According to the tax records, there was a permit pulled in April of 2000 to add on 120 sq. ft. of office space and 175 sq. ft. of storage. In order to find out if the area you are concerned about is the same area that was permitted as complete in 2001, you'd have to go down to the City to pull the actual plans. In order for a permit to be issued and consequently completed, there must be approved plans on file.
If your home has a non permitted addition, you may still sell the property. FHA allows unpermitted addisions, as long as the work was done in a workman like manner.