can’t, but the building connection is clear, that’s SBS.
What Causes It
No single cause explains every case, but research has identified several contributing factors that tend to overlap in problem buildings.
Volatile Organic Compounds
Indoor air often contains volatile organic compounds (VOCs) released by furniture, carpeting, paint, cleaning products, adhesives, and office equipment like printers. Specific chemicals linked to respiratory and mucosal symptoms include toluene, ethylbenzene, xylene, formaldehyde, and butyl acetate. These are especially concentrated in newly constructed or recently renovated buildings. Research suggests that total VOC levels above 3.0 mg/m³ in non-industrial indoor environments can harm health or comfort. Even at lower concentrations, every 100 parts per billion increase in total VOCs has been associated with a measurable rise in upper respiratory symptoms, dry throat, and irritability.
Poor Ventilation
Inadequate fresh air supply is one of the most consistent factors in SBS complaints. Many commercial buildings built since the 1970s were designed to be energy-efficient, with tightly sealed envelopes that reduce air exchange with the outdoors. When ventilation systems don’t bring in enough outside air, or when they recirculate stale air, indoor pollutants accumulate. ASHRAE Standard 62.1, the industry benchmark for ventilation design since 1973, sets minimum outdoor air ventilation rates specifically to prevent this kind of buildup.
The impact of fixing ventilation can be dramatic. In one study of nearly 1,400 office workers, moving from a poorly ventilated building to one with an improved ventilation system reduced symptom prevalence by 40% to 50% across all categories, including headaches, fatigue, skin complaints, and respiratory issues. More than 60% of workers who were symptomatic before the move became symptom-free afterward. Fewer than 15% developed new symptoms in the better-ventilated space.
Biological Contaminants
Mold, bacteria, and other microorganisms can grow in HVAC systems, ceiling tiles, carpeting, and anywhere moisture collects. These biological contaminants release particles and microbial VOCs into the air. Research in Northern European cities found that indoor concentrations of certain microbial compounds increased the risk of mucosal symptoms among building occupants. Poorly maintained HVAC systems are a common culprit, since condensation in ductwork and drain pans creates an ideal breeding ground.
Other Contributing Factors
Inadequate lighting, excessive noise, low humidity, high temperatures, and poor ergonomic design can all amplify SBS symptoms or create overlapping complaints. Psychological factors like job stress and lack of control over your work environment also correlate with higher symptom reporting, though this doesn’t mean the symptoms aren’t real. The interplay between physical air quality and workplace stress likely makes both worse.
Who Is Most Affected
SBS disproportionately affects people who work in large commercial buildings with centralized HVAC systems and sealed windows. Office workers are the most studied group. People with pre-existing allergies, asthma, or chemical sensitivities tend to react more strongly and at lower exposure levels. Some research also suggests that women report SBS symptoms more frequently, though it’s unclear whether this reflects biological differences, differences in the types of workspaces occupied, or differences in reporting patterns.
What You Can Do About It
If you suspect your building is making you sick, start by documenting your symptoms and when they occur. Note whether they improve on weekends, during vacations, or when you work from a different location. Talk to coworkers to see if others are experiencing similar issues. A pattern of complaints from multiple people in the same area is the strongest case you can bring to building management.
On the building side, the most effective intervention is improving ventilation. Increasing the supply of outdoor air, properly maintaining HVAC filters and ductwork, and ensuring drainage systems don’t harbor standing water can make a significant difference. Reducing indoor pollutant sources also helps: choosing low-VOC paints, adhesives, and furnishings during renovations, storing chemicals in well-ventilated areas, and running new equipment or materials in unoccupied spaces before people move in.
For individuals, practical steps include opening windows if possible, using a portable air purifier with a HEPA filter at your desk, taking regular breaks outside the building, and keeping your immediate workspace clean and free of dust. These won’t solve a systemic ventilation problem, but they can reduce your personal exposure while larger fixes are underway.
Employer Responsibilities
OSHA does not currently have specific indoor air quality standards for offices. However, the General Duty Clause of the Occupational Safety and Health Act requires employers to provide a workplace free from known hazards that could cause death or serious injury. Employers are expected to be reasonably aware of potential sources of poor air quality and to have the resources to recognize and control those hazards. They’re also required to inform employees of immediate dangers. Beyond federal requirements, specific state and local regulations may impose additional obligations for indoor air quality in commercial buildings.