Websites like Zillow.com claim to provide estimates of what your home is worth, and while this estimate might be somewhat accurate, the only way to get a true assessment of the value of your home is to have an appraisal done by a certified third-party professional.  There are a few situations where an appraisal is mandated, such as when you're buying and selling a home, refinancing or applying for a loan using real estate as security.

The appraiser's report can help determine a selling price, and it can provide owners with information about problems that are devaluing the home's worth and give insight about worthwhile fixes.  Appraisals are usually conducted after an offer has been made or to determine the initial value of a home as part of the selling process.  Keep in mind that to approve a loan, banks typically require an appraisal using their preferred appraisers to ensure the most accurate assessment, even if you've already had one done by another party.