Mold and mildew create strong smells and can cost a lot of money to fix what is letting the moisture into the home.
When you're looking for a new home, be sure to look with your nose, not just your eyes. A bad smell may be a sign of a larger issue that could cost you dearly.
Take a big whiff of the air when you're outside the house. Do you smell sewage, gas or anything else that's unpleasant? Sewage systems in homes older than 20 years often get clogged or damaged by tree roots. If you're buying an older home, sewer and plumbing companies can send a camera through the pipes and determine if there are any blockages or breaks.
Keep your nose at attention inside the house as well. Do you smell cigarette, pet or mildew odors? If you can't smell anything but the huge baskets of potpourri all over the house, this could be a red flag as well.
Pet and smoke smells can be minimized with a little cleaning and elbow grease, but will take a long time to fully dissipate. Mildew and mold smells indicate a much larger problem -- mold removal can cost thousands of dollars, plus whatever's letting moisture in will need to be fixed.
If you notice a strong smell but are interested in the house, hire an inspector who will pay special attention to unmasking the foul odor.