We’re Hiring at Indoor Science! Learn more about our Job Openings.

Sick Building Syndrome – Questions To Answer!

water stains exterior

On many projects that I have worked on throughout the years, I have been asked to evaluate a building for “Sick Building Syndrome”.  Now, what is this syndrome? Is the building somehow sick? Not exactly. According to the EPA, sick building syndrome (or SBS) describes “situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building.”1

During the site assessments, the clients will complain of one or more different symptoms such as fatigue, nausea, throat irritation, headaches, trouble breathing or a host of other issues.  SBS can take place in a workplace or residential property. For the sake of this blog, I will focus on residential properties. In the following paragraphs, I will show the types of questions that I ask the client to help me narrow down the source of the problem.    

Do the symptoms go away when you leave the house?  

This is a sure-fire sign of sick building syndrome.  The length of time it takes for the symptoms to lessen can vary.  Some of my clients reported that when they took an extended weekend getaway or a long vacation, the symptoms would go away.  Other clients report that within an hour of leaving their home, they felt much better. 

How long have you been living in the home?

We have also had a number of clients report that they started feeling ill shortly after moving into their property.  Sometimes a client has been living in a property for a number of years and has felt perfectly fine until now. This could also be due to some concurrent illness or their immune system gradually deteriorating over time.   

But other times the symptoms can be associated with a specific change in the home.  This leads to the next question.

When did you first start feeling symptoms?

Another way of phrasing this could be “From the time everything was fine to the time that it wasn’t – what changed?”  This could involve extensive remodeling like a new kitchen or bathroom, painting, staining, caulking, etc. Perhaps the windows and/or roof were recently replaced which made the home more airtight.  Remodeling a home can involve a host of issues with volatile organic compounds (VOCs) that are off-gassing into the air and making people sick. If this is the case, a check of total volatile organic compounds levels can help determine if that is a possible cause of the symptoms.  

Are the symptoms worse in the morning or in the evening?

This question can also help in figuring out the source of the problem.  For instance, if a client’s symptoms appear to be worse in the morning, it could be an indication that the problem is in the bedroom where they are sleeping.  Going through an extensive examination and possible testing in this room can provide critical clues.   

On the other hand, if the symptoms are worse in the evening (ie after coming back from work) it may be an indication that the underlying cause is away from the property.

Are the symptoms worse in different seasons?  

If the problems occur during times of more extreme weather, such as a hot summer or cold winter, the issue may be associated with the HVAC system and ventilation.  I oftentimes ask a client if their systems are worse while the HVAC is running. Winter examples include condensation on cold walls and improper venting of furnaces. Summer examples include rainwater intrusion and condensation in crawl spaces

Moisture problems in the property?

Have you had any known leaks in the plumbing?  Are you aware of any roof leaks or humidity issues in the attic?  Have you had any flooding events in your basement or crawl space? Any one of these problems could be totaled up in a single word – “mold”!   A mold problem can wreak havoc for people with hypersensitivities. A moisture problem doesn’t even have to be recent for there to be a mold problem.  A past issue with dampness can mean elevated mold levels today.


By answering these questions, we improve our chances of solving the mystery of SBS.  In these types of situations, a trained indoor air quality consultant can be an invaluable resource.  As the old saying goes, “Knowledge is power”.  By answering these questions, we take the necessary steps in having a healthy home.

  1. https://www.epa.gov/sites/production/files/2014-08/documents/sick_building_factsheet.pdf https://www.epa.gov/sites/production/files/2014-08/documents/sick_building_factsheet.pdf

Ian Cull

Ian Cull is a nationally recognized expert in the field of indoor air quality. He is the Chief Science Officer of Indoor Science, a company he started in 2004. He speaks around the world on air quality topics and is a training provider of the Indoor Air Quality Association. Mr. Cull is a Licensed Professional Engineer (PE) and Certified Industrial Hygienist (CIH). His degree is in Environmental Engineering from the University of Illinois - Urbana Champaign. Mr. Cull has developed 50 air quality related courses for the IAQA University and is the author of the book, “Fundamentals of Mold Remediation”. In his words… “Besides being passionate about indoor air quality, I enjoy cycling, music, the Chicago Bulls, and having fun with my three kids.”

2 thoughts on “Sick Building Syndrome – Questions To Answer!

    Hi Scott. I value the Indoor Science updated blogs. Thank you.

    The main question I am struggling to answer is what steps can one take when mold has been found and removed, areas have been remediated, but you believe/confirm and mycotoxins are in the house? It seems like the proverbial “elephant in the room” for the mold/IAQ community but what methods, protocols, or research can you reference to support this issue?


    I’m am not quite sure I fully understand your question. When mold is remediated properly, there are three issues that need to be addressed. The source of the moisture needs to be repaired, the mold needs to be physically removed, and the air needs to be cleaned of excess mold spores. Once that has been performed, the remediation should be complete.