LiDAR building heights do not make sense

[TiffanyBledsoe]

I want to use LiDAR data for building height information to make 3D buildings in my study area. I have LiDAR data for buildings in my study area. I have displayed the data in ArcGIS 10 and have turned on the label feature for the z values. I want to extract the building heights to add to my building footprints shapefile.

My problem is the heights, z, in the LiDAR data does not make sense. I understand that the values are in meters from sea level. My study area is 213 meters above sea level. I obtained this information from USGS and confirmed with a local weather station information. I have building heights for a couple of buildings but not all, there are 33 total buildings in my study area. I was checking to make sure the LiDAR data matched with my known building heights and they do not. For example, LiDAR has the height of a corner as 214, therefore, after subtracting 214m-213m=1 m which equals just over 3 feet. The building is 2 stories. Some of my heights are even below sea level.

I am very new to LiDAR data and 3D analyst. If anyone could help me as to why my heights are not making any sense that would be great.

[JeffreySwain]

Without seeing your lidar data, it is difficult to know, but perhaps you might need to consider whether the lidar data was obtained or generated for the buildings. Perhaps the values created reflect the height above the ground rather than the true elevation.  In that case, if you added the building values to ground elevation you would have a building with a height of 427 or in your case, 214 meters above the ground.  I have not seen much lidar like this, but perhaps you should consider it.