The most accessible source of information on comparable sales is the public record. When someone buys a home the property is deeded from the seller to the buyer. In most circumstances, this deed is recorded at the local county recorder's office. They combine sales data with information already known about the property so they can assess property taxes correctly.
Provided there have been no additions to the property, the information available from the public record is usually correct regarding sales price, square footage, and numbers of rooms. This makes it easy to use the public record as a source of data for comparable sale information.
Accessing the data is another matter, at least for the general public. REALTOR®s can generally look up this information through title insurance companies. The title companies either compile the data directly from the county recorder's office or purchase if from other companies.
One problem with the public record is that it tends to run at least six to eight weeks behind. Add another four to six weeks for the typical escrow period and you can see the data is not current. The most current information is the most valuable.