N.G.L. full name is Natural Ground Level.The natural ground level is termed as the level of the ground.The height of Natural ground level (NGL) is generally measured with the Mean-sea level.....
F.F.L. full name is Floor Finishing Level. The ground level inside the building is knowns Floor Finish level. This level is at the height of a minimum 150mm – 450mm from the Natural ground level (N.G.L)....
E.G.L. full name of Existing Ground Level. After earth filling of above natural ground level that above the level surface, this surface area called the existing ground level. E.G.L. normally after filling soil compaction.