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April 2014

Solve Problems that Stymie Home Sales

Odor and Indoor Air Quality

By NWREporter

April 2014

by Cheri Zehner, MPH

We use all of our senses when assessing the appeal of a prospective home.  Most homebuyers are looking for features and amenities that you can see, such as curb appeal, family rooms, and walk-in closets.  What about the amenities that you can't see?  No matter how visually appealing a home might be, if the house has an odor it will be difficult to sell. 

Instinctively, odors inform us that there is something wrong in the environment.  As familiar as we all are with what I'm describing, most folks find odors to be mysterious.  Odor issues can be complicated.  For starters, odor descriptions are subjective. I am frequently amused by how different a client's odor description is from my own perception.  Also, heat, humidity, ventilation, and weather can all influence the detection of an odor, not to mention the actual source of the odor. 

Some odors are caused by conditions that are easily rectified.  For example, "old folks" odor is usually from carpet and upholstered furnishings heavily laden with dander (skin flakes) - a predominant component of house dust.  Usually, carpet and upholstery steam cleaning can solve this issue.  Sometimes carpet removal, particularly if the carpet is over 10 years old, is a prudent approach. 

If a urine odor is detected, the use of a black light flashlight can help locate urine spots on flooring to verify the source.  The same flashlight will disclose rodent runways, as rodents tend to urinate on their frequented paths, marking their territory. 

If the home has a musty odor that means there is mold growth in the house.  Mold only grows where there is high humidity or water intrusion.  Indoor relative humidity measured at 60 per cent and higher can support mold growth.  Look for discoloration and irregularities on walls and other building materials that indicate water intrusion and suspect mold growth.  Correcting the water problem is the first step. 

Poor indoor air quality (IAQ), sometimes evidenced by odors, is indicative of unappealing or unacceptable conditions.  The real estate industry has its joke about the three rules of real estate being - "location, location, location".  Industrial hygienists have three similar rules - "control the source; control the source; control the source."  This means that it is most prudent to find and control the root of a problem and correct it.   Conditions leading to poor IAQ warrant being addressed head-on.

Poor indoor air quality is nothing to sneeze at.  The EPA and its Science Advisory Board have consistently ranked indoor air pollution among the top five environmental risks to our health.  Studies have shown that the levels of many airborne pollutants may be 25 to 100 times higher indoors than outdoors.  According to the American College of Allergists, 50% of all illnesses are caused or aggravated by contaminated indoor air.

Asthma is the single largest cause of hospital visits by children.  Asthma rates in the U.S. have increased from 7.3% in 2001 to 8.4% in 2010.  There are about 25.7 million persons in the U.S. with asthma. 

There are many factors that influence IAQ.  Many of them have to do with the activities and habits of the occupants.  Other factors are derived from the building materials and characteristics of the dwelling.  Indoor air contaminants generally fall into two categories: particles and gases.  Particles include asbestos, house dust, organic matter (i.e., dander, dust mites, mold and bacteria), combustion products, and heavy metals. Gasses include volatile organic compounds (VOCs), semi-volatile compounds, carbon monoxide (CO), radon, and combustion products.

A few of these contaminants are regulated, such as asbestos containing materials, the heavy metal, lead, and radon gas.  EPA has a wealth of information on their website informing home owners of their risks and responsibilities.  Also, carbon monoxide (CO) alarms are now required in homes and can be found at most hardware stores. 

Buying a "green" home is no guarantee that the home has healthy air.  In fact, energy conservation has created unintended consequences of reducing the air changes in a home and allowing contaminants to accumulate indoors. 

Creating a healthy indoor environment does not always require a big budget.  Here are some helpful hints:

* Housekeeping is a means for getting a huge bang for the buck.  Homes need to be cleaned for health's sake not for appearance's sake.  The most effective way to control household dust (chock-a-block full of contaminants, allergens and irritants) is frequent, and thorough carpet vacuuming.  This fact has been proven in numerous published studies.  Vacuuming should be done at least once per week, or more, depending on how many kids, pets and activities are in a household.  Limit clutter so that the house can be easily dusted.   Smooth floors can be damp mopped with a dilute vinegar or mild detergent solution.   

* Choose household cleaners that have low toxicity and are fragrance free.  Use the Green Cleaning Recipes found on many websites such as those for the Environmental Protection Agency, Washington State, or American Lung Association of Washington.  Not only are these recipes low toxicity, they are also low cost and effective.  Fragrance can be an irritant and an allergen.  It is also an ingredient in products that can be likened to a Trojan horse filled with unidentified, unnecessary and unwanted chemicals entering the home. 

* Maintain filtration systems on forced air furnaces.  Filtration systems are helpful in controlling house dust but do not come close to the impact of frequent, thorough vacuuming.  Check with the furnace manufacturer to use the most effective filter possible.  General recommendations are to change filters with every season.  Electronic cleaning systems must be diligently maintained according to the manufacturer's instructions in order to keep them at peak performance. 

* Control moisture intrusion and humidity in the home.  Always use bathroom fans while showering and stove hoods while cooking to maintain relative humidity below 60%.  Humidity at or above 60% can set conditions for mold growth.

* Repair all water leaks.  Water is the cause of all mold growth.  If there is no water, mold cannot grow.  Molds, like plants, have environmental niches where they thrive.  Some can thrive with little water while others prefer a soggy environment.      

* Pay attention to what you can't see.  Crawl spaces, attics and wall cavities are part of the house, even though not readily visible, air can readily move from these areas into the living areas of the home.  Make sure that the crawl space vapor barrier is in sound condition and that the crawl space is free of standing water, pests and debris. 

* Ventilation is necessary in homes to bring fresh air in and purge contaminants out.  Think of ventilation as breathing.  A house needs to breath.  Sometimes this need is trumped by the desire to conserve energy.  Windows or fresh air vent openings should be equivalent to at least 4% of a room's floor area, or there should be a mechanical ventilation system capable of producing 0.35 air changes per hour in a room.  A whole-house mechanical ventilation system should be capable of supplying 15 cubic feet per minute per occupant.

According to the Washington State University Energy Extension Program a 2500 square foot, 3-bedroom home, is required to be equipped with a 60 cubic-feet-per-minute ventilation fan, continuously operating.   The ventilation fan energy cost is about 3¢/day.  Heat loss from fresh air entering the house is about 22¢ to 31¢ per day.  The total annual cost is about $130.  The median charge per emergency room visit for asthma is $2,900 (Washington State Hospital Association). 

* Purchasing building products with low or no off gassing of VOCs is becoming easier, as more certified products reach the market.  Many brands of low and no VOC paints are now on the market at a reasonable price.  When low or no VOC products are cost-prohibitive, consider second hand or reusable resources. 

* Combustion sources are a significant source of indoor pollution and can be a strong asthma trigger.  They can also be a source of deadly carbon monoxide poisoning.  Make sure that all gas-fired appliances such as furnaces, stoves and dryers are maintained and in good working condition.  Wood burning stoves are a significant source of particulate matter and gases, causing a myriad of adverse health effects.  Make sure that wood burning stoves meet current EPA standards and consider changing to a less polluting energy source.  Though candles can create a pleasant ambiance in a home they also produce air pollution.  Scented candles add a cocktail of chemicals in addition to combustion contaminants.   Refrain from their use. 

Housekeeping for health, adequate ventilation, control of combustion, use of safe cleaning products and limiting fragrance (cleaning, laundry and personal-care products) are low-cost means of improving indoor air quality.  Controlling water leaks and humidity and performing building maintenance are necessary for maintaining the integrity of the building structure and also healthy IAQ.  Identifying odor sources and not attempting to mask odors with fragrance is the most prudent means of correcting not only IAQ but building integrity issues and the value of your real estate investment.  

Cheri ZehnerCheri Zehner, Industrial Hygienist, has over 20 years of experience in public health and environmental health programs and 15 years performing indoor air quality investigations. She is a certified instructor, teaching a Clock Hour course on Indoor Air Quality for Real Estate Professionals. Additionally, she has worked on US Green Building Council, Leadership in Energy and Environmental Design (LEED) projects, evaluating air quality in new construction.  She holds a Master's Degree in Public Health and Bachelor's Degree in Environmental Health, both from the University of Washington.  For more information visit www.cherizehner.com or call (206) 799-6382.