Whether you are selling your home yourself, or using a Realtor (which I recommend), you should have an accurate measurement by a Licensed or Certified Appraiser.
Williamsburg is currently in a tight market where every square foot counts in pricing a home. Many times the living area listed at the Assessor's office does not include a finished bonus room, or the plans changed when the house was being built. Either pull out an old appraisal, which should have a building sketch, or have an appraiser come out and measure your home. Our fee for measuring is typically between $65.00 and $85.00. If your square footage increases by just 100 square feet, your value could increase from $2,000 to $8,500.