The Long Answer

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

When people smoke inside their home, the chemicals in tobacco smoke build up over time and leave toxic thirdhand smoke residue on carpets, furniture, walls, doors, and ceilings. This toxic residue lingers long after smoking stops and can remain after previous residents who smoked move out. Real estate agents know that evidence of smoking in a home — the smell of stale tobacco or stains on walls or fabrics — can reduce the selling price of a home by as much as 30%. That means if you live in a neighborhood where most homes sell for about $500,000, a similar home that smells like stale tobacco smoke will sell for around $350,000.

There are a few reasons why homes that have been smoked in often sell for less money.

• Most people do not like the smell of stale tobacco smoke.
• Many people experience negative physical symptoms when they smell stale tobacco smoke, such as shortness of breath, headaches, sore throat, or earaches.
• It is difficult and expensive to remove the toxic thirdhand smoke residue.

Most people want to buy houses that have not been smoked in, reducing the pool of potential buyers for a home where someone smoked. With fewer potential buyers, there is less competition to increase the price. Because real estate agents recognize that it is more difficult to sell a home that smells like stale tobacco smoke, it may be difficult to find an agent willing to list the home.

Required disclosure documents in many states, including California, currently do not ask about the smoking history of a home. However, the California Association of Realtors uses an additional document, called the Seller Property Questionnaire, that does ask sellers to disclose if they are aware of “any occupant of the property smoking or vaping any substance on or in the property, whether past or present.”

Even though few jurisdictions require tobacco use disclosure, most buyers and real estate agents are aware of the signs of indoor smoking and understand the challenges of cleaning thirdhand smoke inside a home.

If you are selling a home and someone in the household smokes, you should:

• Ask them to stop all smoking or vaping indoors immediately. That will reduce the build-up of thirdhand smoke.
• Hire a remediation expert to clean all walls, ceilings, floors, carpeting, furniture, fixtures, and windows.
• Inspect and clean or replace the heating and air conditioning duct system to attempt to remove thirdhand smoke from surfaces.

Depending on how much thirdhand smoke has accumulated, cleaning may be insufficient, and a full remediation may be required. Remediation includes drastic (and often expensive) measures, such as the removal and replacement of drywall, flooring, and the heating and air conditioning system.

If you are buying a home, you should:

• Ask the seller’s agent about the smoking history of the home.
• Inquire if there is an excessive use of air fresheners or candles which may be attempts to cover up unpleasant odors from stale tobacco smoke.
• Ask the home inspector to look for signs of tobacco use.

Tobacco smoke residue can significantly decrease your home’s value. To avoid bad news when you sell your home, don’t allow smoking or vaping on or in your property. If thirdhand smoke has already accumulated, consult a remediation expert to make necessary repairs and improvements. You’ll also want to disclose the information to your real estate agent and buyer.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: April 2025

Sources:

Klassen AC, Lee N, Lopez JP, et al. Realtors as partners in tobacco control: Results from a Pennsylvania survey. Tobacco Regulatory Science. 2020;6(6):392-404. doi: 10.18001/TRS.6.6.3

Matt GE, Quintana PJ, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1):e1. doi: 10.1136/tc.2010.037382

Seller Property Questionnaire. California Association of Realtors. 2023. https://thirdhandsmoke.org/wp-content/uploads/2024/11/SPQ.pdf

Getting Rid of Cigarette Smell in Your Home. This Old House. https://www.thisoldhouse.com/home-safety/21249597/understanding-thirdhand-smoke

Ura, Karley. Up in smoke: Smoking in the home can lower resale value by tens of thousands. Cision. 2013. https://www.newswire.ca/news-releases/up-in-smoke-smoking-in-the-home-can-lower-resale-value-by-tens-of-thousands-512275021.htm