The Elevation Certificate is performed for the purpose of rating the cost of flood insurance.  It reports the relative vertical distance above or below a base flood elevation from a Flood Insurance Rate Map (FIRM).  The FIRMs were produced by the Federal Emergency Management Agency of our federal government for the use in the National Flood Insurance Program (NFIP).  The FIRMs were made to give a quick idea on whether a property and building was in a special flood hazard area.  The FIRM typically shows no buildings and minor or residential streets are not shown.  So the surveyor is often called upon to measure the elevation of a building and report on an EC how far above or below the base flood elevation it is.